chore: release v2.4

- Add theme system (Dark/Light palettes, ModernTheme, ThemeManager) - Add InputDialog, Spinner common view - Add DuplicatesCsvExportService - Refresh views, dialogs, and view models across tabs - Update localization strings (en/fr) - Tweak services (transfer, permissions, search, user access, ownership elevation, bulk operations) Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-04-20 11:23:11 +02:00
parent 8f30a60d2a
commit 12dd1de9f2
93 changed files with 8708 additions and 1159 deletions
@@ -2,20 +2,40 @@ using System.Globalization;
 using System.IO;
 using System.Text;
 using CsvHelper;
+using CsvHelper.Configuration;
 using SharepointToolbox.Core.Models;
+using SharepointToolbox.Localization;

 namespace SharepointToolbox.Services.Export;

+/// <summary>
+/// Exports the failed subset of a <see cref="BulkOperationSummary{T}"/> run
+/// to CSV. CsvHelper is used so the <typeparamref name="T"/> payload's
+/// properties become columns automatically, plus one error-message and one
+/// timestamp column appended at the end.
+/// </summary>
 public class BulkResultCsvExportService
 {
+    private static readonly CsvConfiguration CsvConfig = new(CultureInfo.InvariantCulture)
+    {
+        // Prevent CSV formula injection: prefix =, +, -, @, tab, CR with single quote
+        InjectionOptions = InjectionOptions.Escape,
+    };
+
+    /// <summary>
+    /// Builds a CSV containing only items whose <see cref="BulkItemResult{T}.IsSuccess"/>
+    /// is <c>false</c>. Columns: every public property of <typeparamref name="T"/>
+    /// followed by Error and Timestamp (ISO-8601).
+    /// </summary>
    public string BuildFailedItemsCsv<T>(IReadOnlyList<BulkItemResult<T>> failedItems)
    {
+        var TL = TranslationSource.Instance;
        using var writer = new StringWriter();
-        using var csv = new CsvWriter(writer, CultureInfo.InvariantCulture);
+        using var csv = new CsvWriter(writer, CsvConfig);

        csv.WriteHeader<T>();
-        csv.WriteField("Error");
-        csv.WriteField("Timestamp");
+        csv.WriteField(TL["report.col.error"]);
+        csv.WriteField(TL["report.col.timestamp"]);
        csv.NextRecord();

        foreach (var item in failedItems.Where(r => !r.IsSuccess))
@@ -29,12 +49,13 @@ public class BulkResultCsvExportService
        return writer.ToString();
    }

+    /// <summary>Writes the failed-items CSV to <paramref name="filePath"/> with UTF-8 BOM.</summary>
    public async Task WriteFailedItemsCsvAsync<T>(
        IReadOnlyList<BulkItemResult<T>> failedItems,
        string filePath,
        CancellationToken ct)
    {
        var content = BuildFailedItemsCsv(failedItems);
-        await System.IO.File.WriteAllTextAsync(filePath, content, new UTF8Encoding(true), ct);
+        await ExportFileWriter.WriteCsvAsync(filePath, content, ct);
    }
 }
@@ -1,6 +1,7 @@
 using System.IO;
 using System.Text;
 using SharepointToolbox.Core.Models;
+using SharepointToolbox.Localization;

 namespace SharepointToolbox.Services.Export;

@@ -10,8 +11,11 @@ namespace SharepointToolbox.Services.Export;
 /// </summary>
 public class CsvExportService
 {
-    private const string Header =
-        "\"Object\",\"Title\",\"URL\",\"HasUniquePermissions\",\"Users\",\"UserLogins\",\"Type\",\"Permissions\",\"GrantedThrough\"";
+    private static string BuildHeader()
+    {
+        var T = TranslationSource.Instance;
+        return $"\"{T["report.col.object"]}\",\"{T["report.col.title"]}\",\"{T["report.col.url"]}\",\"HasUniquePermissions\",\"Users\",\"UserLogins\",\"Type\",\"Permissions\",\"GrantedThrough\"";
+    }

    /// <summary>
    /// Builds a CSV string from the supplied permission entries.
@@ -20,7 +24,7 @@ public class CsvExportService
    public string BuildCsv(IReadOnlyList<PermissionEntry> entries)
    {
        var sb = new StringBuilder();
-        sb.AppendLine(Header);
+        sb.AppendLine(BuildHeader());

        // Merge: group by (Users, PermissionLevels, GrantedThrough) — port of PS Merge-PermissionRows
        var merged = entries
@@ -55,14 +59,17 @@ public class CsvExportService
    public async Task WriteAsync(IReadOnlyList<PermissionEntry> entries, string filePath, CancellationToken ct)
    {
        var csv = BuildCsv(entries);
-        await File.WriteAllTextAsync(filePath, csv, new UTF8Encoding(encoderShouldEmitUTF8Identifier: true), ct);
+        await ExportFileWriter.WriteCsvAsync(filePath, csv, ct);
    }

    /// <summary>
    /// Header for simplified CSV export — includes "SimplifiedLabels" and "RiskLevel" columns.
    /// </summary>
-    private const string SimplifiedHeader =
-        "\"Object\",\"Title\",\"URL\",\"HasUniquePermissions\",\"Users\",\"UserLogins\",\"Type\",\"Permissions\",\"SimplifiedLabels\",\"RiskLevel\",\"GrantedThrough\"";
+    private static string BuildSimplifiedHeader()
+    {
+        var T = TranslationSource.Instance;
+        return $"\"{T["report.col.object"]}\",\"{T["report.col.title"]}\",\"{T["report.col.url"]}\",\"HasUniquePermissions\",\"Users\",\"UserLogins\",\"Type\",\"Permissions\",\"SimplifiedLabels\",\"RiskLevel\",\"GrantedThrough\"";
+    }

    /// <summary>
    /// Builds a CSV string from simplified permission entries.
@@ -72,7 +79,7 @@ public class CsvExportService
    public string BuildCsv(IReadOnlyList<SimplifiedPermissionEntry> entries)
    {
        var sb = new StringBuilder();
-        sb.AppendLine(SimplifiedHeader);
+        sb.AppendLine(BuildSimplifiedHeader());

        var merged = entries
            .GroupBy(e => (e.Users, e.PermissionLevels, e.GrantedThrough))
@@ -109,13 +116,57 @@ public class CsvExportService
    public async Task WriteAsync(IReadOnlyList<SimplifiedPermissionEntry> entries, string filePath, CancellationToken ct)
    {
        var csv = BuildCsv(entries);
-        await File.WriteAllTextAsync(filePath, csv, new UTF8Encoding(encoderShouldEmitUTF8Identifier: true), ct);
+        await ExportFileWriter.WriteCsvAsync(filePath, csv, ct);
    }

-    /// <summary>RFC 4180 CSV field escaping: wrap in double quotes, double internal quotes.</summary>
-    private static string Csv(string value)
+    /// <summary>
+    /// Writes permission entries with optional per-site partitioning.
+    /// Single → writes one file at <paramref name="basePath"/>.
+    /// BySite → one file per site-collection URL, suffixed on the base path.
+    /// </summary>
+    public Task WriteAsync(
+        IReadOnlyList<PermissionEntry> entries,
+        string basePath,
+        ReportSplitMode splitMode,
+        CancellationToken ct)
+        => ReportSplitHelper.WritePartitionedAsync(
+            entries, basePath, splitMode,
+            PartitionBySite,
+            (part, path, c) => WriteAsync(part, path, c),
+            ct);
+
+    /// <summary>Simplified-entry split variant.</summary>
+    public Task WriteAsync(
+        IReadOnlyList<SimplifiedPermissionEntry> entries,
+        string basePath,
+        ReportSplitMode splitMode,
+        CancellationToken ct)
+        => ReportSplitHelper.WritePartitionedAsync(
+            entries, basePath, splitMode,
+            PartitionBySite,
+            (part, path, c) => WriteAsync(part, path, c),
+            ct);
+
+    internal static IEnumerable<(string Label, IReadOnlyList<PermissionEntry> Partition)> PartitionBySite(
+        IReadOnlyList<PermissionEntry> entries)
    {
-        if (string.IsNullOrEmpty(value)) return "\"\"";
-        return $"\"{value.Replace("\"", "\"\"")}\"";
+        return entries
+            .GroupBy(e => ReportSplitHelper.DeriveSiteCollectionUrl(e.Url), StringComparer.OrdinalIgnoreCase)
+            .Select(g => (
+                Label: ReportSplitHelper.DeriveSiteLabel(g.Key),
+                Partition: (IReadOnlyList<PermissionEntry>)g.ToList()));
    }
+
+    internal static IEnumerable<(string Label, IReadOnlyList<SimplifiedPermissionEntry> Partition)> PartitionBySite(
+        IReadOnlyList<SimplifiedPermissionEntry> entries)
+    {
+        return entries
+            .GroupBy(e => ReportSplitHelper.DeriveSiteCollectionUrl(e.Url), StringComparer.OrdinalIgnoreCase)
+            .Select(g => (
+                Label: ReportSplitHelper.DeriveSiteLabel(g.Key),
+                Partition: (IReadOnlyList<SimplifiedPermissionEntry>)g.ToList()));
+    }
+
+    /// <summary>RFC 4180 CSV field escaping with formula-injection guard.</summary>
+    private static string Csv(string value) => CsvSanitizer.Escape(value);
 }
@@ -0,0 +1,47 @@
+namespace SharepointToolbox.Services.Export;
+
+/// <summary>
+/// CSV field sanitization. Adds RFC 4180 quoting plus formula-injection
+/// protection: Excel and other spreadsheet apps treat cells starting with
+/// '=', '+', '-', '@', tab, or CR as formulas. Prefixing with a single
+/// quote neutralizes the formula while remaining readable.
+/// </summary>
+internal static class CsvSanitizer
+{
+    /// <summary>
+    /// Escapes a value for inclusion in a CSV row. Always wraps in double
+    /// quotes. Doubles internal quotes per RFC 4180. Prepends an apostrophe
+    /// when the value begins with a character a spreadsheet would evaluate.
+    /// </summary>
+    public static string Escape(string? value)
+    {
+        if (string.IsNullOrEmpty(value)) return "\"\"";
+        var safe = NeutralizeFormulaPrefix(value).Replace("\"", "\"\"");
+        return $"\"{safe}\"";
+    }
+
+    /// <summary>
+    /// Minimal quoting variant: only wraps in quotes when the value contains
+    /// a delimiter, quote, or newline. Still guards against formula injection.
+    /// </summary>
+    public static string EscapeMinimal(string? value)
+    {
+        if (string.IsNullOrEmpty(value)) return string.Empty;
+        var safe = NeutralizeFormulaPrefix(value);
+        if (safe.Contains(',') || safe.Contains('"') || safe.Contains('\n') || safe.Contains('\r'))
+            return $"\"{safe.Replace("\"", "\"\"")}\"";
+        return safe;
+    }
+
+    private static string NeutralizeFormulaPrefix(string value)
+    {
+        if (value.Length == 0) return value;
+        char first = value[0];
+        if (first == '=' || first == '+' || first == '-' || first == '@'
+            || first == '\t' || first == '\r')
+        {
+            return "'" + value;
+        }
+        return value;
+    }
+}
@@ -0,0 +1,112 @@
+using System.IO;
+using System.Text;
+using SharepointToolbox.Core.Models;
+using SharepointToolbox.Localization;
+
+namespace SharepointToolbox.Services.Export;
+
+/// <summary>
+/// Exports DuplicateGroup list to CSV. Each duplicate item becomes one row;
+/// the Group column ties copies together and a Copies column gives the group size.
+/// Header row is built at write-time so culture switches are honoured.
+/// </summary>
+public class DuplicatesCsvExportService
+{
+    /// <summary>Writes the CSV to <paramref name="filePath"/> with UTF-8 BOM (Excel-compatible).</summary>
+    public async Task WriteAsync(
+        IReadOnlyList<DuplicateGroup> groups,
+        string filePath,
+        CancellationToken ct)
+    {
+        var csv = BuildCsv(groups);
+        await ExportFileWriter.WriteCsvAsync(filePath, csv, ct);
+    }
+
+    /// <summary>
+    /// Writes one or more CSVs depending on <paramref name="splitMode"/>.
+    /// Single → <paramref name="basePath"/> as-is. BySite → one file per site,
+    /// filenames derived from <paramref name="basePath"/> with a site suffix.
+    /// </summary>
+    public Task WriteAsync(
+        IReadOnlyList<DuplicateGroup> groups,
+        string basePath,
+        ReportSplitMode splitMode,
+        CancellationToken ct)
+        => ReportSplitHelper.WritePartitionedAsync(
+            groups, basePath, splitMode,
+            PartitionBySite,
+            (part, path, c) => WriteAsync(part, path, c),
+            ct);
+
+    internal static IEnumerable<(string Label, IReadOnlyList<DuplicateGroup> Partition)> PartitionBySite(
+        IReadOnlyList<DuplicateGroup> groups)
+    {
+        return groups
+            .GroupBy(g =>
+            {
+                var first = g.Items.FirstOrDefault();
+                return (Url: first?.SiteUrl ?? string.Empty, Title: first?.SiteTitle ?? string.Empty);
+            })
+            .Select(g => (
+                Label: ReportSplitHelper.DeriveSiteLabel(g.Key.Url, g.Key.Title),
+                Partition: (IReadOnlyList<DuplicateGroup>)g.ToList()));
+    }
+
+    /// <summary>
+    /// Builds the CSV payload. Emits a header summary (group count, generated
+    /// timestamp), then one row per duplicate item with its group index and
+    /// group size. CSV fields are escaped via <see cref="CsvSanitizer.Escape"/>.
+    /// </summary>
+    public string BuildCsv(IReadOnlyList<DuplicateGroup> groups)
+    {
+        var T = TranslationSource.Instance;
+        var sb = new StringBuilder();
+
+        // Summary
+        sb.AppendLine($"\"{T["report.title.duplicates_short"]}\"");
+        sb.AppendLine($"\"{T["report.text.duplicate_groups_found"]}\",\"{groups.Count}\"");
+        sb.AppendLine($"\"{T["report.text.generated"]}\",\"{DateTime.Now:yyyy-MM-dd HH:mm:ss}\"");
+        sb.AppendLine();
+
+        // Header
+        sb.AppendLine(string.Join(",", new[]
+        {
+            Csv(T["report.col.number"]),
+            Csv(T["report.col.group"]),
+            Csv(T["report.text.copies"]),
+            Csv(T["report.col.site"]),
+            Csv(T["report.col.name"]),
+            Csv(T["report.col.library"]),
+            Csv(T["report.col.path"]),
+            Csv(T["report.col.size_bytes"]),
+            Csv(T["report.col.created"]),
+            Csv(T["report.col.modified"]),
+        }));
+
+        foreach (var g in groups)
+        {
+            int i = 0;
+            foreach (var item in g.Items)
+            {
+                i++;
+                sb.AppendLine(string.Join(",", new[]
+                {
+                    Csv(i.ToString()),
+                    Csv(g.Name),
+                    Csv(g.Items.Count.ToString()),
+                    Csv(item.SiteTitle),
+                    Csv(item.Name),
+                    Csv(item.Library),
+                    Csv(item.Path),
+                    Csv(item.SizeBytes?.ToString() ?? string.Empty),
+                    Csv(item.Created?.ToString("yyyy-MM-dd") ?? string.Empty),
+                    Csv(item.Modified?.ToString("yyyy-MM-dd") ?? string.Empty),
+                }));
+            }
+        }
+
+        return sb.ToString();
+    }
+
+    private static string Csv(string value) => CsvSanitizer.Escape(value);
+}
@@ -1,4 +1,5 @@
 using SharepointToolbox.Core.Models;
+using SharepointToolbox.Localization;
 using System.Text;

 namespace SharepointToolbox.Services.Export;
@@ -10,17 +11,23 @@ namespace SharepointToolbox.Services.Export;
 /// </summary>
 public class DuplicatesHtmlExportService
 {
+    /// <summary>
+    /// Builds a self-contained HTML string rendering one collapsible card per
+    /// <see cref="DuplicateGroup"/>. The document ships with inline CSS and a
+    /// tiny JS toggle so no external assets are needed.
+    /// </summary>
    public string BuildHtml(IReadOnlyList<DuplicateGroup> groups, ReportBranding? branding = null)
    {
+        var T = TranslationSource.Instance;
        var sb = new StringBuilder();

+        sb.AppendLine("<!DOCTYPE html>");
+        sb.AppendLine("<html lang=\"en\">");
+        sb.AppendLine("<head>");
+        sb.AppendLine("<meta charset=\"UTF-8\">");
+        sb.AppendLine("<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">");
+        sb.AppendLine($"<title>{T["report.title.duplicates"]}</title>");
        sb.AppendLine("""
-            <!DOCTYPE html>
-            <html lang="en">
-            <head>
-            <meta charset="UTF-8">
-            <meta name="viewport" content="width=device-width, initial-scale=1.0">
-            <title>SharePoint Duplicate Detection Report</title>
            <style>
              body { font-family: 'Segoe UI', Arial, sans-serif; font-size: 13px; margin: 20px; background: #f5f5f5; }
              h1 { color: #0078d4; }
@@ -54,11 +61,9 @@ public class DuplicatesHtmlExportService
            <body>
            """);
        sb.Append(BrandingHtmlHelper.BuildBrandingHeader(branding));
-        sb.AppendLine("""
-            <h1>Duplicate Detection Report</h1>
-            """);
+        sb.AppendLine($"<h1>{T["report.title.duplicates_short"]}</h1>");

-        sb.AppendLine($"<p class=\"summary\">{groups.Count:N0} duplicate group(s) found.</p>");
+        sb.AppendLine($"<p class=\"summary\">{groups.Count:N0} {T["report.text.duplicate_groups_found"]}</p>");

        for (int i = 0; i < groups.Count; i++)
        {
@@ -70,19 +75,19 @@ public class DuplicatesHtmlExportService
                <div class="group-card">
                  <div class="group-header" onclick="toggleGroup({i})">
                    <span class="group-name">{H(g.Name)}</span>
-                    <span class="badge {badgeClass}">{count} copies</span>
+                    <span class="badge {badgeClass}">{count} {T["report.text.copies"]}</span>
                  </div>
                  <div class="group-body" id="gb-{i}">
                    <table>
                      <thead>
                        <tr>
-                          <th>#</th>
-                          <th>Name</th>
-                          <th>Library</th>
-                          <th>Path</th>
-                          <th>Size</th>
-                          <th>Created</th>
-                          <th>Modified</th>
+                          <th>{T["report.col.number"]}</th>
+                          <th>{T["report.col.name"]}</th>
+                          <th>{T["report.col.library"]}</th>
+                          <th>{T["report.col.path"]}</th>
+                          <th>{T["report.col.size"]}</th>
+                          <th>{T["report.col.created"]}</th>
+                          <th>{T["report.col.modified"]}</th>
                        </tr>
                      </thead>
                      <tbody>
@@ -116,18 +121,59 @@ public class DuplicatesHtmlExportService
                """);
        }

-        sb.AppendLine($"<p class=\"generated\">Generated: {DateTime.Now:yyyy-MM-dd HH:mm}</p>");
+        sb.AppendLine($"<p class=\"generated\">{T["report.text.generated_colon"]} {DateTime.Now:yyyy-MM-dd HH:mm}</p>");
        sb.AppendLine("</body></html>");

        return sb.ToString();
    }

+    /// <summary>Writes the HTML report to the specified file path using UTF-8.</summary>
    public async Task WriteAsync(IReadOnlyList<DuplicateGroup> groups, string filePath, CancellationToken ct, ReportBranding? branding = null)
    {
        var html = BuildHtml(groups, branding);
        await System.IO.File.WriteAllTextAsync(filePath, html, Encoding.UTF8, ct);
    }

+    /// <summary>
+    /// Writes one or more HTML reports depending on <paramref name="splitMode"/> and
+    /// <paramref name="layout"/>. Single → one file. BySite + SeparateFiles → one
+    /// file per site. BySite + SingleTabbed → one file with per-site iframe tabs.
+    /// </summary>
+    public async Task WriteAsync(
+        IReadOnlyList<DuplicateGroup> groups,
+        string basePath,
+        ReportSplitMode splitMode,
+        HtmlSplitLayout layout,
+        CancellationToken ct,
+        ReportBranding? branding = null)
+    {
+        if (splitMode != ReportSplitMode.BySite)
+        {
+            await WriteAsync(groups, basePath, ct, branding);
+            return;
+        }
+
+        var partitions = DuplicatesCsvExportService.PartitionBySite(groups).ToList();
+
+        if (layout == HtmlSplitLayout.SingleTabbed)
+        {
+            var parts = partitions
+                .Select(p => (p.Label, Html: BuildHtml(p.Partition, branding)))
+                .ToList();
+            var T = TranslationSource.Instance;
+            var tabbed = ReportSplitHelper.BuildTabbedHtml(parts, T["report.title.duplicates_short"]);
+            await System.IO.File.WriteAllTextAsync(basePath, tabbed, Encoding.UTF8, ct);
+            return;
+        }
+
+        foreach (var partition in partitions)
+        {
+            ct.ThrowIfCancellationRequested();
+            var path = ReportSplitHelper.BuildPartitionPath(basePath, partition.Label);
+            await WriteAsync(partition.Partition, path, ct, branding);
+        }
+    }
+
    private static string H(string value) =>
        System.Net.WebUtility.HtmlEncode(value ?? string.Empty);

@@ -0,0 +1,27 @@
+using System.IO;
+using System.Text;
+
+namespace SharepointToolbox.Services.Export;
+
+/// <summary>
+/// Central file-write plumbing for export services so every CSV and HTML
+/// artefact gets a consistent encoding: CSV files are written with a UTF-8
+/// BOM (required for Excel to detect the encoding when opening a
+/// double-clicked .csv), HTML files are written without a BOM (some browsers
+/// and iframe <c>srcdoc</c> paths render the BOM as a visible character).
+/// Export services should call these helpers rather than constructing
+/// <see cref="UTF8Encoding"/> inline.
+/// </summary>
+internal static class ExportFileWriter
+{
+    private static readonly UTF8Encoding Utf8WithBom = new(encoderShouldEmitUTF8Identifier: true);
+    private static readonly UTF8Encoding Utf8NoBom   = new(encoderShouldEmitUTF8Identifier: false);
+
+    /// <summary>Writes <paramref name="csv"/> to <paramref name="filePath"/> as UTF-8 with BOM.</summary>
+    public static Task WriteCsvAsync(string filePath, string csv, CancellationToken ct)
+        => File.WriteAllTextAsync(filePath, csv, Utf8WithBom, ct);
+
+    /// <summary>Writes <paramref name="html"/> to <paramref name="filePath"/> as UTF-8 without BOM.</summary>
+    public static Task WriteHtmlAsync(string filePath, string html, CancellationToken ct)
+        => File.WriteAllTextAsync(filePath, html, Utf8NoBom, ct);
+}
@@ -1,102 +1,50 @@
 using System.IO;
 using System.Text;
 using SharepointToolbox.Core.Models;
+using SharepointToolbox.Localization;
+using static SharepointToolbox.Services.Export.PermissionHtmlFragments;

 namespace SharepointToolbox.Services.Export;

 /// <summary>
 /// Exports permission entries to a self-contained interactive HTML report.
-/// Ports PowerShell Export-PermissionsToHTML functionality.
-/// No external CSS/JS dependencies — everything is inline.
+/// Ports PowerShell <c>Export-PermissionsToHTML</c> functionality.
+/// No external CSS/JS dependencies — everything is inline so the file can be
+/// emailed or served from any static host. The standard and simplified
+/// variants share their document shell, stats cards, CSS, pill rendering, and
+/// inline script via <see cref="PermissionHtmlFragments"/>; this class only
+/// owns the table column sets and the simplified risk summary.
 /// </summary>
 public class HtmlExportService
 {
    /// <summary>
-    /// Builds a self-contained HTML string from the supplied permission entries.
-    /// Includes inline CSS, inline JS filter, stats cards, type badges, unique/inherited badges, and user pills.
-    /// When <paramref name="groupMembers"/> is provided, SharePoint group pills become expandable.
+    /// Builds a self-contained HTML string from the supplied permission
+    /// entries. Standard report: columns are Object / Title / URL / Unique /
+    /// Users / Permission / Granted Through. When
+    /// <paramref name="groupMembers"/> is provided, SharePoint group pills
+    /// become expandable rows listing resolved members.
    /// </summary>
-    public string BuildHtml(IReadOnlyList<PermissionEntry> entries, ReportBranding? branding = null,
+    public string BuildHtml(
+        IReadOnlyList<PermissionEntry> entries,
+        ReportBranding? branding = null,
        IReadOnlyDictionary<string, IReadOnlyList<ResolvedMember>>? groupMembers = null)
    {
-        // Compute stats
-        var totalEntries      = entries.Count;
-        var uniquePermSets    = entries.Select(e => e.PermissionLevels).Distinct().Count();
-        var distinctUsers     = entries
-            .SelectMany(e => e.UserLogins.Split(';', StringSplitOptions.RemoveEmptyEntries))
-            .Select(u => u.Trim())
-            .Where(u => u.Length > 0)
-            .Distinct()
-            .Count();
+        var T = TranslationSource.Instance;
+        var (totalEntries, uniquePermSets, distinctUsers) = ComputeStats(
+            entries.Count,
+            entries.Select(e => e.PermissionLevels),
+            entries.SelectMany(e => e.UserLogins.Split(';', StringSplitOptions.RemoveEmptyEntries)));

        var sb = new StringBuilder();
-
-        // ── HTML HEAD ──────────────────────────────────────────────────────────
-        sb.AppendLine("<!DOCTYPE html>");
-        sb.AppendLine("<html lang=\"en\">");
-        sb.AppendLine("<head>");
-        sb.AppendLine("<meta charset=\"UTF-8\">");
-        sb.AppendLine("<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">");
-        sb.AppendLine("<title>SharePoint Permissions Report</title>");
-        sb.AppendLine("<style>");
-        sb.AppendLine(@"
-* { box-sizing: border-box; margin: 0; padding: 0; }
-body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; background: #f5f5f5; color: #333; }
-h1 { padding: 20px 24px 10px; font-size: 1.5rem; color: #1a1a2e; }
-.stats { display: flex; gap: 16px; padding: 0 24px 16px; flex-wrap: wrap; }
-.stat-card { background: #fff; border-radius: 8px; padding: 14px 20px; min-width: 160px; box-shadow: 0 1px 4px rgba(0,0,0,.1); }
-.stat-card .value { font-size: 2rem; font-weight: 700; color: #1a1a2e; }
-.stat-card .label { font-size: .8rem; color: #666; margin-top: 2px; }
-.filter-wrap { padding: 0 24px 12px; }
-#filter { width: 320px; padding: 8px 12px; border: 1px solid #ccc; border-radius: 6px; font-size: .95rem; }
-.table-wrap { overflow-x: auto; padding: 0 24px 32px; }
-table { width: 100%; border-collapse: collapse; background: #fff; border-radius: 8px; overflow: hidden; box-shadow: 0 1px 4px rgba(0,0,0,.1); }
-th { background: #1a1a2e; color: #fff; padding: 10px 14px; text-align: left; font-size: .85rem; white-space: nowrap; }
-td { padding: 9px 14px; border-bottom: 1px solid #eee; vertical-align: top; font-size: .875rem; }
-tr:last-child td { border-bottom: none; }
-tr:hover td { background: #fafafa; }
-/* Type badges */
-.badge { display: inline-block; padding: 2px 8px; border-radius: 4px; font-size: .75rem; font-weight: 600; white-space: nowrap; }
-.badge.site-coll { background: #dbeafe; color: #1e40af; }
-.badge.site      { background: #dcfce7; color: #166534; }
-.badge.list      { background: #fef9c3; color: #854d0e; }
-.badge.folder    { background: #f3f4f6; color: #374151; }
-/* Unique/Inherited badges */
-.badge.unique    { background: #dcfce7; color: #166534; }
-.badge.inherited { background: #f3f4f6; color: #374151; }
-/* User pills */
-.user-pill { display: inline-block; background: #e0e7ff; color: #3730a3; border-radius: 12px; padding: 2px 10px; font-size: .75rem; margin: 2px 3px 2px 0; white-space: nowrap; }
-.user-pill.external-user { background: #fff7ed; color: #9a3412; border: 1px solid #fed7aa; }
-.group-expandable { cursor: pointer; }
-.group-expandable:hover { opacity: 0.8; }
-a { color: #2563eb; text-decoration: none; }
-a:hover { text-decoration: underline; }
-");
-        sb.AppendLine("</style>");
-        sb.AppendLine("</head>");
-
-        // ── BODY ───────────────────────────────────────────────────────────────
+        AppendHead(sb, T["report.title.permissions"], includeRiskCss: false);
        sb.AppendLine("<body>");
        sb.Append(BrandingHtmlHelper.BuildBrandingHeader(branding));
-        sb.AppendLine("<h1>SharePoint Permissions Report</h1>");
-
-        // Stats cards
-        sb.AppendLine("<div class=\"stats\">");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{totalEntries}</div><div class=\"label\">Total Entries</div></div>");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{uniquePermSets}</div><div class=\"label\">Unique Permission Sets</div></div>");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{distinctUsers}</div><div class=\"label\">Distinct Users/Groups</div></div>");
-        sb.AppendLine("</div>");
-
-        // Filter input
-        sb.AppendLine("<div class=\"filter-wrap\">");
-        sb.AppendLine("  <input type=\"text\" id=\"filter\" placeholder=\"Filter permissions...\" onkeyup=\"filterTable()\" />");
-        sb.AppendLine("</div>");
-
-        // Table
-        sb.AppendLine("<div class=\"table-wrap\">");
-        sb.AppendLine("<table id=\"permTable\">");
+        sb.AppendLine($"<h1>{T["report.title.permissions"]}</h1>");
+        AppendStatsCards(sb, totalEntries, uniquePermSets, distinctUsers);
+        AppendFilterInput(sb);
+        AppendTableOpen(sb);
        sb.AppendLine("<thead><tr>");
-        sb.AppendLine("  <th>Object</th><th>Title</th><th>URL</th><th>Unique</th><th>Users/Groups</th><th>Permission Level</th><th>Granted Through</th>");
+        sb.AppendLine($"  <th>{T["report.col.object"]}</th><th>{T["report.col.title"]}</th><th>{T["report.col.url"]}</th><th>{T["report.badge.unique"]}</th><th>{T["report.col.users_groups"]}</th><th>{T["report.col.permission_level"]}</th><th>{T["report.col.granted_through"]}</th>");
        sb.AppendLine("</tr></thead>");
        sb.AppendLine("<tbody>");

@@ -105,99 +53,236 @@ a:hover { text-decoration: underline; }
        {
            var typeCss   = ObjectTypeCss(entry.ObjectType);
            var uniqueCss = entry.HasUniquePermissions ? "badge unique" : "badge inherited";
-            var uniqueLbl = entry.HasUniquePermissions ? "Unique" : "Inherited";
+            var uniqueLbl = entry.HasUniquePermissions ? T["report.badge.unique"] : T["report.badge.inherited"];

-            // Build user pills: zip UserLogins and Users (both semicolon-delimited)
-            var logins = entry.UserLogins.Split(';', StringSplitOptions.RemoveEmptyEntries);
-            var names  = entry.Users.Split(';', StringSplitOptions.RemoveEmptyEntries);
-            var pillsBuilder = new StringBuilder();
-            var memberSubRows = new StringBuilder();
-
-            for (int i = 0; i < logins.Length; i++)
-            {
-                var login = logins[i].Trim();
-                var name  = i < names.Length ? names[i].Trim() : login;
-                var isExt = login.Contains("#EXT#", StringComparison.OrdinalIgnoreCase);
-
-                bool isExpandableGroup = entry.PrincipalType == "SharePointGroup"
-                    && groupMembers != null
-                    && groupMembers.TryGetValue(name, out var members);
-
-                if (isExpandableGroup && groupMembers != null && groupMembers.TryGetValue(name, out var resolvedMembers))
-                {
-                    var grpId = $"grpmem{grpMemIdx}";
-                    pillsBuilder.Append($"<span class=\"user-pill group-expandable\" onclick=\"toggleGroup('{grpId}')\" data-email=\"{HtmlEncode(login)}\">{HtmlEncode(name)} &#9660;</span>");
-
-                    string memberContent;
-                    if (resolvedMembers.Count > 0)
-                    {
-                        var memberParts = resolvedMembers.Select(m => $"{HtmlEncode(m.DisplayName)} &lt;{HtmlEncode(m.Login)}&gt;");
-                        memberContent = string.Join(" &bull; ", memberParts);
-                    }
-                    else
-                    {
-                        memberContent = "<em style=\"color:#888\">members unavailable</em>";
-                    }
-                    memberSubRows.AppendLine($"<tr data-group=\"{grpId}\" style=\"display:none\"><td colspan=\"7\" style=\"padding-left:2em;font-size:.8rem;color:#555\">{memberContent}</td></tr>");
-                    grpMemIdx++;
-                }
-                else
-                {
-                    var pillCss = isExt ? "user-pill external-user" : "user-pill";
-                    pillsBuilder.Append($"<span class=\"{pillCss}\" data-email=\"{HtmlEncode(login)}\">{HtmlEncode(name)}</span>");
-                }
-            }
+            var (pills, subRows) = BuildUserPillsCell(
+                entry.UserLogins, entry.Users, entry.PrincipalType, groupMembers,
+                colSpan: 7, grpMemIdx: ref grpMemIdx);

            sb.AppendLine("<tr>");
            sb.AppendLine($"  <td><span class=\"{typeCss}\">{HtmlEncode(entry.ObjectType)}</span></td>");
            sb.AppendLine($"  <td>{HtmlEncode(entry.Title)}</td>");
-            sb.AppendLine($"  <td><a href=\"{HtmlEncode(entry.Url)}\" target=\"_blank\">Link</a></td>");
+            sb.AppendLine($"  <td><a href=\"{HtmlEncode(entry.Url)}\" target=\"_blank\">{T["report.text.link"]}</a></td>");
            sb.AppendLine($"  <td><span class=\"{uniqueCss}\">{uniqueLbl}</span></td>");
-            sb.AppendLine($"  <td>{pillsBuilder}</td>");
+            sb.AppendLine($"  <td>{pills}</td>");
            sb.AppendLine($"  <td>{HtmlEncode(entry.PermissionLevels)}</td>");
            sb.AppendLine($"  <td>{HtmlEncode(entry.GrantedThrough)}</td>");
            sb.AppendLine("</tr>");
-            if (memberSubRows.Length > 0)
-                sb.Append(memberSubRows);
+            if (subRows.Length > 0) sb.Append(subRows);
        }

-        sb.AppendLine("</tbody>");
-        sb.AppendLine("</table>");
-        sb.AppendLine("</div>");
-
-        // Inline JS
-        sb.AppendLine("<script>");
-        sb.AppendLine(@"function filterTable() {
-  var input = document.getElementById('filter').value.toLowerCase();
-  var rows = document.querySelectorAll('#permTable tbody tr');
-  rows.forEach(function(row) {
-    if (row.hasAttribute('data-group')) return;
-    row.style.display = row.textContent.toLowerCase().indexOf(input) > -1 ? '' : 'none';
-  });
-}
-function toggleGroup(id) {
-  var rows = document.querySelectorAll('tr[data-group=""' + id + '""]');
-  rows.forEach(function(r) { r.style.display = r.style.display === 'none' ? '' : 'none'; });
-}");
-        sb.AppendLine("</script>");
+        AppendTableClose(sb);
+        AppendInlineJs(sb);
        sb.AppendLine("</body>");
        sb.AppendLine("</html>");
-
        return sb.ToString();
    }

    /// <summary>
-    /// Writes the HTML report to the specified file path using UTF-8 without BOM.
+    /// Builds a self-contained HTML string from simplified permission entries.
+    /// Adds a risk-level summary card strip plus two columns (Simplified,
+    /// Risk) relative to <see cref="BuildHtml(IReadOnlyList{PermissionEntry}, ReportBranding?, IReadOnlyDictionary{string, IReadOnlyList{ResolvedMember}}?)"/>.
+    /// Color-coded risk badges use <see cref="RiskLevelColors(RiskLevel)"/>.
    /// </summary>
-    public async Task WriteAsync(IReadOnlyList<PermissionEntry> entries, string filePath, CancellationToken ct,
+    public string BuildHtml(
+        IReadOnlyList<SimplifiedPermissionEntry> entries,
+        ReportBranding? branding = null,
+        IReadOnlyDictionary<string, IReadOnlyList<ResolvedMember>>? groupMembers = null)
+    {
+        var T = TranslationSource.Instance;
+        var summaries = PermissionSummaryBuilder.Build(entries);
+        var (totalEntries, uniquePermSets, distinctUsers) = ComputeStats(
+            entries.Count,
+            entries.Select(e => e.PermissionLevels),
+            entries.SelectMany(e => e.UserLogins.Split(';', StringSplitOptions.RemoveEmptyEntries)));
+
+        var sb = new StringBuilder();
+        AppendHead(sb, T["report.title.permissions_simplified"], includeRiskCss: true);
+        sb.AppendLine("<body>");
+        sb.Append(BrandingHtmlHelper.BuildBrandingHeader(branding));
+        sb.AppendLine($"<h1>{T["report.title.permissions_simplified"]}</h1>");
+        AppendStatsCards(sb, totalEntries, uniquePermSets, distinctUsers);
+
+        sb.AppendLine("<div class=\"risk-cards\">");
+        foreach (var s in summaries)
+        {
+            var (bg, text, border) = RiskLevelColors(s.RiskLevel);
+            sb.AppendLine($"  <div class=\"risk-card\" style=\"background:{bg};color:{text};border-color:{border}\">");
+            sb.AppendLine($"    <div class=\"count\">{s.Count}</div>");
+            sb.AppendLine($"    <div class=\"rlabel\">{HtmlEncode(s.Label)}</div>");
+            sb.AppendLine($"    <div class=\"users\">{s.DistinctUsers} {T["report.text.users_parens"]}</div>");
+            sb.AppendLine("  </div>");
+        }
+        sb.AppendLine("</div>");
+
+        AppendFilterInput(sb);
+        AppendTableOpen(sb);
+        sb.AppendLine("<thead><tr>");
+        sb.AppendLine($"  <th>{T["report.col.object"]}</th><th>{T["report.col.title"]}</th><th>{T["report.col.url"]}</th><th>{T["report.badge.unique"]}</th><th>{T["report.col.users_groups"]}</th><th>{T["report.col.permission_level"]}</th><th>{T["report.col.simplified"]}</th><th>{T["report.col.risk"]}</th><th>{T["report.col.granted_through"]}</th>");
+        sb.AppendLine("</tr></thead>");
+        sb.AppendLine("<tbody>");
+
+        int grpMemIdx = 0;
+        foreach (var entry in entries)
+        {
+            var typeCss   = ObjectTypeCss(entry.ObjectType);
+            var uniqueCss = entry.HasUniquePermissions ? "badge unique" : "badge inherited";
+            var uniqueLbl = entry.HasUniquePermissions ? T["report.badge.unique"] : T["report.badge.inherited"];
+            var (riskBg, riskText, riskBorder) = RiskLevelColors(entry.RiskLevel);
+
+            var (pills, subRows) = BuildUserPillsCell(
+                entry.UserLogins, entry.Inner.Users, entry.Inner.PrincipalType, groupMembers,
+                colSpan: 9, grpMemIdx: ref grpMemIdx);
+
+            sb.AppendLine("<tr>");
+            sb.AppendLine($"  <td><span class=\"{typeCss}\">{HtmlEncode(entry.ObjectType)}</span></td>");
+            sb.AppendLine($"  <td>{HtmlEncode(entry.Title)}</td>");
+            sb.AppendLine($"  <td><a href=\"{HtmlEncode(entry.Url)}\" target=\"_blank\">{T["report.text.link"]}</a></td>");
+            sb.AppendLine($"  <td><span class=\"{uniqueCss}\">{uniqueLbl}</span></td>");
+            sb.AppendLine($"  <td>{pills}</td>");
+            sb.AppendLine($"  <td>{HtmlEncode(entry.PermissionLevels)}</td>");
+            sb.AppendLine($"  <td>{HtmlEncode(entry.SimplifiedLabels)}</td>");
+            sb.AppendLine($"  <td><span class=\"risk-badge\" style=\"background:{riskBg};color:{riskText};border-color:{riskBorder}\">{HtmlEncode(entry.RiskLevel.ToString())}</span></td>");
+            sb.AppendLine($"  <td>{HtmlEncode(entry.GrantedThrough)}</td>");
+            sb.AppendLine("</tr>");
+            if (subRows.Length > 0) sb.Append(subRows);
+        }
+
+        AppendTableClose(sb);
+        AppendInlineJs(sb);
+        sb.AppendLine("</body>");
+        sb.AppendLine("</html>");
+        return sb.ToString();
+    }
+
+    /// <summary>Writes the HTML report to the specified file path using UTF-8 without BOM.</summary>
+    public async Task WriteAsync(
+        IReadOnlyList<PermissionEntry> entries,
+        string filePath,
+        CancellationToken ct,
        ReportBranding? branding = null,
        IReadOnlyDictionary<string, IReadOnlyList<ResolvedMember>>? groupMembers = null)
    {
        var html = BuildHtml(entries, branding, groupMembers);
-        await File.WriteAllTextAsync(filePath, html, new UTF8Encoding(encoderShouldEmitUTF8Identifier: false), ct);
+        await ExportFileWriter.WriteHtmlAsync(filePath, html, ct);
    }

-    /// <summary>Returns inline CSS background and text color for a risk level.</summary>
+    /// <summary>Writes the simplified HTML report to the specified file path using UTF-8 without BOM.</summary>
+    public async Task WriteAsync(
+        IReadOnlyList<SimplifiedPermissionEntry> entries,
+        string filePath,
+        CancellationToken ct,
+        ReportBranding? branding = null,
+        IReadOnlyDictionary<string, IReadOnlyList<ResolvedMember>>? groupMembers = null)
+    {
+        var html = BuildHtml(entries, branding, groupMembers);
+        await ExportFileWriter.WriteHtmlAsync(filePath, html, ct);
+    }
+
+    /// <summary>
+    /// Split-aware write for permission entries.
+    /// Single → one file. BySite + SeparateFiles → one file per site.
+    /// BySite + SingleTabbed → one file with per-site iframe tabs.
+    /// </summary>
+    public async Task WriteAsync(
+        IReadOnlyList<PermissionEntry> entries,
+        string basePath,
+        ReportSplitMode splitMode,
+        HtmlSplitLayout layout,
+        CancellationToken ct,
+        ReportBranding? branding = null,
+        IReadOnlyDictionary<string, IReadOnlyList<ResolvedMember>>? groupMembers = null)
+    {
+        if (splitMode != ReportSplitMode.BySite)
+        {
+            await WriteAsync(entries, basePath, ct, branding, groupMembers);
+            return;
+        }
+
+        var partitions = CsvExportService.PartitionBySite(entries).ToList();
+        if (layout == HtmlSplitLayout.SingleTabbed)
+        {
+            var parts = partitions
+                .Select(p => (p.Label, Html: BuildHtml(p.Partition, branding, groupMembers)))
+                .ToList();
+            var title = TranslationSource.Instance["report.title.permissions"];
+            var tabbed = ReportSplitHelper.BuildTabbedHtml(parts, title);
+            await ExportFileWriter.WriteHtmlAsync(basePath, tabbed, ct);
+            return;
+        }
+
+        foreach (var (label, partEntries) in partitions)
+        {
+            ct.ThrowIfCancellationRequested();
+            var path = ReportSplitHelper.BuildPartitionPath(basePath, label);
+            await WriteAsync(partEntries, path, ct, branding, groupMembers);
+        }
+    }
+
+    /// <summary>Simplified-entry split variant of <see cref="WriteAsync(IReadOnlyList{PermissionEntry}, string, ReportSplitMode, HtmlSplitLayout, CancellationToken, ReportBranding?, IReadOnlyDictionary{string, IReadOnlyList{ResolvedMember}}?)"/>.</summary>
+    public async Task WriteAsync(
+        IReadOnlyList<SimplifiedPermissionEntry> entries,
+        string basePath,
+        ReportSplitMode splitMode,
+        HtmlSplitLayout layout,
+        CancellationToken ct,
+        ReportBranding? branding = null,
+        IReadOnlyDictionary<string, IReadOnlyList<ResolvedMember>>? groupMembers = null)
+    {
+        if (splitMode != ReportSplitMode.BySite)
+        {
+            await WriteAsync(entries, basePath, ct, branding, groupMembers);
+            return;
+        }
+
+        var partitions = CsvExportService.PartitionBySite(entries).ToList();
+        if (layout == HtmlSplitLayout.SingleTabbed)
+        {
+            var parts = partitions
+                .Select(p => (p.Label, Html: BuildHtml(p.Partition, branding, groupMembers)))
+                .ToList();
+            var title = TranslationSource.Instance["report.title.permissions_simplified"];
+            var tabbed = ReportSplitHelper.BuildTabbedHtml(parts, title);
+            await ExportFileWriter.WriteHtmlAsync(basePath, tabbed, ct);
+            return;
+        }
+
+        foreach (var (label, partEntries) in partitions)
+        {
+            ct.ThrowIfCancellationRequested();
+            var path = ReportSplitHelper.BuildPartitionPath(basePath, label);
+            await WriteAsync(partEntries, path, ct, branding, groupMembers);
+        }
+    }
+
+    private static (int total, int uniquePerms, int distinctUsers) ComputeStats(
+        int totalEntries,
+        IEnumerable<string> permissionLevels,
+        IEnumerable<string> userLogins)
+    {
+        var uniquePermSets = permissionLevels.Distinct().Count();
+        var distinctUsers = userLogins
+            .Select(u => u.Trim())
+            .Where(u => u.Length > 0)
+            .Distinct()
+            .Count();
+        return (totalEntries, uniquePermSets, distinctUsers);
+    }
+
+    private static void AppendTableOpen(StringBuilder sb)
+    {
+        sb.AppendLine("<div class=\"table-wrap\">");
+        sb.AppendLine("<table id=\"permTable\">");
+    }
+
+    private static void AppendTableClose(StringBuilder sb)
+    {
+        sb.AppendLine("</tbody>");
+        sb.AppendLine("</table>");
+        sb.AppendLine("</div>");
+    }
+
+    /// <summary>Returns inline CSS background, text, and border colors for a risk level.</summary>
    private static (string bg, string text, string border) RiskLevelColors(RiskLevel level) => level switch
    {
        RiskLevel.High     => ("#FEE2E2", "#991B1B", "#FECACA"),
@@ -206,228 +291,4 @@ function toggleGroup(id) {
        RiskLevel.ReadOnly => ("#DBEAFE", "#1E40AF", "#BFDBFE"),
        _                  => ("#F3F4F6", "#374151", "#E5E7EB")
    };
-
-    /// <summary>
-    /// Builds a self-contained HTML string from simplified permission entries.
-    /// Includes risk-level summary cards, color-coded rows, and simplified labels column.
-    /// When <paramref name="groupMembers"/> is provided, SharePoint group pills become expandable.
-    /// </summary>
-    public string BuildHtml(IReadOnlyList<SimplifiedPermissionEntry> entries, ReportBranding? branding = null,
-        IReadOnlyDictionary<string, IReadOnlyList<ResolvedMember>>? groupMembers = null)
-    {
-        var summaries = PermissionSummaryBuilder.Build(entries);
-
-        var totalEntries   = entries.Count;
-        var uniquePermSets = entries.Select(e => e.PermissionLevels).Distinct().Count();
-        var distinctUsers  = entries
-            .SelectMany(e => e.UserLogins.Split(';', StringSplitOptions.RemoveEmptyEntries))
-            .Select(u => u.Trim())
-            .Where(u => u.Length > 0)
-            .Distinct()
-            .Count();
-
-        var sb = new StringBuilder();
-
-        sb.AppendLine("<!DOCTYPE html>");
-        sb.AppendLine("<html lang=\"en\">");
-        sb.AppendLine("<head>");
-        sb.AppendLine("<meta charset=\"UTF-8\">");
-        sb.AppendLine("<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">");
-        sb.AppendLine("<title>SharePoint Permissions Report (Simplified)</title>");
-        sb.AppendLine("<style>");
-        sb.AppendLine(@"
-    * { box-sizing: border-box; margin: 0; padding: 0; }
-    body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; background: #f5f5f5; color: #333; }
-    h1 { padding: 20px 24px 10px; font-size: 1.5rem; color: #1a1a2e; }
-    .stats { display: flex; gap: 16px; padding: 0 24px 16px; flex-wrap: wrap; }
-    .stat-card { background: #fff; border-radius: 8px; padding: 14px 20px; min-width: 160px; box-shadow: 0 1px 4px rgba(0,0,0,.1); }
-    .stat-card .value { font-size: 2rem; font-weight: 700; color: #1a1a2e; }
-    .stat-card .label { font-size: .8rem; color: #666; margin-top: 2px; }
-    .risk-cards { display: flex; gap: 12px; padding: 0 24px 16px; flex-wrap: wrap; }
-    .risk-card { border-radius: 8px; padding: 12px 18px; min-width: 140px; border: 1px solid; }
-    .risk-card .count { font-size: 1.5rem; font-weight: 700; }
-    .risk-card .rlabel { font-size: .8rem; margin-top: 2px; }
-    .risk-card .users { font-size: .7rem; margin-top: 2px; opacity: 0.8; }
-    .filter-wrap { padding: 0 24px 12px; }
-    #filter { width: 320px; padding: 8px 12px; border: 1px solid #ccc; border-radius: 6px; font-size: .95rem; }
-    .table-wrap { overflow-x: auto; padding: 0 24px 32px; }
-    table { width: 100%; border-collapse: collapse; background: #fff; border-radius: 8px; overflow: hidden; box-shadow: 0 1px 4px rgba(0,0,0,.1); }
-    th { background: #1a1a2e; color: #fff; padding: 10px 14px; text-align: left; font-size: .85rem; white-space: nowrap; }
-    td { padding: 9px 14px; border-bottom: 1px solid #eee; vertical-align: top; font-size: .875rem; }
-    tr:last-child td { border-bottom: none; }
-    tr:hover td { background: rgba(0,0,0,.03); }
-    .badge { display: inline-block; padding: 2px 8px; border-radius: 4px; font-size: .75rem; font-weight: 600; white-space: nowrap; }
-    .badge.site-coll { background: #dbeafe; color: #1e40af; }
-    .badge.site      { background: #dcfce7; color: #166534; }
-    .badge.list      { background: #fef9c3; color: #854d0e; }
-    .badge.folder    { background: #f3f4f6; color: #374151; }
-    .badge.unique    { background: #dcfce7; color: #166534; }
-    .badge.inherited { background: #f3f4f6; color: #374151; }
-    .risk-badge { display: inline-block; padding: 2px 8px; border-radius: 4px; font-size: .75rem; font-weight: 600; border: 1px solid; }
-    .user-pill { display: inline-block; background: #e0e7ff; color: #3730a3; border-radius: 12px; padding: 2px 10px; font-size: .75rem; margin: 2px 3px 2px 0; white-space: nowrap; }
-    .user-pill.external-user { background: #fff7ed; color: #9a3412; border: 1px solid #fed7aa; }
-    .group-expandable { cursor: pointer; }
-    .group-expandable:hover { opacity: 0.8; }
-    a { color: #2563eb; text-decoration: none; }
-    a:hover { text-decoration: underline; }
-    ");
-        sb.AppendLine("</style>");
-        sb.AppendLine("</head>");
-
-        sb.AppendLine("<body>");
-        sb.Append(BrandingHtmlHelper.BuildBrandingHeader(branding));
-        sb.AppendLine("<h1>SharePoint Permissions Report (Simplified)</h1>");
-
-        // Stats cards
-        sb.AppendLine("<div class=\"stats\">");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{totalEntries}</div><div class=\"label\">Total Entries</div></div>");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{uniquePermSets}</div><div class=\"label\">Unique Permission Sets</div></div>");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{distinctUsers}</div><div class=\"label\">Distinct Users/Groups</div></div>");
-        sb.AppendLine("</div>");
-
-        // Risk-level summary cards
-        sb.AppendLine("<div class=\"risk-cards\">");
-        foreach (var summary in summaries)
-        {
-            var (bg, text, border) = RiskLevelColors(summary.RiskLevel);
-            sb.AppendLine($"  <div class=\"risk-card\" style=\"background:{bg};color:{text};border-color:{border}\">");
-            sb.AppendLine($"    <div class=\"count\">{summary.Count}</div>");
-            sb.AppendLine($"    <div class=\"rlabel\">{HtmlEncode(summary.Label)}</div>");
-            sb.AppendLine($"    <div class=\"users\">{summary.DistinctUsers} user(s)</div>");
-            sb.AppendLine("  </div>");
-        }
-        sb.AppendLine("</div>");
-
-        // Filter input
-        sb.AppendLine("<div class=\"filter-wrap\">");
-        sb.AppendLine("  <input type=\"text\" id=\"filter\" placeholder=\"Filter permissions...\" onkeyup=\"filterTable()\" />");
-        sb.AppendLine("</div>");
-
-        // Table with simplified columns
-        sb.AppendLine("<div class=\"table-wrap\">");
-        sb.AppendLine("<table id=\"permTable\">");
-        sb.AppendLine("<thead><tr>");
-        sb.AppendLine("  <th>Object</th><th>Title</th><th>URL</th><th>Unique</th><th>Users/Groups</th><th>Permission Level</th><th>Simplified</th><th>Risk</th><th>Granted Through</th>");
-        sb.AppendLine("</tr></thead>");
-        sb.AppendLine("<tbody>");
-
-        int grpMemIdx = 0;
-        foreach (var entry in entries)
-        {
-            var typeCss   = ObjectTypeCss(entry.ObjectType);
-            var uniqueCss = entry.HasUniquePermissions ? "badge unique" : "badge inherited";
-            var uniqueLbl = entry.HasUniquePermissions ? "Unique" : "Inherited";
-            var (riskBg, riskText, riskBorder) = RiskLevelColors(entry.RiskLevel);
-
-            var logins = entry.UserLogins.Split(';', StringSplitOptions.RemoveEmptyEntries);
-            var names  = entry.Inner.Users.Split(';', StringSplitOptions.RemoveEmptyEntries);
-            var pillsBuilder = new StringBuilder();
-            var memberSubRows = new StringBuilder();
-
-            for (int i = 0; i < logins.Length; i++)
-            {
-                var login = logins[i].Trim();
-                var name  = i < names.Length ? names[i].Trim() : login;
-                var isExt = login.Contains("#EXT#", StringComparison.OrdinalIgnoreCase);
-
-                bool isExpandableGroup = entry.Inner.PrincipalType == "SharePointGroup"
-                    && groupMembers != null
-                    && groupMembers.TryGetValue(name, out _);
-
-                if (isExpandableGroup && groupMembers != null && groupMembers.TryGetValue(name, out var resolvedMembers))
-                {
-                    var grpId = $"grpmem{grpMemIdx}";
-                    pillsBuilder.Append($"<span class=\"user-pill group-expandable\" onclick=\"toggleGroup('{grpId}')\" data-email=\"{HtmlEncode(login)}\">{HtmlEncode(name)} &#9660;</span>");
-
-                    string memberContent;
-                    if (resolvedMembers.Count > 0)
-                    {
-                        var memberParts = resolvedMembers.Select(m => $"{HtmlEncode(m.DisplayName)} &lt;{HtmlEncode(m.Login)}&gt;");
-                        memberContent = string.Join(" &bull; ", memberParts);
-                    }
-                    else
-                    {
-                        memberContent = "<em style=\"color:#888\">members unavailable</em>";
-                    }
-                    memberSubRows.AppendLine($"<tr data-group=\"{grpId}\" style=\"display:none\"><td colspan=\"9\" style=\"padding-left:2em;font-size:.8rem;color:#555\">{memberContent}</td></tr>");
-                    grpMemIdx++;
-                }
-                else
-                {
-                    var pillCss = isExt ? "user-pill external-user" : "user-pill";
-                    pillsBuilder.Append($"<span class=\"{pillCss}\" data-email=\"{HtmlEncode(login)}\">{HtmlEncode(name)}</span>");
-                }
-            }
-
-            sb.AppendLine("<tr>");
-            sb.AppendLine($"  <td><span class=\"{typeCss}\">{HtmlEncode(entry.ObjectType)}</span></td>");
-            sb.AppendLine($"  <td>{HtmlEncode(entry.Title)}</td>");
-            sb.AppendLine($"  <td><a href=\"{HtmlEncode(entry.Url)}\" target=\"_blank\">Link</a></td>");
-            sb.AppendLine($"  <td><span class=\"{uniqueCss}\">{uniqueLbl}</span></td>");
-            sb.AppendLine($"  <td>{pillsBuilder}</td>");
-            sb.AppendLine($"  <td>{HtmlEncode(entry.PermissionLevels)}</td>");
-            sb.AppendLine($"  <td>{HtmlEncode(entry.SimplifiedLabels)}</td>");
-            sb.AppendLine($"  <td><span class=\"risk-badge\" style=\"background:{riskBg};color:{riskText};border-color:{riskBorder}\">{HtmlEncode(entry.RiskLevel.ToString())}</span></td>");
-            sb.AppendLine($"  <td>{HtmlEncode(entry.GrantedThrough)}</td>");
-            sb.AppendLine("</tr>");
-            if (memberSubRows.Length > 0)
-                sb.Append(memberSubRows);
-        }
-
-        sb.AppendLine("</tbody>");
-        sb.AppendLine("</table>");
-        sb.AppendLine("</div>");
-
-        sb.AppendLine("<script>");
-        sb.AppendLine(@"function filterTable() {
-      var input = document.getElementById('filter').value.toLowerCase();
-      var rows = document.querySelectorAll('#permTable tbody tr');
-      rows.forEach(function(row) {
-        if (row.hasAttribute('data-group')) return;
-        row.style.display = row.textContent.toLowerCase().indexOf(input) > -1 ? '' : 'none';
-      });
-    }
-    function toggleGroup(id) {
-      var rows = document.querySelectorAll('tr[data-group=""' + id + '""]');
-      rows.forEach(function(r) { r.style.display = r.style.display === 'none' ? '' : 'none'; });
-    }");
-        sb.AppendLine("</script>");
-        sb.AppendLine("</body>");
-        sb.AppendLine("</html>");
-
-        return sb.ToString();
-    }
-
-    /// <summary>
-    /// Writes the simplified HTML report to the specified file path.
-    /// </summary>
-    public async Task WriteAsync(IReadOnlyList<SimplifiedPermissionEntry> entries, string filePath, CancellationToken ct,
-        ReportBranding? branding = null,
-        IReadOnlyDictionary<string, IReadOnlyList<ResolvedMember>>? groupMembers = null)
-    {
-        var html = BuildHtml(entries, branding, groupMembers);
-        await File.WriteAllTextAsync(filePath, html, new UTF8Encoding(encoderShouldEmitUTF8Identifier: false), ct);
-    }
-
-    /// <summary>Returns the CSS class for the object-type badge.</summary>
-    private static string ObjectTypeCss(string t) => t switch
-    {
-        "Site Collection" => "badge site-coll",
-        "Site"            => "badge site",
-        "List"            => "badge list",
-        "Folder"          => "badge folder",
-        _                 => "badge"
-    };
-
-    /// <summary>Minimal HTML encoding for text content and attribute values.</summary>
-    private static string HtmlEncode(string value)
-    {
-        if (string.IsNullOrEmpty(value)) return string.Empty;
-        return value
-            .Replace("&",  "&amp;")
-            .Replace("<",  "&lt;")
-            .Replace(">",  "&gt;")
-            .Replace("\"", "&quot;")
-            .Replace("'",  "&#39;");
-    }
 }
@@ -0,0 +1,207 @@
+using System.Text;
+using SharepointToolbox.Core.Models;
+using SharepointToolbox.Localization;
+
+namespace SharepointToolbox.Services.Export;
+
+/// <summary>
+/// Shared HTML-rendering fragments for the permission exports (standard and
+/// simplified). Extracted so the two <see cref="HtmlExportService"/> variants
+/// share the document shell, stats cards, filter input, user-pill logic, and
+/// inline script — leaving each caller only its own table headers and row
+/// cells to render.
+/// </summary>
+internal static class PermissionHtmlFragments
+{
+    internal const string BaseCss = @"
+* { box-sizing: border-box; margin: 0; padding: 0; }
+body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif; background: #f5f5f5; color: #333; }
+h1 { padding: 20px 24px 10px; font-size: 1.5rem; color: #1a1a2e; }
+.stats { display: flex; gap: 16px; padding: 0 24px 16px; flex-wrap: wrap; }
+.stat-card { background: #fff; border-radius: 8px; padding: 14px 20px; min-width: 160px; box-shadow: 0 1px 4px rgba(0,0,0,.1); }
+.stat-card .value { font-size: 2rem; font-weight: 700; color: #1a1a2e; }
+.stat-card .label { font-size: .8rem; color: #666; margin-top: 2px; }
+.filter-wrap { padding: 0 24px 12px; }
+#filter { width: 320px; padding: 8px 12px; border: 1px solid #ccc; border-radius: 6px; font-size: .95rem; }
+.table-wrap { overflow-x: auto; padding: 0 24px 32px; }
+table { width: 100%; border-collapse: collapse; background: #fff; border-radius: 8px; overflow: hidden; box-shadow: 0 1px 4px rgba(0,0,0,.1); }
+th { background: #1a1a2e; color: #fff; padding: 10px 14px; text-align: left; font-size: .85rem; white-space: nowrap; }
+td { padding: 9px 14px; border-bottom: 1px solid #eee; vertical-align: top; font-size: .875rem; }
+tr:last-child td { border-bottom: none; }
+tr:hover td { background: #fafafa; }
+.badge { display: inline-block; padding: 2px 8px; border-radius: 4px; font-size: .75rem; font-weight: 600; white-space: nowrap; }
+.badge.site-coll { background: #dbeafe; color: #1e40af; }
+.badge.site      { background: #dcfce7; color: #166534; }
+.badge.list      { background: #fef9c3; color: #854d0e; }
+.badge.folder    { background: #f3f4f6; color: #374151; }
+.badge.unique    { background: #dcfce7; color: #166534; }
+.badge.inherited { background: #f3f4f6; color: #374151; }
+.user-pill { display: inline-block; background: #e0e7ff; color: #3730a3; border-radius: 12px; padding: 2px 10px; font-size: .75rem; margin: 2px 3px 2px 0; white-space: nowrap; }
+.user-pill.external-user { background: #fff7ed; color: #9a3412; border: 1px solid #fed7aa; }
+.group-expandable { cursor: pointer; }
+.group-expandable:hover { opacity: 0.8; }
+a { color: #2563eb; text-decoration: none; }
+a:hover { text-decoration: underline; }
+";
+
+    internal const string RiskCardsCss = @"
+.risk-cards { display: flex; gap: 12px; padding: 0 24px 16px; flex-wrap: wrap; }
+.risk-card { border-radius: 8px; padding: 12px 18px; min-width: 140px; border: 1px solid; }
+.risk-card .count { font-size: 1.5rem; font-weight: 700; }
+.risk-card .rlabel { font-size: .8rem; margin-top: 2px; }
+.risk-card .users { font-size: .7rem; margin-top: 2px; opacity: 0.8; }
+.risk-badge { display: inline-block; padding: 2px 8px; border-radius: 4px; font-size: .75rem; font-weight: 600; border: 1px solid; }
+";
+
+    internal const string InlineJs = @"function filterTable() {
+  var input = document.getElementById('filter').value.toLowerCase();
+  var rows = document.querySelectorAll('#permTable tbody tr');
+  rows.forEach(function(row) {
+    if (row.hasAttribute('data-group')) return;
+    row.style.display = row.textContent.toLowerCase().indexOf(input) > -1 ? '' : 'none';
+  });
+}
+document.addEventListener('click', function(ev) {
+  var trigger = ev.target.closest('.group-expandable');
+  if (!trigger) return;
+  var id = trigger.getAttribute('data-group-target');
+  if (!id) return;
+  document.querySelectorAll('#permTable tbody tr').forEach(function(r) {
+    if (r.getAttribute('data-group') === id) {
+      r.style.display = r.style.display === 'none' ? '' : 'none';
+    }
+  });
+});";
+
+    /// <summary>
+    /// Appends the shared HTML head (doctype, meta, inline CSS, title) to
+    /// <paramref name="sb"/>. Pass <paramref name="includeRiskCss"/> when the
+    /// caller renders risk cards/badges (simplified report only).
+    /// </summary>
+    internal static void AppendHead(StringBuilder sb, string title, bool includeRiskCss)
+    {
+        sb.AppendLine("<!DOCTYPE html>");
+        sb.AppendLine("<html lang=\"en\">");
+        sb.AppendLine("<head>");
+        sb.AppendLine("<meta charset=\"UTF-8\">");
+        sb.AppendLine("<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">");
+        sb.AppendLine($"<title>{title}</title>");
+        sb.AppendLine("<style>");
+        sb.AppendLine(BaseCss);
+        if (includeRiskCss)
+            sb.AppendLine(RiskCardsCss);
+        sb.AppendLine("</style>");
+        sb.AppendLine("</head>");
+    }
+
+    /// <summary>
+    /// Appends the three stat cards (total entries, unique permission sets,
+    /// distinct users/groups) inside a single <c>.stats</c> row.
+    /// </summary>
+    internal static void AppendStatsCards(StringBuilder sb, int totalEntries, int uniquePermSets, int distinctUsers)
+    {
+        var T = TranslationSource.Instance;
+        sb.AppendLine("<div class=\"stats\">");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{totalEntries}</div><div class=\"label\">{T["report.stat.total_entries"]}</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{uniquePermSets}</div><div class=\"label\">{T["report.stat.unique_permission_sets"]}</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{distinctUsers}</div><div class=\"label\">{T["report.stat.distinct_users_groups"]}</div></div>");
+        sb.AppendLine("</div>");
+    }
+
+    /// <summary>Appends the live-filter input bound to <c>#permTable</c>.</summary>
+    internal static void AppendFilterInput(StringBuilder sb)
+    {
+        var T = TranslationSource.Instance;
+        sb.AppendLine("<div class=\"filter-wrap\">");
+        sb.AppendLine($"  <input type=\"text\" id=\"filter\" placeholder=\"{T["report.filter.placeholder_permissions"]}\" onkeyup=\"filterTable()\" />");
+        sb.AppendLine("</div>");
+    }
+
+    /// <summary>Appends the inline &lt;script&gt; that powers filter and group toggle.</summary>
+    internal static void AppendInlineJs(StringBuilder sb)
+    {
+        sb.AppendLine("<script>");
+        sb.AppendLine(InlineJs);
+        sb.AppendLine("</script>");
+    }
+
+    /// <summary>
+    /// Renders the user-pill cell content plus any group-member sub-rows for a
+    /// single permission entry. Callers pass their row colspan so sub-rows
+    /// span the full table; <paramref name="grpMemIdx"/> must be mutated
+    /// across rows so sub-row IDs stay unique.
+    /// </summary>
+    internal static (string Pills, string MemberSubRows) BuildUserPillsCell(
+        string userLogins,
+        string userNames,
+        string? principalType,
+        IReadOnlyDictionary<string, IReadOnlyList<ResolvedMember>>? groupMembers,
+        int colSpan,
+        ref int grpMemIdx)
+    {
+        var T = TranslationSource.Instance;
+        var logins = userLogins.Split(';', StringSplitOptions.RemoveEmptyEntries);
+        var names  = userNames.Split(';', StringSplitOptions.RemoveEmptyEntries);
+        var pills = new StringBuilder();
+        var subRows = new StringBuilder();
+
+        for (int i = 0; i < logins.Length; i++)
+        {
+            var login = logins[i].Trim();
+            var name  = i < names.Length ? names[i].Trim() : login;
+            var isExt = login.Contains("#EXT#", StringComparison.OrdinalIgnoreCase);
+
+            bool isExpandable = principalType == "SharePointGroup"
+                && groupMembers != null
+                && groupMembers.TryGetValue(name, out _);
+
+            if (isExpandable && groupMembers != null && groupMembers.TryGetValue(name, out var resolved))
+            {
+                var grpId = $"grpmem{grpMemIdx}";
+                pills.Append($"<span class=\"user-pill group-expandable\" data-group-target=\"{HtmlEncode(grpId)}\" data-email=\"{HtmlEncode(login)}\">{HtmlEncode(name)} &#9660;</span>");
+
+                string memberContent;
+                if (resolved.Count > 0)
+                {
+                    var parts = resolved.Select(m => $"{HtmlEncode(m.DisplayName)} &lt;{HtmlEncode(m.Login)}&gt;");
+                    memberContent = string.Join(" &bull; ", parts);
+                }
+                else
+                {
+                    memberContent = $"<em style=\"color:#888\">{T["report.text.members_unavailable"]}</em>";
+                }
+                subRows.AppendLine($"<tr data-group=\"{HtmlEncode(grpId)}\" style=\"display:none\"><td colspan=\"{colSpan}\" style=\"padding-left:2em;font-size:.8rem;color:#555\">{memberContent}</td></tr>");
+                grpMemIdx++;
+            }
+            else
+            {
+                var cls = isExt ? "user-pill external-user" : "user-pill";
+                pills.Append($"<span class=\"{cls}\" data-email=\"{HtmlEncode(login)}\">{HtmlEncode(name)}</span>");
+            }
+        }
+
+        return (pills.ToString(), subRows.ToString());
+    }
+
+    /// <summary>Returns the CSS class for the object-type badge.</summary>
+    internal static string ObjectTypeCss(string t) => t switch
+    {
+        "Site Collection" => "badge site-coll",
+        "Site"            => "badge site",
+        "List"            => "badge list",
+        "Folder"          => "badge folder",
+        _                 => "badge"
+    };
+
+    /// <summary>Minimal HTML encoding for text content and attribute values.</summary>
+    internal static string HtmlEncode(string value)
+    {
+        if (string.IsNullOrEmpty(value)) return string.Empty;
+        return value
+            .Replace("&",  "&amp;")
+            .Replace("<",  "&lt;")
+            .Replace(">",  "&gt;")
+            .Replace("\"", "&quot;")
+            .Replace("'",  "&#39;");
+    }
+}
@@ -0,0 +1,199 @@
+using System.Diagnostics;
+using System.IO;
+using System.Net;
+using System.Text;
+
+namespace SharepointToolbox.Services.Export;
+
+/// <summary>
+/// Shared helpers for split report exports: filename partitioning, site label
+/// derivation, and bundling per-partition HTML into a single tabbed document.
+/// </summary>
+public static class ReportSplitHelper
+{
+    /// <summary>
+    /// Returns a file-safe variant of <paramref name="name"/>. Invalid filename
+    /// characters are replaced with underscores; whitespace runs are collapsed.
+    /// </summary>
+    public static string SanitizeFileName(string name)
+    {
+        if (string.IsNullOrWhiteSpace(name)) return "part";
+        var invalid = Path.GetInvalidFileNameChars();
+        var sb = new StringBuilder(name.Length);
+        foreach (var c in name)
+            sb.Append(invalid.Contains(c) || c == ' ' ? '_' : c);
+        var trimmed = sb.ToString().Trim('_');
+        if (trimmed.Length > 80) trimmed = trimmed.Substring(0, 80);
+        return trimmed.Length == 0 ? "part" : trimmed;
+    }
+
+    /// <summary>
+    /// Given a user-selected <paramref name="basePath"/> (e.g. "C:\reports\duplicates.csv"),
+    /// returns a partitioned path like "C:\reports\duplicates_{label}.csv".
+    /// </summary>
+    public static string BuildPartitionPath(string basePath, string partitionLabel)
+    {
+        var dir = Path.GetDirectoryName(basePath);
+        var stem = Path.GetFileNameWithoutExtension(basePath);
+        var ext = Path.GetExtension(basePath);
+        var safe = SanitizeFileName(partitionLabel);
+        var file = $"{stem}_{safe}{ext}";
+        return string.IsNullOrEmpty(dir) ? file : Path.Combine(dir, file);
+    }
+
+    /// <summary>
+    /// Extracts the site-collection root URL from an arbitrary SharePoint object URL.
+    /// e.g. https://t.sharepoint.com/sites/hr/Shared%20Documents/foo.docx →
+    ///      https://t.sharepoint.com/sites/hr
+    /// Falls back to scheme+host for root site collections.
+    /// </summary>
+    public static string DeriveSiteCollectionUrl(string objectUrl)
+    {
+        if (string.IsNullOrWhiteSpace(objectUrl)) return string.Empty;
+        if (!Uri.TryCreate(objectUrl, UriKind.Absolute, out var uri))
+            return objectUrl.TrimEnd('/');
+
+        var baseUrl = $"{uri.Scheme}://{uri.Host}";
+        var segments = uri.AbsolutePath.Trim('/').Split('/', StringSplitOptions.RemoveEmptyEntries);
+
+        if (segments.Length >= 2 &&
+            (segments[0].Equals("sites", StringComparison.OrdinalIgnoreCase) ||
+             segments[0].Equals("teams", StringComparison.OrdinalIgnoreCase)))
+        {
+            return $"{baseUrl}/{segments[0]}/{segments[1]}";
+        }
+        return baseUrl;
+    }
+
+    /// <summary>
+    /// Derives a short, human-friendly site label from a SharePoint site URL.
+    /// Falls back to the raw URL (sanitized) when parsing fails.
+    /// </summary>
+    public static string DeriveSiteLabel(string siteUrl, string? siteTitle = null)
+    {
+        if (!string.IsNullOrWhiteSpace(siteTitle)) return siteTitle!;
+        if (string.IsNullOrWhiteSpace(siteUrl)) return "site";
+        try
+        {
+            var uri = new Uri(siteUrl);
+            var segments = uri.AbsolutePath.Trim('/').Split('/', StringSplitOptions.RemoveEmptyEntries);
+            if (segments.Length >= 2 &&
+                (segments[0].Equals("sites", StringComparison.OrdinalIgnoreCase) ||
+                 segments[0].Equals("teams", StringComparison.OrdinalIgnoreCase)))
+            {
+                return segments[1];
+            }
+            return uri.Host;
+        }
+        catch (Exception ex) when (ex is UriFormatException or ArgumentException)
+        {
+            Debug.WriteLine($"[ReportSplitHelper] DeriveSiteLabel: malformed URL '{siteUrl}' ({ex.GetType().Name}: {ex.Message}) — falling back to raw value.");
+            return siteUrl;
+        }
+    }
+
+    /// <summary>
+    /// Generic dispatcher for split-aware export: if
+    /// <paramref name="splitMode"/> is not BySite, writes a single file via
+    /// <paramref name="writer"/>; otherwise partitions via
+    /// <paramref name="partitioner"/> and writes one file per partition,
+    /// each at a filename derived from <paramref name="basePath"/> plus the
+    /// partition label.
+    /// </summary>
+    public static async Task WritePartitionedAsync<T>(
+        IReadOnlyList<T> items,
+        string basePath,
+        ReportSplitMode splitMode,
+        Func<IReadOnlyList<T>, IEnumerable<(string Label, IReadOnlyList<T> Partition)>> partitioner,
+        Func<IReadOnlyList<T>, string, CancellationToken, Task> writer,
+        CancellationToken ct)
+    {
+        if (splitMode != ReportSplitMode.BySite)
+        {
+            await writer(items, basePath, ct);
+            return;
+        }
+
+        foreach (var (label, partition) in partitioner(items))
+        {
+            ct.ThrowIfCancellationRequested();
+            var path = BuildPartitionPath(basePath, label);
+            await writer(partition, path, ct);
+        }
+    }
+
+    /// <summary>
+    /// Bundles per-partition HTML documents into one self-contained tabbed
+    /// HTML. Each partition HTML is embedded in an &lt;iframe srcdoc&gt; so
+    /// their inline styles and scripts remain isolated.
+    /// </summary>
+    public static string BuildTabbedHtml(
+        IReadOnlyList<(string Label, string Html)> parts,
+        string title)
+    {
+        var sb = new StringBuilder();
+        sb.AppendLine("<!DOCTYPE html>");
+        sb.AppendLine("<html lang=\"en\">");
+        sb.AppendLine("<head>");
+        sb.AppendLine("<meta charset=\"UTF-8\">");
+        sb.AppendLine("<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">");
+        sb.AppendLine($"<title>{WebUtility.HtmlEncode(title)}</title>");
+        sb.AppendLine("""
+            <style>
+              html, body { margin: 0; padding: 0; height: 100%; font-family: 'Segoe UI', Arial, sans-serif; background: #1a1a2e; }
+              .tabbar { display: flex; flex-wrap: wrap; gap: 4px; background: #1a1a2e; padding: 8px; position: sticky; top: 0; z-index: 10; }
+              .tab { padding: 6px 12px; background: #2d2d4e; color: #fff; cursor: pointer; border-radius: 4px;
+                     font-size: 13px; user-select: none; white-space: nowrap; }
+              .tab:hover { background: #3d3d6e; }
+              .tab.active { background: #0078d4; }
+              .frame-host { background: #f5f5f5; }
+              iframe { width: 100%; height: calc(100vh - 52px); border: 0; display: none; background: #f5f5f5; }
+              iframe.active { display: block; }
+            </style>
+            </head>
+            <body>
+            """);
+        sb.Append("<div class=\"tabbar\">");
+        for (int i = 0; i < parts.Count; i++)
+        {
+            var cls = i == 0 ? "tab active" : "tab";
+            sb.Append($"<div class=\"{cls}\" onclick=\"showTab({i})\">{WebUtility.HtmlEncode(parts[i].Label)}</div>");
+        }
+        sb.AppendLine("</div>");
+
+        for (int i = 0; i < parts.Count; i++)
+        {
+            var cls = i == 0 ? "active" : string.Empty;
+            var escaped = EscapeForSrcdoc(parts[i].Html);
+            sb.AppendLine($"<iframe class=\"{cls}\" srcdoc=\"{escaped}\"></iframe>");
+        }
+        sb.AppendLine("""
+            <script>
+              function showTab(i) {
+                var frames = document.querySelectorAll('iframe');
+                var tabs = document.querySelectorAll('.tab');
+                for (var j = 0; j < frames.length; j++) {
+                  frames[j].classList.toggle('active', i === j);
+                  tabs[j].classList.toggle('active', i === j);
+                }
+              }
+            </script>
+            </body></html>
+            """);
+        return sb.ToString();
+    }
+
+    /// <summary>
+    /// Escapes an HTML document so it can safely appear inside an
+    /// &lt;iframe srcdoc="..."&gt; attribute. Only ampersands and double
+    /// quotes must be encoded; angle brackets are kept literal because the
+    /// parser treats srcdoc as CDATA-like content.
+    /// </summary>
+    private static string EscapeForSrcdoc(string html)
+    {
+        if (string.IsNullOrEmpty(html)) return string.Empty;
+        return html
+            .Replace("&", "&amp;")
+            .Replace("\"", "&quot;");
+    }
+}
@@ -0,0 +1,16 @@
+namespace SharepointToolbox.Services.Export;
+
+/// <summary>How a report export is partitioned.</summary>
+public enum ReportSplitMode
+{
+    Single,
+    BySite,
+    ByUser
+}
+
+/// <summary>When a report is split, how HTML output is laid out.</summary>
+public enum HtmlSplitLayout
+{
+    SeparateFiles,
+    SingleTabbed
+}
@@ -1,6 +1,7 @@
 using System.IO;
 using System.Text;
 using SharepointToolbox.Core.Models;
+using SharepointToolbox.Localization;

 namespace SharepointToolbox.Services.Export;

@@ -10,12 +11,17 @@ namespace SharepointToolbox.Services.Export;
 /// </summary>
 public class SearchCsvExportService
 {
+    /// <summary>
+    /// Builds the CSV payload. Column order mirrors
+    /// <see cref="SearchHtmlExportService.BuildHtml(IReadOnlyList{SearchResult}, ReportBranding?)"/>.
+    /// </summary>
    public string BuildCsv(IReadOnlyList<SearchResult> results)
    {
+        var T = TranslationSource.Instance;
        var sb = new StringBuilder();

        // Header
-        sb.AppendLine("File Name,Extension,Path,Created,Created By,Modified,Modified By,Size (bytes)");
+        sb.AppendLine($"{T["report.col.file_name"]},{T["report.col.extension"]},{T["report.col.path"]},{T["report.col.created"]},{T["report.col.created_by"]},{T["report.col.modified"]},{T["report.col.modified_by"]},{T["report.col.size_bytes"]}");

        foreach (var r in results)
        {
@@ -33,19 +39,14 @@ public class SearchCsvExportService
        return sb.ToString();
    }

+    /// <summary>Writes the CSV to <paramref name="filePath"/> with UTF-8 BOM.</summary>
    public async Task WriteAsync(IReadOnlyList<SearchResult> results, string filePath, CancellationToken ct)
    {
        var csv = BuildCsv(results);
-        await System.IO.File.WriteAllTextAsync(filePath, csv, new UTF8Encoding(encoderShouldEmitUTF8Identifier: true), ct);
+        await ExportFileWriter.WriteCsvAsync(filePath, csv, ct);
    }

-    private static string Csv(string value)
-    {
-        if (string.IsNullOrEmpty(value)) return string.Empty;
-        if (value.Contains(',') || value.Contains('"') || value.Contains('\n'))
-            return $"\"{value.Replace("\"", "\"\"")}\"";
-        return value;
-    }
+    private static string Csv(string value) => CsvSanitizer.EscapeMinimal(value);

    private static string IfEmpty(string? value, string fallback = "")
        => string.IsNullOrEmpty(value) ? fallback : value!;
@@ -1,6 +1,7 @@
 using System.IO;
 using System.Text;
 using SharepointToolbox.Core.Models;
+using SharepointToolbox.Localization;

 namespace SharepointToolbox.Services.Export;

@@ -11,17 +12,23 @@ namespace SharepointToolbox.Services.Export;
 /// </summary>
 public class SearchHtmlExportService
 {
+    /// <summary>
+    /// Builds a self-contained HTML table with inline sort/filter scripts.
+    /// Each <see cref="SearchResult"/> becomes one row; the document has no
+    /// external dependencies.
+    /// </summary>
    public string BuildHtml(IReadOnlyList<SearchResult> results, ReportBranding? branding = null)
    {
+        var T = TranslationSource.Instance;
        var sb = new StringBuilder();

+        sb.AppendLine("<!DOCTYPE html>");
+        sb.AppendLine("<html lang=\"en\">");
+        sb.AppendLine("<head>");
+        sb.AppendLine("<meta charset=\"UTF-8\">");
+        sb.AppendLine("<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">");
+        sb.AppendLine($"<title>{T["report.title.search"]}</title>");
        sb.AppendLine("""
-            <!DOCTYPE html>
-            <html lang="en">
-            <head>
-            <meta charset="UTF-8">
-            <meta name="viewport" content="width=device-width, initial-scale=1.0">
-            <title>SharePoint File Search Results</title>
            <style>
              body { font-family: 'Segoe UI', Arial, sans-serif; font-size: 13px; margin: 20px; background: #f5f5f5; }
              h1 { color: #0078d4; }
@@ -45,27 +52,27 @@ public class SearchHtmlExportService
            <body>
            """);
        sb.Append(BrandingHtmlHelper.BuildBrandingHeader(branding));
-        sb.AppendLine("""
-            <h1>File Search Results</h1>
+        sb.AppendLine($"""
+            <h1>{T["report.title.search_short"]}</h1>
            <div class="toolbar">
-              <label for="filterInput">Filter:</label>
-              <input id="filterInput" type="text" placeholder="Filter rows…" oninput="filterTable()" />
+              <label for="filterInput">{T["report.filter.label"]}</label>
+              <input id="filterInput" type="text" placeholder="{T["report.filter.placeholder_rows"]}" oninput="filterTable()" />
              <span id="resultCount"></span>
            </div>
            """);

-        sb.AppendLine("""
+        sb.AppendLine($"""
            <table id="resultsTable">
              <thead>
                <tr>
-                  <th onclick="sortTable(0)">File Name</th>
-                  <th onclick="sortTable(1)">Extension</th>
-                  <th onclick="sortTable(2)">Path</th>
-                  <th onclick="sortTable(3)">Created</th>
-                  <th onclick="sortTable(4)">Created By</th>
-                  <th onclick="sortTable(5)">Modified</th>
-                  <th onclick="sortTable(6)">Modified By</th>
-                  <th class="num" onclick="sortTable(7)">Size</th>
+                  <th onclick="sortTable(0)">{T["report.col.file_name"]}</th>
+                  <th onclick="sortTable(1)">{T["report.col.extension"]}</th>
+                  <th onclick="sortTable(2)">{T["report.col.path"]}</th>
+                  <th onclick="sortTable(3)">{T["report.col.created"]}</th>
+                  <th onclick="sortTable(4)">{T["report.col.created_by"]}</th>
+                  <th onclick="sortTable(5)">{T["report.col.modified"]}</th>
+                  <th onclick="sortTable(6)">{T["report.col.modified_by"]}</th>
+                  <th class="num" onclick="sortTable(7)">{T["report.col.size"]}</th>
                </tr>
              </thead>
              <tbody>
@@ -93,7 +100,7 @@ public class SearchHtmlExportService
        sb.AppendLine("  </tbody>\n</table>");

        int count = results.Count;
-        sb.AppendLine($"<p class=\"generated\">Generated: {DateTime.Now:yyyy-MM-dd HH:mm} — {count:N0} result(s)</p>");
+        sb.AppendLine($"<p class=\"generated\">{T["report.text.generated_colon"]} {DateTime.Now:yyyy-MM-dd HH:mm} — {count:N0} {T["report.text.results_parens"]}</p>");

        sb.AppendLine($$"""
            <script>
@@ -126,10 +133,10 @@ public class SearchHtmlExportService
                rows[i].className = match ? '' : 'hidden';
                if (match) visible++;
              }
-              document.getElementById('resultCount').innerText = q ? (visible + ' of {{count:N0}} shown') : '';
+              document.getElementById('resultCount').innerText = q ? (visible + ' {{T["report.text.of"]}} {{count:N0}} {{T["report.text.shown"]}}') : '';
            }
            window.onload = function() {
-              document.getElementById('resultCount').innerText = '{{count:N0}} result(s)';
+              document.getElementById('resultCount').innerText = '{{count:N0}} {{T["report.text.results_parens"]}}';
            };
            </script>
            </body></html>
@@ -138,6 +145,7 @@ public class SearchHtmlExportService
        return sb.ToString();
    }

+    /// <summary>Writes the HTML report to <paramref name="filePath"/>.</summary>
    public async Task WriteAsync(IReadOnlyList<SearchResult> results, string filePath, CancellationToken ct, ReportBranding? branding = null)
    {
        var html = BuildHtml(results, branding);
@@ -1,4 +1,5 @@
 using SharepointToolbox.Core.Models;
+using SharepointToolbox.Localization;
 using System.IO;
 using System.Text;

@@ -10,12 +11,18 @@ namespace SharepointToolbox.Services.Export;
 /// </summary>
 public class StorageCsvExportService
 {
+    /// <summary>
+    /// Builds a single-section CSV: header row plus one row per
+    /// <see cref="StorageNode"/> with library, site, file count, total size
+    /// (MB), version size (MB), and last-modified date.
+    /// </summary>
    public string BuildCsv(IReadOnlyList<StorageNode> nodes)
    {
+        var T = TranslationSource.Instance;
        var sb = new StringBuilder();

        // Header
-        sb.AppendLine("Library,Site,Files,Total Size (MB),Version Size (MB),Last Modified");
+        sb.AppendLine($"{T["report.col.library"]},{T["report.col.site"]},{T["report.stat.files"]},{T["report.col.total_size_mb"]},{T["report.col.version_size_mb"]},{T["report.col.last_modified"]}");

        foreach (var node in nodes)
        {
@@ -33,10 +40,11 @@ public class StorageCsvExportService
        return sb.ToString();
    }

+    /// <summary>Writes the library-level CSV to <paramref name="filePath"/> with UTF-8 BOM.</summary>
    public async Task WriteAsync(IReadOnlyList<StorageNode> nodes, string filePath, CancellationToken ct)
    {
        var csv = BuildCsv(nodes);
-        await File.WriteAllTextAsync(filePath, csv, new UTF8Encoding(encoderShouldEmitUTF8Identifier: true), ct);
+        await ExportFileWriter.WriteCsvAsync(filePath, csv, ct);
    }

    /// <summary>
@@ -44,10 +52,11 @@ public class StorageCsvExportService
    /// </summary>
    public string BuildCsv(IReadOnlyList<StorageNode> nodes, IReadOnlyList<FileTypeMetric> fileTypeMetrics)
    {
+        var T = TranslationSource.Instance;
        var sb = new StringBuilder();

        // Library details
-        sb.AppendLine("Library,Site,Files,Total Size (MB),Version Size (MB),Last Modified");
+        sb.AppendLine($"{T["report.col.library"]},{T["report.col.site"]},{T["report.stat.files"]},{T["report.col.total_size_mb"]},{T["report.col.version_size_mb"]},{T["report.col.last_modified"]}");
        foreach (var node in nodes)
        {
            sb.AppendLine(string.Join(",",
@@ -65,10 +74,10 @@ public class StorageCsvExportService
        if (fileTypeMetrics.Count > 0)
        {
            sb.AppendLine();
-            sb.AppendLine("File Type,Size (MB),File Count");
+            sb.AppendLine($"{T["report.col.file_type"]},{T["report.col.size_mb"]},{T["report.col.file_count"]}");
            foreach (var m in fileTypeMetrics)
            {
-                string label = string.IsNullOrEmpty(m.Extension) ? "(no extension)" : m.Extension;
+                string label = string.IsNullOrEmpty(m.Extension) ? T["report.text.no_extension"] : m.Extension;
                sb.AppendLine(string.Join(",", Csv(label), FormatMb(m.TotalSizeBytes), m.FileCount.ToString()));
            }
        }
@@ -76,10 +85,55 @@ public class StorageCsvExportService
        return sb.ToString();
    }

+    /// <summary>Writes the two-section CSV (libraries + file-type breakdown) with UTF-8 BOM.</summary>
    public async Task WriteAsync(IReadOnlyList<StorageNode> nodes, IReadOnlyList<FileTypeMetric> fileTypeMetrics, string filePath, CancellationToken ct)
    {
        var csv = BuildCsv(nodes, fileTypeMetrics);
-        await File.WriteAllTextAsync(filePath, csv, new UTF8Encoding(encoderShouldEmitUTF8Identifier: true), ct);
+        await ExportFileWriter.WriteCsvAsync(filePath, csv, ct);
+    }
+
+    /// <summary>
+    /// Writes storage metrics with optional per-site partitioning.
+    /// Single → one file. BySite → one file per SiteTitle. File-type metrics
+    /// are replicated across all partitions because the tenant-level scan
+    /// does not retain per-site breakdowns.
+    /// </summary>
+    public Task WriteAsync(
+        IReadOnlyList<StorageNode> nodes,
+        IReadOnlyList<FileTypeMetric> fileTypeMetrics,
+        string basePath,
+        ReportSplitMode splitMode,
+        CancellationToken ct)
+        => ReportSplitHelper.WritePartitionedAsync(
+            nodes, basePath, splitMode,
+            PartitionBySite,
+            (part, path, c) => WriteAsync(part, fileTypeMetrics, path, c),
+            ct);
+
+    /// <summary>
+    /// Splits the flat StorageNode list into per-site slices while preserving
+    /// the DFS hierarchy (each root library followed by its indented descendants).
+    /// Siblings sharing a SiteTitle roll up into the same partition.
+    /// </summary>
+    internal static IEnumerable<(string Label, IReadOnlyList<StorageNode> Partition)> PartitionBySite(
+        IReadOnlyList<StorageNode> nodes)
+    {
+        var buckets = new Dictionary<string, List<StorageNode>>(StringComparer.OrdinalIgnoreCase);
+        string currentSite = string.Empty;
+        foreach (var node in nodes)
+        {
+            if (node.IndentLevel == 0)
+                currentSite = string.IsNullOrWhiteSpace(node.SiteTitle)
+                    ? ReportSplitHelper.DeriveSiteLabel(node.Url)
+                    : node.SiteTitle;
+            if (!buckets.TryGetValue(currentSite, out var list))
+            {
+                list = new List<StorageNode>();
+                buckets[currentSite] = list;
+            }
+            list.Add(node);
+        }
+        return buckets.Select(kv => (kv.Key, (IReadOnlyList<StorageNode>)kv.Value));
    }

    // ── Helpers ───────────────────────────────────────────────────────────────
@@ -87,12 +141,6 @@ public class StorageCsvExportService
    private static string FormatMb(long bytes)
        => (bytes / (1024.0 * 1024.0)).ToString("F2");

-    /// <summary>RFC 4180 CSV field quoting.</summary>
-    private static string Csv(string value)
-    {
-        if (string.IsNullOrEmpty(value)) return string.Empty;
-        if (value.Contains(',') || value.Contains('"') || value.Contains('\n'))
-            return $"\"{value.Replace("\"", "\"\"")}\"";
-        return value;
-    }
+    /// <summary>RFC 4180 CSV field quoting with formula-injection guard.</summary>
+    private static string Csv(string value) => CsvSanitizer.EscapeMinimal(value);
 }
@@ -1,4 +1,5 @@
 using SharepointToolbox.Core.Models;
+using SharepointToolbox.Localization;
 using System.IO;
 using System.Text;

@@ -13,18 +14,25 @@ public class StorageHtmlExportService
 {
    private int _togIdx;

+    /// <summary>
+    /// Builds a self-contained HTML report with one collapsible row per
+    /// library and indented child folders. Library-only variant — use the
+    /// overload that accepts <see cref="FileTypeMetric"/>s when a file-type
+    /// breakdown section is desired.
+    /// </summary>
    public string BuildHtml(IReadOnlyList<StorageNode> nodes, ReportBranding? branding = null)
    {
+        var T = TranslationSource.Instance;
        _togIdx = 0;
        var sb = new StringBuilder();

+        sb.AppendLine("<!DOCTYPE html>");
+        sb.AppendLine("<html lang=\"en\">");
+        sb.AppendLine("<head>");
+        sb.AppendLine("<meta charset=\"UTF-8\">");
+        sb.AppendLine("<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">");
+        sb.AppendLine($"<title>{T["report.title.storage"]}</title>");
        sb.AppendLine("""
-            <!DOCTYPE html>
-            <html lang="en">
-            <head>
-            <meta charset="UTF-8">
-            <meta name="viewport" content="width=device-width, initial-scale=1.0">
-            <title>SharePoint Storage Metrics</title>
            <style>
              body { font-family: 'Segoe UI', Arial, sans-serif; font-size: 13px; margin: 20px; background: #f5f5f5; }
              h1 { color: #0078d4; }
@@ -50,9 +58,7 @@ public class StorageHtmlExportService
            <body>
            """);
        sb.Append(BrandingHtmlHelper.BuildBrandingHeader(branding));
-        sb.AppendLine("""
-            <h1>SharePoint Storage Metrics</h1>
-            """);
+        sb.AppendLine($"<h1>{T["report.title.storage"]}</h1>");

        // Summary cards
        var rootNodes0 = nodes.Where(n => n.IndentLevel == 0).ToList();
@@ -62,22 +68,22 @@ public class StorageHtmlExportService

        sb.AppendLine($"""
            <div style="display:flex;gap:16px;margin:16px 0;flex-wrap:wrap">
-              <div style="background:#fff;border-radius:8px;padding:14px 20px;min-width:160px;box-shadow:0 1px 4px rgba(0,0,0,.1)"><div style="font-size:1.8rem;font-weight:700;color:#0078d4">{FormatSize(siteTotal0)}</div><div style="font-size:.8rem;color:#666">Total Size</div></div>
-              <div style="background:#fff;border-radius:8px;padding:14px 20px;min-width:160px;box-shadow:0 1px 4px rgba(0,0,0,.1)"><div style="font-size:1.8rem;font-weight:700;color:#0078d4">{FormatSize(versionTotal0)}</div><div style="font-size:.8rem;color:#666">Version Size</div></div>
-              <div style="background:#fff;border-radius:8px;padding:14px 20px;min-width:160px;box-shadow:0 1px 4px rgba(0,0,0,.1)"><div style="font-size:1.8rem;font-weight:700;color:#0078d4">{fileTotal0:N0}</div><div style="font-size:.8rem;color:#666">Files</div></div>
+              <div style="background:#fff;border-radius:8px;padding:14px 20px;min-width:160px;box-shadow:0 1px 4px rgba(0,0,0,.1)"><div style="font-size:1.8rem;font-weight:700;color:#0078d4">{FormatSize(siteTotal0)}</div><div style="font-size:.8rem;color:#666">{T["report.stat.total_size"]}</div></div>
+              <div style="background:#fff;border-radius:8px;padding:14px 20px;min-width:160px;box-shadow:0 1px 4px rgba(0,0,0,.1)"><div style="font-size:1.8rem;font-weight:700;color:#0078d4">{FormatSize(versionTotal0)}</div><div style="font-size:.8rem;color:#666">{T["report.stat.version_size"]}</div></div>
+              <div style="background:#fff;border-radius:8px;padding:14px 20px;min-width:160px;box-shadow:0 1px 4px rgba(0,0,0,.1)"><div style="font-size:1.8rem;font-weight:700;color:#0078d4">{fileTotal0:N0}</div><div style="font-size:.8rem;color:#666">{T["report.stat.files"]}</div></div>
            </div>
            """);

-        sb.AppendLine("""
+        sb.AppendLine($"""
            <table>
              <thead>
                <tr>
-                  <th>Library / Folder</th>
-                  <th>Site</th>
-                  <th class="num">Files</th>
-                  <th class="num">Total Size</th>
-                  <th class="num">Version Size</th>
-                  <th>Last Modified</th>
+                  <th>{T["report.col.library_folder"]}</th>
+                  <th>{T["report.col.site"]}</th>
+                  <th class="num">{T["report.stat.files"]}</th>
+                  <th class="num">{T["report.stat.total_size"]}</th>
+                  <th class="num">{T["report.stat.version_size"]}</th>
+                  <th>{T["report.col.last_modified"]}</th>
                </tr>
              </thead>
              <tbody>
@@ -93,7 +99,7 @@ public class StorageHtmlExportService
            </table>
            """);

-        sb.AppendLine($"<p class=\"generated\">Generated: {DateTime.Now:yyyy-MM-dd HH:mm}</p>");
+        sb.AppendLine($"<p class=\"generated\">{T["report.text.generated_colon"]} {DateTime.Now:yyyy-MM-dd HH:mm}</p>");
        sb.AppendLine("</body></html>");

        return sb.ToString();
@@ -104,16 +110,17 @@ public class StorageHtmlExportService
    /// </summary>
    public string BuildHtml(IReadOnlyList<StorageNode> nodes, IReadOnlyList<FileTypeMetric> fileTypeMetrics, ReportBranding? branding = null)
    {
+        var T = TranslationSource.Instance;
        _togIdx = 0;
        var sb = new StringBuilder();

+        sb.AppendLine("<!DOCTYPE html>");
+        sb.AppendLine("<html lang=\"en\">");
+        sb.AppendLine("<head>");
+        sb.AppendLine("<meta charset=\"UTF-8\">");
+        sb.AppendLine("<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">");
+        sb.AppendLine($"<title>{T["report.title.storage"]}</title>");
        sb.AppendLine("""
-            <!DOCTYPE html>
-            <html lang="en">
-            <head>
-            <meta charset="UTF-8">
-            <meta name="viewport" content="width=device-width, initial-scale=1.0">
-            <title>SharePoint Storage Metrics</title>
            <style>
              body { font-family: 'Segoe UI', Arial, sans-serif; font-size: 13px; margin: 20px; background: #f5f5f5; }
              h1 { color: #0078d4; }
@@ -150,9 +157,7 @@ public class StorageHtmlExportService
            <body>
            """);
        sb.Append(BrandingHtmlHelper.BuildBrandingHeader(branding));
-        sb.AppendLine("""
-            <h1>SharePoint Storage Metrics</h1>
-            """);
+        sb.AppendLine($"<h1>{T["report.title.storage"]}</h1>");

        // ── Summary cards ──
        var rootNodes = nodes.Where(n => n.IndentLevel == 0).ToList();
@@ -161,10 +166,10 @@ public class StorageHtmlExportService
        long fileTotal = rootNodes.Sum(n => n.TotalFileCount);

        sb.AppendLine("<div class=\"stats\">");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{FormatSize(siteTotal)}</div><div class=\"label\">Total Size</div></div>");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{FormatSize(versionTotal)}</div><div class=\"label\">Version Size</div></div>");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{fileTotal:N0}</div><div class=\"label\">Files</div></div>");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{rootNodes.Count}</div><div class=\"label\">Libraries</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{FormatSize(siteTotal)}</div><div class=\"label\">{T["report.stat.total_size"]}</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{FormatSize(versionTotal)}</div><div class=\"label\">{T["report.stat.version_size"]}</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{fileTotal:N0}</div><div class=\"label\">{T["report.stat.files"]}</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{rootNodes.Count}</div><div class=\"label\">{T["report.stat.libraries"]}</div></div>");
        sb.AppendLine("</div>");

        // ── File type chart section ──
@@ -175,7 +180,7 @@ public class StorageHtmlExportService
            var totalFiles = fileTypeMetrics.Sum(m => m.FileCount);

            sb.AppendLine("<div class=\"chart-section\">");
-            sb.AppendLine($"<h2>Storage by File Type ({totalFiles:N0} files, {FormatSize(totalSize)})</h2>");
+            sb.AppendLine($"<h2>{T["report.section.storage_by_file_type"]} ({totalFiles:N0} {T["report.text.files_unit"]}, {FormatSize(totalSize)})</h2>");

            var colors = new[] { "#0078d4", "#2b88d8", "#106ebe", "#005a9e", "#004578",
                                 "#00bcf2", "#009e49", "#8cbd18", "#ffb900", "#d83b01" };
@@ -185,13 +190,13 @@ public class StorageHtmlExportService
            {
                double pct = maxSize > 0 ? m.TotalSizeBytes * 100.0 / maxSize : 0;
                string color = colors[idx % colors.Length];
-                string label = string.IsNullOrEmpty(m.Extension) ? "(no ext)" : m.Extension;
+                string label = string.IsNullOrEmpty(m.Extension) ? T["report.text.no_ext"] : m.Extension;

                sb.AppendLine($"""
                    <div class="bar-row">
                      <span class="bar-label">{HtmlEncode(label)}</span>
                      <div class="bar-track"><div class="bar-fill" style="width:{pct:F1}%;background:{color}"></div></div>
-                      <span class="bar-value">{FormatSize(m.TotalSizeBytes)} &middot; {m.FileCount:N0} files</span>
+                      <span class="bar-value">{FormatSize(m.TotalSizeBytes)} &middot; {m.FileCount:N0} {T["report.text.files_unit"]}</span>
                    </div>
                    """);
                idx++;
@@ -201,17 +206,17 @@ public class StorageHtmlExportService
        }

        // ── Storage table ──
-        sb.AppendLine("<h2>Library Details</h2>");
-        sb.AppendLine("""
+        sb.AppendLine($"<h2>{T["report.section.library_details"]}</h2>");
+        sb.AppendLine($"""
            <table>
              <thead>
                <tr>
-                  <th>Library / Folder</th>
-                  <th>Site</th>
-                  <th class="num">Files</th>
-                  <th class="num">Total Size</th>
-                  <th class="num">Version Size</th>
-                  <th>Last Modified</th>
+                  <th>{T["report.col.library_folder"]}</th>
+                  <th>{T["report.col.site"]}</th>
+                  <th class="num">{T["report.stat.files"]}</th>
+                  <th class="num">{T["report.stat.total_size"]}</th>
+                  <th class="num">{T["report.stat.version_size"]}</th>
+                  <th>{T["report.col.last_modified"]}</th>
                </tr>
              </thead>
              <tbody>
@@ -227,24 +232,68 @@ public class StorageHtmlExportService
            </table>
            """);

-        sb.AppendLine($"<p class=\"generated\">Generated: {DateTime.Now:yyyy-MM-dd HH:mm}</p>");
+        sb.AppendLine($"<p class=\"generated\">{T["report.text.generated_colon"]} {DateTime.Now:yyyy-MM-dd HH:mm}</p>");
        sb.AppendLine("</body></html>");

        return sb.ToString();
    }

+    /// <summary>Writes the library-only HTML report to <paramref name="filePath"/>.</summary>
    public async Task WriteAsync(IReadOnlyList<StorageNode> nodes, string filePath, CancellationToken ct, ReportBranding? branding = null)
    {
        var html = BuildHtml(nodes, branding);
        await File.WriteAllTextAsync(filePath, html, Encoding.UTF8, ct);
    }

+    /// <summary>Writes the HTML report including the file-type breakdown chart.</summary>
    public async Task WriteAsync(IReadOnlyList<StorageNode> nodes, IReadOnlyList<FileTypeMetric> fileTypeMetrics, string filePath, CancellationToken ct, ReportBranding? branding = null)
    {
        var html = BuildHtml(nodes, fileTypeMetrics, branding);
        await File.WriteAllTextAsync(filePath, html, Encoding.UTF8, ct);
    }

+    /// <summary>
+    /// Split-aware HTML export for storage metrics.
+    /// Single → one file. BySite + SeparateFiles → one file per site.
+    /// BySite + SingleTabbed → one HTML with per-site iframe tabs. File-type
+    /// metrics are replicated across partitions because they are not
+    /// attributed per-site by the scanner.
+    /// </summary>
+    public async Task WriteAsync(
+        IReadOnlyList<StorageNode> nodes,
+        IReadOnlyList<FileTypeMetric> fileTypeMetrics,
+        string basePath,
+        ReportSplitMode splitMode,
+        HtmlSplitLayout layout,
+        CancellationToken ct,
+        ReportBranding? branding = null)
+    {
+        if (splitMode != ReportSplitMode.BySite)
+        {
+            await WriteAsync(nodes, fileTypeMetrics, basePath, ct, branding);
+            return;
+        }
+
+        var partitions = StorageCsvExportService.PartitionBySite(nodes).ToList();
+        if (layout == HtmlSplitLayout.SingleTabbed)
+        {
+            var parts = partitions
+                .Select(p => (p.Label, Html: BuildHtml(p.Partition, fileTypeMetrics, branding)))
+                .ToList();
+            var title = TranslationSource.Instance["report.title.storage"];
+            var tabbed = ReportSplitHelper.BuildTabbedHtml(parts, title);
+            await File.WriteAllTextAsync(basePath, tabbed, Encoding.UTF8, ct);
+            return;
+        }
+
+        foreach (var (label, partNodes) in partitions)
+        {
+            ct.ThrowIfCancellationRequested();
+            var path = ReportSplitHelper.BuildPartitionPath(basePath, label);
+            await WriteAsync(partNodes, fileTypeMetrics, path, ct, branding);
+        }
+    }
+
    // ── Private rendering ────────────────────────────────────────────────────

    private void RenderNode(StringBuilder sb, StorageNode node)
@@ -2,6 +2,7 @@ using System.IO;
 using System.Text;
 using SharepointToolbox.Core.Helpers;
 using SharepointToolbox.Core.Models;
+using SharepointToolbox.Localization;

 namespace SharepointToolbox.Services.Export;

@@ -11,8 +12,11 @@ namespace SharepointToolbox.Services.Export;
 /// </summary>
 public class UserAccessCsvExportService
 {
-    private const string DataHeader =
-        "\"Site\",\"Object Type\",\"Object\",\"URL\",\"Permission Level\",\"Access Type\",\"Granted Through\"";
+    private static string BuildDataHeader()
+    {
+        var T = TranslationSource.Instance;
+        return $"\"{T["report.col.site"]}\",\"{T["report.col.object_type"]}\",\"{T["report.col.object"]}\",\"{T["report.col.url"]}\",\"{T["report.col.permission_level"]}\",\"{T["report.col.access_type"]}\",\"{T["report.col.granted_through"]}\"";
+    }

    /// <summary>
    /// Builds a CSV string for a single user's access entries.
@@ -20,22 +24,23 @@ public class UserAccessCsvExportService
    /// </summary>
    public string BuildCsv(string userDisplayName, string userLogin, IReadOnlyList<UserAccessEntry> entries)
    {
+        var T = TranslationSource.Instance;
        var sb = new StringBuilder();

        // Summary section
        var sitesCount = entries.Select(e => e.SiteUrl).Distinct().Count();
        var highPrivCount = entries.Count(e => e.IsHighPrivilege);

-        sb.AppendLine($"\"User Access Audit Report\"");
-        sb.AppendLine($"\"User\",\"{Csv(userDisplayName)} ({Csv(userLogin)})\"");
-        sb.AppendLine($"\"Total Accesses\",\"{entries.Count}\"");
-        sb.AppendLine($"\"Sites\",\"{sitesCount}\"");
-        sb.AppendLine($"\"High Privilege\",\"{highPrivCount}\"");
-        sb.AppendLine($"\"Generated\",\"{DateTime.Now:yyyy-MM-dd HH:mm:ss}\"");
+        sb.AppendLine($"\"{T["report.title.user_access"]}\"");
+        sb.AppendLine($"\"{T["report.col.user"]}\",\"{Csv(userDisplayName)} ({Csv(userLogin)})\"");
+        sb.AppendLine($"\"{T["report.stat.total_accesses"]}\",\"{entries.Count}\"");
+        sb.AppendLine($"\"{T["report.col.sites"]}\",\"{sitesCount}\"");
+        sb.AppendLine($"\"{T["report.stat.high_privilege"]}\",\"{highPrivCount}\"");
+        sb.AppendLine($"\"{T["report.text.generated"]}\",\"{DateTime.Now:yyyy-MM-dd HH:mm:ss}\"");
        sb.AppendLine(); // Blank line separating summary from data

        // Data rows
-        sb.AppendLine(DataHeader);
+        sb.AppendLine(BuildDataHeader());
        foreach (var entry in entries)
        {
            sb.AppendLine(string.Join(",", new[]
@@ -82,8 +87,69 @@ public class UserAccessCsvExportService
            var filePath = Path.Combine(directoryPath, fileName);

            var csv = BuildCsv(displayName, userLogin, entries);
-            await File.WriteAllTextAsync(filePath, csv,
-                new UTF8Encoding(encoderShouldEmitUTF8Identifier: true), ct);
+            await ExportFileWriter.WriteCsvAsync(filePath, csv, ct);
+        }
+    }
+
+    /// <summary>
+    /// Writes all entries split per site. File naming: "{base}_{siteLabel}.csv".
+    /// </summary>
+    public async Task WriteBySiteAsync(
+        IReadOnlyList<UserAccessEntry> allEntries,
+        string basePath,
+        CancellationToken ct,
+        bool mergePermissions = false)
+    {
+        foreach (var group in allEntries.GroupBy(e => (e.SiteUrl, e.SiteTitle)))
+        {
+            ct.ThrowIfCancellationRequested();
+            var label = ReportSplitHelper.DeriveSiteLabel(group.Key.SiteUrl, group.Key.SiteTitle);
+            var path = ReportSplitHelper.BuildPartitionPath(basePath, label);
+            await WriteSingleFileAsync(group.ToList(), path, ct, mergePermissions);
+        }
+    }
+
+    /// <summary>
+    /// Split-aware export dispatcher.
+    /// Single → one file at <paramref name="basePath"/>.
+    /// BySite → one file per site. ByUser → one file per user.
+    /// </summary>
+    public async Task WriteAsync(
+        IReadOnlyList<UserAccessEntry> allEntries,
+        string basePath,
+        ReportSplitMode splitMode,
+        CancellationToken ct,
+        bool mergePermissions = false)
+    {
+        switch (splitMode)
+        {
+            case ReportSplitMode.Single:
+                await WriteSingleFileAsync(allEntries, basePath, ct, mergePermissions);
+                break;
+            case ReportSplitMode.BySite:
+                await WriteBySiteAsync(allEntries, basePath, ct, mergePermissions);
+                break;
+            case ReportSplitMode.ByUser:
+                await WriteByUserAsync(allEntries, basePath, ct, mergePermissions);
+                break;
+        }
+    }
+
+    /// <summary>
+    /// Writes one CSV per user using <paramref name="basePath"/> as a filename template.
+    /// </summary>
+    public async Task WriteByUserAsync(
+        IReadOnlyList<UserAccessEntry> allEntries,
+        string basePath,
+        CancellationToken ct,
+        bool mergePermissions = false)
+    {
+        foreach (var group in allEntries.GroupBy(e => e.UserLogin))
+        {
+            ct.ThrowIfCancellationRequested();
+            var label = ReportSplitHelper.SanitizeFileName(group.Key);
+            var path = ReportSplitHelper.BuildPartitionPath(basePath, label);
+            await WriteSingleFileAsync(group.ToList(), path, ct, mergePermissions);
        }
    }

@@ -99,20 +165,21 @@ public class UserAccessCsvExportService
        CancellationToken ct,
        bool mergePermissions = false)
    {
+        var T = TranslationSource.Instance;
        if (mergePermissions)
        {
            var consolidated = PermissionConsolidator.Consolidate(entries);
            var sb = new StringBuilder();

            // Summary section
-            sb.AppendLine("\"User Access Audit Report (Consolidated)\"");
-            sb.AppendLine($"\"Users Audited\",\"{consolidated.Select(e => e.UserLogin).Distinct().Count()}\"");
-            sb.AppendLine($"\"Total Entries\",\"{consolidated.Count}\"");
-            sb.AppendLine($"\"Generated\",\"{DateTime.Now:yyyy-MM-dd HH:mm:ss}\"");
+            sb.AppendLine($"\"{T["report.title.user_access_consolidated"]}\"");
+            sb.AppendLine($"\"{T["report.stat.users_audited"]}\",\"{consolidated.Select(e => e.UserLogin).Distinct().Count()}\"");
+            sb.AppendLine($"\"{T["report.stat.total_entries"]}\",\"{consolidated.Count}\"");
+            sb.AppendLine($"\"{T["report.text.generated"]}\",\"{DateTime.Now:yyyy-MM-dd HH:mm:ss}\"");
            sb.AppendLine();

            // Header
-            sb.AppendLine("\"User\",\"User Login\",\"Permission Level\",\"Access Type\",\"Granted Through\",\"Locations\",\"Location Count\"");
+            sb.AppendLine($"\"{T["report.col.user"]}\",\"User Login\",\"{T["report.col.permission_level"]}\",\"{T["report.col.access_type"]}\",\"{T["report.col.granted_through"]}\",\"Locations\",\"Location Count\"");

            // Data rows
            foreach (var entry in consolidated)
@@ -136,14 +203,14 @@ public class UserAccessCsvExportService

        {
        var sb = new StringBuilder();
-        var fullHeader = "\"User\",\"User Login\"," + DataHeader;
+        var fullHeader = $"\"{T["report.col.user"]}\",\"User Login\"," + BuildDataHeader();

        // Summary
        var users = entries.Select(e => e.UserLogin).Distinct().ToList();
-        sb.AppendLine($"\"User Access Audit Report\"");
-        sb.AppendLine($"\"Users Audited\",\"{users.Count}\"");
-        sb.AppendLine($"\"Total Accesses\",\"{entries.Count}\"");
-        sb.AppendLine($"\"Generated\",\"{DateTime.Now:yyyy-MM-dd HH:mm:ss}\"");
+        sb.AppendLine($"\"{T["report.title.user_access"]}\"");
+        sb.AppendLine($"\"{T["report.stat.users_audited"]}\",\"{users.Count}\"");
+        sb.AppendLine($"\"{T["report.stat.total_accesses"]}\",\"{entries.Count}\"");
+        sb.AppendLine($"\"{T["report.text.generated"]}\",\"{DateTime.Now:yyyy-MM-dd HH:mm:ss}\"");
        sb.AppendLine();

        sb.AppendLine(fullHeader);
@@ -163,17 +230,12 @@ public class UserAccessCsvExportService
            }));
        }

-        await File.WriteAllTextAsync(filePath, sb.ToString(),
-            new UTF8Encoding(encoderShouldEmitUTF8Identifier: true), ct);
+        await ExportFileWriter.WriteCsvAsync(filePath, sb.ToString(), ct);
        }
    }

-    /// <summary>RFC 4180 CSV field escaping: wrap in double quotes, double internal quotes.</summary>
-    private static string Csv(string value)
-    {
-        if (string.IsNullOrEmpty(value)) return "\"\"";
-        return $"\"{value.Replace("\"", "\"\"")}\"";
-    }
+    /// <summary>RFC 4180 CSV field escaping with formula-injection guard.</summary>
+    private static string Csv(string value) => CsvSanitizer.Escape(value);

    private static string SanitizeFileName(string name)
    {
@@ -2,6 +2,7 @@ using System.IO;
 using System.Text;
 using SharepointToolbox.Core.Helpers;
 using SharepointToolbox.Core.Models;
+using SharepointToolbox.Localization;

 namespace SharepointToolbox.Services.Export;

@@ -18,6 +19,70 @@ public class UserAccessHtmlExportService
    /// When <paramref name="mergePermissions"/> is true, renders a consolidated by-user
    /// report with an expandable Sites column instead of the dual by-user/by-site view.
    /// </summary>
+    /// <summary>
+    /// Split-aware HTML export. Single → one file.
+    /// BySite/ByUser + SeparateFiles → one file per site/user.
+    /// BySite/ByUser + SingleTabbed → one file with per-partition iframe tabs.
+    /// </summary>
+    public async Task WriteAsync(
+        IReadOnlyList<UserAccessEntry> entries,
+        string basePath,
+        ReportSplitMode splitMode,
+        HtmlSplitLayout layout,
+        CancellationToken ct,
+        bool mergePermissions = false,
+        ReportBranding? branding = null)
+    {
+        if (splitMode == ReportSplitMode.Single)
+        {
+            await WriteAsync(entries, basePath, ct, mergePermissions, branding);
+            return;
+        }
+
+        IEnumerable<(string Label, IReadOnlyList<UserAccessEntry> Entries)> partitions;
+        if (splitMode == ReportSplitMode.BySite)
+        {
+            partitions = entries
+                .GroupBy(e => (e.SiteUrl, e.SiteTitle))
+                .Select(g => (
+                    Label: ReportSplitHelper.DeriveSiteLabel(g.Key.SiteUrl, g.Key.SiteTitle),
+                    Entries: (IReadOnlyList<UserAccessEntry>)g.ToList()));
+        }
+        else // ByUser
+        {
+            partitions = entries
+                .GroupBy(e => e.UserLogin)
+                .Select(g => (
+                    Label: ReportSplitHelper.SanitizeFileName(g.Key),
+                    Entries: (IReadOnlyList<UserAccessEntry>)g.ToList()));
+        }
+
+        var partList = partitions.ToList();
+        if (layout == HtmlSplitLayout.SingleTabbed)
+        {
+            var parts = partList
+                .Select(p => (p.Label, Html: BuildHtml(p.Entries, mergePermissions, branding)))
+                .ToList();
+            var title = TranslationSource.Instance["report.title.user_access"];
+            var tabbed = ReportSplitHelper.BuildTabbedHtml(parts, title);
+            await ExportFileWriter.WriteHtmlAsync(basePath, tabbed, ct);
+            return;
+        }
+
+        foreach (var (label, partEntries) in partList)
+        {
+            ct.ThrowIfCancellationRequested();
+            var path = ReportSplitHelper.BuildPartitionPath(basePath, label);
+            await WriteAsync(partEntries, path, ct, mergePermissions, branding);
+        }
+    }
+
+    /// <summary>
+    /// Builds the user-access HTML report. Default layout is a per-entry
+    /// grouped-by-user table; when <paramref name="mergePermissions"/> is true
+    /// entries are consolidated via <see cref="PermissionConsolidator"/> into
+    /// a single-row-per-user format with a Locations column.
+    /// </summary>
    public string BuildHtml(IReadOnlyList<UserAccessEntry> entries, bool mergePermissions = false, ReportBranding? branding = null)
    {
        if (mergePermissions)
@@ -26,6 +91,8 @@ public class UserAccessHtmlExportService
            return BuildConsolidatedHtml(consolidated, entries, branding);
        }

+        var T = TranslationSource.Instance;
+
        // Compute stats
        var totalAccesses    = entries.Count;
        var usersAudited     = entries.Select(e => e.UserLogin).Distinct().Count();
@@ -41,7 +108,7 @@ public class UserAccessHtmlExportService
        sb.AppendLine("<head>");
        sb.AppendLine("<meta charset=\"UTF-8\">");
        sb.AppendLine("<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">");
-        sb.AppendLine("<title>User Access Audit Report</title>");
+        sb.AppendLine($"<title>{T["report.title.user_access"]}</title>");
        sb.AppendLine("<style>");
        sb.AppendLine(@"
 * { box-sizing: border-box; margin: 0; padding: 0; }
@@ -98,15 +165,15 @@ a:hover { text-decoration: underline; }
        // ── BODY ───────────────────────────────────────────────────────────────
        sb.AppendLine("<body>");
        sb.Append(BrandingHtmlHelper.BuildBrandingHeader(branding));
-        sb.AppendLine("<h1>User Access Audit Report</h1>");
+        sb.AppendLine($"<h1>{T["report.title.user_access"]}</h1>");

        // Stats cards
        sb.AppendLine("<div class=\"stats\">");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{totalAccesses}</div><div class=\"label\">Total Accesses</div></div>");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{usersAudited}</div><div class=\"label\">Users Audited</div></div>");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{sitesScanned}</div><div class=\"label\">Sites Scanned</div></div>");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{highPrivCount}</div><div class=\"label\">High Privilege</div></div>");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{externalCount}</div><div class=\"label\">External Users</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{totalAccesses}</div><div class=\"label\">{T["report.stat.total_accesses"]}</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{usersAudited}</div><div class=\"label\">{T["report.stat.users_audited"]}</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{sitesScanned}</div><div class=\"label\">{T["report.stat.sites_scanned"]}</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{highPrivCount}</div><div class=\"label\">{T["report.stat.high_privilege"]}</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{externalCount}</div><div class=\"label\">{T["report.stat.external_users"]}</div></div>");
        sb.AppendLine("</div>");

        // Per-user summary cards
@@ -123,34 +190,34 @@ a:hover { text-decoration: underline; }
            var cardClass = uHighPriv > 0 ? "user-card has-high-priv" : "user-card";

            sb.AppendLine($"  <div class=\"{cardClass}\">");
-            sb.AppendLine($"    <div class=\"user-name\">{uName}{(uIsExt ? " <span class=\"guest-badge\">Guest</span>" : "")}</div>");
+            sb.AppendLine($"    <div class=\"user-name\">{uName}{(uIsExt ? $" <span class=\"guest-badge\">{T["report.badge.guest"]}</span>" : "")}</div>");
            sb.AppendLine($"    <div class=\"user-stats\">{uLogin}</div>");
-            sb.AppendLine($"    <div class=\"user-stats\">{uTotal} accesses &bull; {uSites} site(s){(uHighPriv > 0 ? $" &bull; <span style=\"color:#dc2626\">{uHighPriv} high-priv</span>" : "")}</div>");
+            sb.AppendLine($"    <div class=\"user-stats\">{uTotal} {T["report.text.accesses"]} &bull; {uSites} {T["report.text.sites_parens"]}{(uHighPriv > 0 ? $" &bull; <span style=\"color:#dc2626\">{uHighPriv} {T["report.text.high_priv"]}</span>" : "")}</div>");
            sb.AppendLine("  </div>");
        }
        sb.AppendLine("</div>");

        // View toggle buttons
        sb.AppendLine("<div class=\"view-toggle\">");
-        sb.AppendLine("  <button id=\"btn-user\" class=\"active\" onclick=\"toggleView('user')\">By User</button>");
-        sb.AppendLine("  <button id=\"btn-site\" onclick=\"toggleView('site')\">By Site</button>");
+        sb.AppendLine($"  <button id=\"btn-user\" class=\"active\" onclick=\"toggleView('user')\">{T["report.view.by_user"]}</button>");
+        sb.AppendLine($"  <button id=\"btn-site\" onclick=\"toggleView('site')\">{T["report.view.by_site"]}</button>");
        sb.AppendLine("</div>");

        // Filter input
        sb.AppendLine("<div class=\"filter-wrap\">");
-        sb.AppendLine("  <input type=\"text\" id=\"filter\" placeholder=\"Filter results...\" oninput=\"filterTable()\" />");
+        sb.AppendLine($"  <input type=\"text\" id=\"filter\" placeholder=\"{T["report.filter.placeholder_results"]}\" oninput=\"filterTable()\" />");
        sb.AppendLine("</div>");

        // ── BY-USER VIEW ───────────────────────────────────────────────────────
        sb.AppendLine("<div id=\"view-user\" class=\"table-wrap\">");
        sb.AppendLine("<table id=\"tbl-user\">");
        sb.AppendLine("<thead><tr>");
-        sb.AppendLine("  <th onclick=\"sortTable('user',0)\">Site</th>");
-        sb.AppendLine("  <th onclick=\"sortTable('user',1)\">Object Type</th>");
-        sb.AppendLine("  <th onclick=\"sortTable('user',2)\">Object</th>");
-        sb.AppendLine("  <th onclick=\"sortTable('user',3)\">Permission Level</th>");
-        sb.AppendLine("  <th onclick=\"sortTable('user',4)\">Access Type</th>");
-        sb.AppendLine("  <th onclick=\"sortTable('user',5)\">Granted Through</th>");
+        sb.AppendLine($"  <th onclick=\"sortTable('user',0)\">{T["report.col.site"]}</th>");
+        sb.AppendLine($"  <th onclick=\"sortTable('user',1)\">{T["report.col.object_type"]}</th>");
+        sb.AppendLine($"  <th onclick=\"sortTable('user',2)\">{T["report.col.object"]}</th>");
+        sb.AppendLine($"  <th onclick=\"sortTable('user',3)\">{T["report.col.permission_level"]}</th>");
+        sb.AppendLine($"  <th onclick=\"sortTable('user',4)\">{T["report.col.access_type"]}</th>");
+        sb.AppendLine($"  <th onclick=\"sortTable('user',5)\">{T["report.col.granted_through"]}</th>");
        sb.AppendLine("</tr></thead>");
        sb.AppendLine("<tbody id=\"tbody-user\">");

@@ -161,10 +228,10 @@ a:hover { text-decoration: underline; }
            var uName    = HtmlEncode(ug.First().UserDisplayName);
            var uIsExt   = ug.First().IsExternalUser;
            var uCount   = ug.Count();
-            var guestBadge = uIsExt ? " <span class=\"guest-badge\">Guest</span>" : "";
+            var guestBadge = uIsExt ? $" <span class=\"guest-badge\">{T["report.badge.guest"]}</span>" : "";

            sb.AppendLine($"<tr class=\"group-header\" onclick=\"toggleGroup('{groupId}')\">");
-            sb.AppendLine($"  <td colspan=\"6\">{uName}{guestBadge} &mdash; {uCount} access(es)</td>");
+            sb.AppendLine($"  <td colspan=\"6\">{uName}{guestBadge} &mdash; {uCount} {T["report.text.access_es"]}</td>");
            sb.AppendLine("</tr>");

            foreach (var entry in ug)
@@ -173,10 +240,14 @@ a:hover { text-decoration: underline; }
                var accessBadge = AccessTypeBadge(entry.AccessType);
                var highIcon   = entry.IsHighPrivilege ? " &#9888;" : "";

+                var objectCell = IsRedundantObjectTitle(entry.SiteTitle, entry.ObjectTitle)
+                    ? "&mdash;"
+                    : HtmlEncode(entry.ObjectTitle);
+
                sb.AppendLine($"<tr data-group=\"{groupId}\">");
                sb.AppendLine($"  <td{rowClass}>{HtmlEncode(entry.SiteTitle)}</td>");
                sb.AppendLine($"  <td>{HtmlEncode(entry.ObjectType)}</td>");
-                sb.AppendLine($"  <td>{HtmlEncode(entry.ObjectTitle)}</td>");
+                sb.AppendLine($"  <td>{objectCell}</td>");
                sb.AppendLine($"  <td{rowClass}>{HtmlEncode(entry.PermissionLevel)}{highIcon}</td>");
                sb.AppendLine($"  <td>{accessBadge}</td>");
                sb.AppendLine($"  <td>{HtmlEncode(entry.GrantedThrough)}</td>");
@@ -192,12 +263,12 @@ a:hover { text-decoration: underline; }
        sb.AppendLine("<div id=\"view-site\" class=\"table-wrap hidden\">");
        sb.AppendLine("<table id=\"tbl-site\">");
        sb.AppendLine("<thead><tr>");
-        sb.AppendLine("  <th onclick=\"sortTable('site',0)\">User</th>");
-        sb.AppendLine("  <th onclick=\"sortTable('site',1)\">Object Type</th>");
-        sb.AppendLine("  <th onclick=\"sortTable('site',2)\">Object</th>");
-        sb.AppendLine("  <th onclick=\"sortTable('site',3)\">Permission Level</th>");
-        sb.AppendLine("  <th onclick=\"sortTable('site',4)\">Access Type</th>");
-        sb.AppendLine("  <th onclick=\"sortTable('site',5)\">Granted Through</th>");
+        sb.AppendLine($"  <th onclick=\"sortTable('site',0)\">{T["report.col.user"]}</th>");
+        sb.AppendLine($"  <th onclick=\"sortTable('site',1)\">{T["report.col.object_type"]}</th>");
+        sb.AppendLine($"  <th onclick=\"sortTable('site',2)\">{T["report.col.object"]}</th>");
+        sb.AppendLine($"  <th onclick=\"sortTable('site',3)\">{T["report.col.permission_level"]}</th>");
+        sb.AppendLine($"  <th onclick=\"sortTable('site',4)\">{T["report.col.access_type"]}</th>");
+        sb.AppendLine($"  <th onclick=\"sortTable('site',5)\">{T["report.col.granted_through"]}</th>");
        sb.AppendLine("</tr></thead>");
        sb.AppendLine("<tbody id=\"tbody-site\">");

@@ -210,7 +281,7 @@ a:hover { text-decoration: underline; }
            var sCount    = sg.Count();

            sb.AppendLine($"<tr class=\"group-header\" onclick=\"toggleGroup('{groupId}')\">");
-            sb.AppendLine($"  <td colspan=\"6\">{siteTitle} &mdash; {sCount} access(es)</td>");
+            sb.AppendLine($"  <td colspan=\"6\">{siteTitle} &mdash; {sCount} {T["report.text.access_es"]}</td>");
            sb.AppendLine("</tr>");

            foreach (var entry in sg)
@@ -218,12 +289,16 @@ a:hover { text-decoration: underline; }
                var rowClass   = entry.IsHighPrivilege ? " class=\"high-priv\"" : "";
                var accessBadge = AccessTypeBadge(entry.AccessType);
                var highIcon   = entry.IsHighPrivilege ? " &#9888;" : "";
-                var guestBadge = entry.IsExternalUser ? " <span class=\"guest-badge\">Guest</span>" : "";
+                var guestBadge = entry.IsExternalUser ? $" <span class=\"guest-badge\">{T["report.badge.guest"]}</span>" : "";
+
+                var objectCell = IsRedundantObjectTitle(entry.SiteTitle, entry.ObjectTitle)
+                    ? "&mdash;"
+                    : HtmlEncode(entry.ObjectTitle);

                sb.AppendLine($"<tr data-group=\"{groupId}\">");
                sb.AppendLine($"  <td>{HtmlEncode(entry.UserDisplayName)}{guestBadge}</td>");
                sb.AppendLine($"  <td>{HtmlEncode(entry.ObjectType)}</td>");
-                sb.AppendLine($"  <td>{HtmlEncode(entry.ObjectTitle)}</td>");
+                sb.AppendLine($"  <td>{objectCell}</td>");
                sb.AppendLine($"  <td{rowClass}>{HtmlEncode(entry.PermissionLevel)}{highIcon}</td>");
                sb.AppendLine($"  <td>{accessBadge}</td>");
                sb.AppendLine($"  <td>{HtmlEncode(entry.GrantedThrough)}</td>");
@@ -333,7 +408,7 @@ function sortTable(view, col) {
    public async Task WriteAsync(IReadOnlyList<UserAccessEntry> entries, string filePath, CancellationToken ct, bool mergePermissions = false, ReportBranding? branding = null)
    {
        var html = BuildHtml(entries, mergePermissions, branding);
-        await File.WriteAllTextAsync(filePath, html, new UTF8Encoding(encoderShouldEmitUTF8Identifier: false), ct);
+        await ExportFileWriter.WriteHtmlAsync(filePath, html, ct);
    }

    /// <summary>
@@ -345,6 +420,8 @@ function sortTable(view, col) {
        IReadOnlyList<UserAccessEntry> entries,
        ReportBranding? branding)
    {
+        var T = TranslationSource.Instance;
+
        // Stats computed from the original flat list for accurate counts
        var totalAccesses = entries.Count;
        var usersAudited  = entries.Select(e => e.UserLogin).Distinct().Count();
@@ -360,7 +437,7 @@ function sortTable(view, col) {
        sb.AppendLine("<head>");
        sb.AppendLine("<meta charset=\"UTF-8\">");
        sb.AppendLine("<meta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\">");
-        sb.AppendLine("<title>User Access Audit Report</title>");
+        sb.AppendLine($"<title>{T["report.title.user_access_consolidated"]}</title>");
        sb.AppendLine("<style>");
        sb.AppendLine(@"
 * { box-sizing: border-box; margin: 0; padding: 0; }
@@ -417,15 +494,15 @@ a:hover { text-decoration: underline; }
        // ── BODY ───────────────────────────────────────────────────────────────
        sb.AppendLine("<body>");
        sb.Append(BrandingHtmlHelper.BuildBrandingHeader(branding));
-        sb.AppendLine("<h1>User Access Audit Report</h1>");
+        sb.AppendLine($"<h1>{T["report.title.user_access_consolidated"]}</h1>");

        // Stats cards
        sb.AppendLine("<div class=\"stats\">");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{totalAccesses}</div><div class=\"label\">Total Accesses</div></div>");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{usersAudited}</div><div class=\"label\">Users Audited</div></div>");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{sitesScanned}</div><div class=\"label\">Sites Scanned</div></div>");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{highPrivCount}</div><div class=\"label\">High Privilege</div></div>");
-        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{externalCount}</div><div class=\"label\">External Users</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{totalAccesses}</div><div class=\"label\">{T["report.stat.total_accesses"]}</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{usersAudited}</div><div class=\"label\">{T["report.stat.users_audited"]}</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{sitesScanned}</div><div class=\"label\">{T["report.stat.sites_scanned"]}</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{highPrivCount}</div><div class=\"label\">{T["report.stat.high_privilege"]}</div></div>");
+        sb.AppendLine($"  <div class=\"stat-card\"><div class=\"value\">{externalCount}</div><div class=\"label\">{T["report.stat.external_users"]}</div></div>");
        sb.AppendLine("</div>");

        // Per-user summary cards (from original flat entries)
@@ -442,32 +519,32 @@ a:hover { text-decoration: underline; }
            var cardClass = uHighPriv > 0 ? "user-card has-high-priv" : "user-card";

            sb.AppendLine($"  <div class=\"{cardClass}\">");
-            sb.AppendLine($"    <div class=\"user-name\">{uName}{(uIsExt ? " <span class=\"guest-badge\">Guest</span>" : "")}</div>");
+            sb.AppendLine($"    <div class=\"user-name\">{uName}{(uIsExt ? $" <span class=\"guest-badge\">{T["report.badge.guest"]}</span>" : "")}</div>");
            sb.AppendLine($"    <div class=\"user-stats\">{uLogin}</div>");
-            sb.AppendLine($"    <div class=\"user-stats\">{uTotal} accesses &bull; {uSites} site(s){(uHighPriv > 0 ? $" &bull; <span style=\"color:#dc2626\">{uHighPriv} high-priv</span>" : "")}</div>");
+            sb.AppendLine($"    <div class=\"user-stats\">{uTotal} {T["report.text.accesses"]} &bull; {uSites} {T["report.text.sites_parens"]}{(uHighPriv > 0 ? $" &bull; <span style=\"color:#dc2626\">{uHighPriv} {T["report.text.high_priv"]}</span>" : "")}</div>");
            sb.AppendLine("  </div>");
        }
        sb.AppendLine("</div>");

        // View toggle — only By User (By Site is suppressed for consolidated view)
        sb.AppendLine("<div class=\"view-toggle\">");
-        sb.AppendLine("  <button id=\"btn-user\" class=\"active\">By User</button>");
+        sb.AppendLine($"  <button id=\"btn-user\" class=\"active\">{T["report.view.by_user"]}</button>");
        sb.AppendLine("</div>");

        // Filter input
        sb.AppendLine("<div class=\"filter-wrap\">");
-        sb.AppendLine("  <input type=\"text\" id=\"filter\" placeholder=\"Filter results...\" oninput=\"filterTable()\" />");
+        sb.AppendLine($"  <input type=\"text\" id=\"filter\" placeholder=\"{T["report.filter.placeholder_results"]}\" oninput=\"filterTable()\" />");
        sb.AppendLine("</div>");

        // ── CONSOLIDATED BY-USER TABLE ────────────────────────────────────────
        sb.AppendLine("<div id=\"view-user\" class=\"table-wrap\">");
        sb.AppendLine("<table id=\"tbl-user\">");
        sb.AppendLine("<thead><tr>");
-        sb.AppendLine("  <th>User</th>");
-        sb.AppendLine("  <th>Permission Level</th>");
-        sb.AppendLine("  <th>Access Type</th>");
-        sb.AppendLine("  <th>Granted Through</th>");
-        sb.AppendLine("  <th>Sites</th>");
+        sb.AppendLine($"  <th>{T["report.col.user"]}</th>");
+        sb.AppendLine($"  <th>{T["report.col.permission_level"]}</th>");
+        sb.AppendLine($"  <th>{T["report.col.access_type"]}</th>");
+        sb.AppendLine($"  <th>{T["report.col.granted_through"]}</th>");
+        sb.AppendLine($"  <th>{T["report.col.sites"]}</th>");
        sb.AppendLine("</tr></thead>");
        sb.AppendLine("<tbody id=\"tbody-user\">");

@@ -486,10 +563,10 @@ a:hover { text-decoration: underline; }
            var cuName     = HtmlEncode(cug.First().UserDisplayName);
            var cuIsExt    = cug.First().IsExternalUser;
            var cuCount    = cug.Count();
-            var guestBadge = cuIsExt ? " <span class=\"guest-badge\">Guest</span>" : "";
+            var guestBadge = cuIsExt ? $" <span class=\"guest-badge\">{T["report.badge.guest"]}</span>" : "";

            sb.AppendLine($"<tr class=\"group-header\" onclick=\"toggleGroup('{groupId}')\">");
-            sb.AppendLine($"  <td colspan=\"5\">{cuName}{guestBadge} &mdash; {cuCount} permission(s)</td>");
+            sb.AppendLine($"  <td colspan=\"5\">{cuName}{guestBadge} &mdash; {cuCount} {T["report.text.permissions_parens"]}</td>");
            sb.AppendLine("</tr>");

            foreach (var entry in cug)
@@ -508,7 +585,7 @@ a:hover { text-decoration: underline; }
                {
                    // Single location — inline site title + object title
                    var loc0 = entry.Locations[0];
-                    var locLabel = string.IsNullOrEmpty(loc0.ObjectTitle)
+                    var locLabel = IsRedundantObjectTitle(loc0.SiteTitle, loc0.ObjectTitle)
                        ? HtmlEncode(loc0.SiteTitle)
                        : $"{HtmlEncode(loc0.SiteTitle)} &rsaquo; {HtmlEncode(loc0.ObjectTitle)}";
                    sb.AppendLine($"  <td>{locLabel}</td>");
@@ -518,13 +595,13 @@ a:hover { text-decoration: underline; }
                {
                    // Multiple locations — expandable badge
                    var currentLocId = $"loc{locIdx++}";
-                    sb.AppendLine($"  <td><span class=\"badge\" onclick=\"toggleGroup('{currentLocId}')\" style=\"cursor:pointer\">{entry.LocationCount} sites</span></td>");
+                    sb.AppendLine($"  <td><span class=\"badge\" onclick=\"toggleGroup('{currentLocId}')\" style=\"cursor:pointer\">{entry.LocationCount} {TranslationSource.Instance["report.text.sites_unit"]}</span></td>");
                    sb.AppendLine("</tr>");

                    // Hidden sub-rows — one per location
                    foreach (var loc in entry.Locations)
                    {
-                        var subLabel = string.IsNullOrEmpty(loc.ObjectTitle)
+                        var subLabel = IsRedundantObjectTitle(loc.SiteTitle, loc.ObjectTitle)
                            ? $"<a href=\"{HtmlEncode(loc.SiteUrl)}\">{HtmlEncode(loc.SiteTitle)}</a>"
                            : $"<a href=\"{HtmlEncode(loc.SiteUrl)}\">{HtmlEncode(loc.SiteTitle)}</a> &rsaquo; {HtmlEncode(loc.ObjectTitle)}";
                        sb.AppendLine($"<tr data-group=\"{currentLocId}\" style=\"display:none\">");
@@ -591,13 +668,31 @@ function toggleGroup(id) {
    }

    /// <summary>Returns a colored badge span for the given access type.</summary>
-    private static string AccessTypeBadge(AccessType accessType) => accessType switch
+    private static string AccessTypeBadge(AccessType accessType)
    {
-        AccessType.Direct    => "<span class=\"badge access-direct\">Direct</span>",
-        AccessType.Group     => "<span class=\"badge access-group\">Group</span>",
-        AccessType.Inherited => "<span class=\"badge access-inherited\">Inherited</span>",
-        _                    => $"<span class=\"badge\">{HtmlEncode(accessType.ToString())}</span>"
-    };
+        var T = TranslationSource.Instance;
+        return accessType switch
+        {
+            AccessType.Direct    => $"<span class=\"badge access-direct\">{T["report.badge.direct"]}</span>",
+            AccessType.Group     => $"<span class=\"badge access-group\">{T["report.badge.group"]}</span>",
+            AccessType.Inherited => $"<span class=\"badge access-inherited\">{T["report.badge.inherited"]}</span>",
+            _                    => $"<span class=\"badge\">{HtmlEncode(accessType.ToString())}</span>"
+        };
+    }
+
+    /// <summary>
+    /// Returns true when the ObjectTitle adds no information beyond the SiteTitle:
+    /// empty, identical (case-insensitive), or one is a whitespace-trimmed duplicate
+    /// of the other. Used to collapse "All Company &rsaquo; All Company" to "All Company".
+    /// </summary>
+    private static bool IsRedundantObjectTitle(string siteTitle, string objectTitle)
+    {
+        if (string.IsNullOrWhiteSpace(objectTitle)) return true;
+        return string.Equals(
+            (siteTitle ?? string.Empty).Trim(),
+            objectTitle.Trim(),
+            StringComparison.OrdinalIgnoreCase);
+    }

    /// <summary>Minimal HTML encoding for text content and attribute values.</summary>
    private static string HtmlEncode(string value)