@page "/bulk-members"
@attribute [Authorize]
@inject IUserSessionService Session
@inject IUserContextAccessor UserContext
@inject ISessionManager SessionMgr
@inject IElevationCoordinator Elevation
@inject IBulkMemberService BulkSvc
@inject ICsvValidationService CsvValidation
@inject BulkResultCsvExportService ExportSvc
@inject WebExportService WebExport
@rendermode InteractiveServer

<h1 class="page-title">Bulk Members</h1>
<p class="page-subtitle">Add users to SharePoint groups from a CSV file.</p>

@if (!Session.HasProfile) { <NoProfilePrompt /> return; }
@if (UserContext.Role < UserRole.TechN1) { <WriteGuard /> return; }

<div class="card">
    <SitePicker Profile="Session.CurrentProfile!" @bind-SelectedSites="_sites" Single="true" />
    <div class="form-group">
        <label class="form-label">CSV File (GroupName, GroupUrl, Email, Role)</label>
        <InputFile OnChange="LoadFile" accept=".csv" class="form-input" />
    </div>

    @if (_rows.Count > 0)
    {
        <div class="alert alert-info mt-8">
            @_rows.Count(r => r.IsValid) valid rows, @_rows.Count(r => !r.IsValid) errors.
        </div>
        <div class="data-table-wrap" style="max-height:200px;overflow-y:auto">
            <table class="data-table">
                <thead><tr><th>Group</th><th>Email</th><th>Role</th><th>Status</th></tr></thead>
                <tbody>
                    @foreach (var row in _rows.Take(50))
                    {
                        <tr class="@(row.IsValid ? "val-valid" : "val-error")">
                            <td>@(row.Record?.GroupName ?? "—")</td>
                            <td>@(row.Record?.Email ?? "—")</td>
                            <td>@(row.Record?.Role ?? "—")</td>
                            <td>@(row.IsValid ? "✓" : string.Join("; ", row.Errors))</td>
                        </tr>
                    }
                </tbody>
            </table>
        </div>
    }

    <div class="flex-row mt-8">
        <button class="btn btn-primary" @onclick="RunBulk" disabled="@(_running || _rows.Count == 0 || _rows.All(r => !r.IsValid))">
            @(_running ? "Processing…" : "Add Members")
        </button>
        @if (_running) { <button class="btn btn-secondary" @onclick="Cancel">Cancel</button> }
    </div>
    <ProgressPanel IsRunning="_running" StatusMessage="@_status" Current="_current" Total="_total" />
</div>

@if (!string.IsNullOrEmpty(_error)) { <div class="alert alert-error">@_error</div> }

@if (_summary != null)
{
    <div class="card">
        <div class="alert @(_summary.HasFailures ? "alert-warn" : "alert-success")">
            Processed: @_summary.SuccessCount / @_summary.TotalCount. Failures: @_summary.FailedCount
        </div>
        @if (_summary.HasFailures)
        {
            <button class="btn btn-secondary btn-sm mt-8" @onclick="ExportErrors">Export Errors CSV</button>
        }
    </div>
}

@code {
    private List<SiteInfo> _sites = new();
    private List<CsvValidationRow<BulkMemberRow>> _rows = new();
    private bool _running; private string _status = string.Empty, _error = string.Empty;
    private int _current, _total;
    private BulkOperationSummary<BulkMemberRow>? _summary;
    private CancellationTokenSource? _cts;

    private async Task LoadFile(InputFileChangeEventArgs e)
    {
        _rows.Clear();
        var file = e.File;
        using var stream = file.OpenReadStream(maxAllowedSize: 10 * 1024 * 1024);
        _rows = CsvValidation.ParseAndValidateMembers(stream);
    }

    private async Task RunBulk()
    {
        _error = string.Empty; _summary = null; _running = true;
        _cts = new CancellationTokenSource();
        var validRows = _rows.Where(r => r.IsValid && r.Record != null).Select(r => r.Record!).ToList();
        var siteUrl = _sites.FirstOrDefault()?.Url;
        if (string.IsNullOrWhiteSpace(siteUrl)) { _error = "Please select a site."; _running = false; return; }
        var progress = new Progress<OperationProgress>(p => { _status = p.Message; _current = p.Current; _total = p.Total; InvokeAsync(StateHasChanged); });
        try
        {
            _summary = await Elevation.RunAsync(async c =>
            {
                var ctx = await SessionMgr.GetOrCreateContextAsync(siteUrl, Session.CurrentProfile!, c);
                return await BulkSvc.AddMembersAsync(ctx, Session.CurrentProfile!, validRows, progress, c);
            }, _cts.Token);
            _status = $"Complete: {_summary.SuccessCount} added, {_summary.FailedCount} failed.";
        }
        catch (OperationCanceledException) { _status = "Cancelled."; }
        catch (Exception ex) { _error = ex.Message; }
        finally { _running = false; await InvokeAsync(StateHasChanged); }
    }

    private void Cancel() => _cts?.Cancel();
    private async Task ExportErrors()
    {
        if (_summary == null) return;
        var csv = ExportSvc.BuildFailedItemsCsv(_summary.Results.ToList());
        await WebExport.DownloadCsvAsync(csv, $"bulk_members_errors_{DateTime.Now:yyyyMMdd_HHmmss}.csv");
    }
}