Initial commit

Core/Models/PermissionSummary.cs

@@ -0,0 +1,33 @@
+namespace SharepointToolbox.Web.Core.Models;
+
+public record PermissionSummary(
+    string Label,
+    RiskLevel RiskLevel,
+    int Count,
+    int DistinctUsers
+);
+
+public static class PermissionSummaryBuilder
+{
+    private static readonly Dictionary<RiskLevel, string> Labels = new()
+    {
+        [RiskLevel.High]     = "High Risk",
+        [RiskLevel.Medium]   = "Medium Risk",
+        [RiskLevel.Low]      = "Low Risk",
+        [RiskLevel.ReadOnly] = "Read Only",
+    };
+
+    public static IReadOnlyList<PermissionSummary> Build(IEnumerable<SimplifiedPermissionEntry> entries)
+    {
+        var grouped = entries.GroupBy(e => e.RiskLevel).ToDictionary(g => g.Key, g => g.ToList());
+        return Enum.GetValues<RiskLevel>().Select(level =>
+        {
+            var items = grouped.GetValueOrDefault(level, new List<SimplifiedPermissionEntry>());
+            var distinctUsers = items
+                .SelectMany(e => e.UserLogins.Split(';', StringSplitOptions.RemoveEmptyEntries))
+                .Select(u => u.Trim()).Where(u => u.Length > 0)
+                .Distinct(StringComparer.OrdinalIgnoreCase).Count();
+            return new PermissionSummary(Labels[level], level, items.Count, distinctUsers);
+        }).ToList();
+    }
+}