Enhance video library management in PLib by introducing folder change tracking and improving video item metadata handling. Update IVideoRepository to include a method for loading video items with labels. Revise VideoPlayerViewModel to manage playback progress and integrate new UI elements for displaying watched status and resume options. Update MainWindowViewModel to observe folder changes for automatic rescanning. Enhance README.md to document these new features and usage instructions.

src/PLib.Infrastructure/Persistence/DatabaseInitializer.cs

@@ -8,10 +8,6 @@ namespace PLib.Infrastructure.Persistence;
 /// <summary>
 /// Brings the local database up to date before the first window is shown.
 /// </summary>
-/// <remarks>
-/// While the schema is still moving we create it from the model. Once the shape settles this
-/// becomes <c>MigrateAsync</c> plus a checked-in migration history.
-/// </remarks>
 public sealed class DatabaseInitializer(
     IServiceScopeFactory scopeFactory,
     ILogger<DatabaseInitializer> logger) : IHostedService
@@ -21,9 +17,55 @@ public sealed class DatabaseInitializer(
         await using var scope = scopeFactory.CreateAsyncScope();
         var dbContext = scope.ServiceProvider.GetRequiredService<LibraryDbContext>();
 
-        var created = await dbContext.Database.EnsureCreatedAsync(cancellationToken);
-        logger.LogInformation("Library database ready (created: {Created})", created);
+        if (await IsPreMigrationDatabaseAsync(dbContext, cancellationToken))
+        {
+            // Earlier builds created the schema straight from the model, so there is no
+            // migration history to continue from and no honest way to baseline one — the
+            // columns a baseline would claim exist do not. The database is a cache over the
+            // file system, so throwing it away costs one rescan; poster frames are keyed by
+            // file and survive untouched.
+            logger.LogWarning("Replacing a database created before migrations were introduced");
+            await dbContext.Database.EnsureDeletedAsync(cancellationToken);
+        }
+
+        var pending = await dbContext.Database.GetPendingMigrationsAsync(cancellationToken);
+        var pendingCount = pending.Count();
+
+        if (pendingCount > 0)
+        {
+            logger.LogInformation("Applying {Count} database migration(s)", pendingCount);
+        }
+
+        await dbContext.Database.MigrateAsync(cancellationToken);
+        logger.LogInformation("Library database ready");
     }
 
     public Task StopAsync(CancellationToken cancellationToken) => Task.CompletedTask;
+
+    /// <summary>
+    /// True when the file holds a schema but no migration history — the shape earlier
+    /// versions left behind.
+    /// </summary>
+    private static async Task<bool> IsPreMigrationDatabaseAsync(
+        LibraryDbContext dbContext,
+        CancellationToken cancellationToken)
+    {
+        if (!await dbContext.Database.CanConnectAsync(cancellationToken))
+        {
+            return false;
+        }
+
+        var applied = await dbContext.Database.GetAppliedMigrationsAsync(cancellationToken);
+
+        if (applied.Any())
+        {
+            return false;
+        }
+
+        var tables = await dbContext.Database
+            .SqlQuery<string>($"SELECT name FROM sqlite_master WHERE type = 'table' AND name = 'Videos'")
+            .ToListAsync(cancellationToken);
+
+        return tables.Count > 0;
+    }
 }