Add retroactive cleanup for the existing database

The privacy filter only catches new messages. Two new MessageStore methods support a one-shot retroactive sweep: GetMessageCountsByChatType returns a (ChatType, count) snapshot so the UI can preview the impact, and CleanupRetainOnly hard-deletes everything outside the supplied allowlist and runs VACUUM to reclaim disk space. The Privacy tab gains a new section with a refresh-preview button, a keep/delete summary, a per-channel breakdown tree, and a Ctrl+Shift confirm. The cleanup runs on a background thread so a 800+ MB VACUUM does not block the settings UI; tabs are rebuilt via the framework thread once the delete finishes. The cleanup deliberately uses the saved Plugin.Config whitelist (not unsaved Mutable edits) so it stays consistent with the prospective filter.
2026-05-01 18:34:28 +02:00
parent 465aadbb1a
commit 2401ea5864
3 changed files with 196 additions and 2 deletions
@@ -310,6 +310,53 @@ internal class MessageStore : IDisposable
        PerformMaintenance();
    }

+    /// <summary>
+    /// Returns a (ChatType, count) snapshot over non-deleted messages.
+    /// Used by the Privacy tab to preview the impact of a retroactive
+    /// cleanup before the user confirms.
+    /// </summary>
+    internal Dictionary<int, long> GetMessageCountsByChatType()
+    {
+        var result = new Dictionary<int, long>();
+        using var cmd = Connection.CreateCommand();
+        cmd.CommandText = "SELECT ChatType, COUNT(*) FROM messages WHERE deleted = false GROUP BY ChatType;";
+        cmd.CommandTimeout = 120;
+        using var reader = cmd.ExecuteReader();
+        while (reader.Read())
+        {
+            var chatType = reader.GetInt32(0);
+            var count = reader.GetInt64(1);
+            result[chatType] = count;
+        }
+        return result;
+    }
+
+    /// <summary>
+    /// Hard-deletes every message whose ChatType is not in the supplied
+    /// allowlist, then VACUUMs the database to reclaim disk space.
+    /// Returns the number of rows deleted.
+    /// </summary>
+    internal long CleanupRetainOnly(IReadOnlyCollection<int> allowedTypes)
+    {
+        if (allowedTypes.Count == 0)
+        {
+            // Defensive: refuse a "delete everything" disguised as a filter.
+            // Use ClearMessages() if a full wipe is actually intended.
+            throw new InvalidOperationException("CleanupRetainOnly requires at least one allowed ChatType. Use ClearMessages for a full wipe.");
+        }
+
+        var inList = string.Join(",", allowedTypes);
+        long deleted;
+        using (var cmd = Connection.CreateCommand())
+        {
+            cmd.CommandText = $"DELETE FROM messages WHERE ChatType NOT IN ({inList});";
+            cmd.CommandTimeout = 600;
+            deleted = cmd.ExecuteNonQuery();
+        }
+        PerformMaintenance();
+        return deleted;
+    }
+
    internal void PerformMaintenance()
    {
        Connection.Execute(@"