Added back Remote Cursors

server/database.ts

@@ -28,29 +28,93 @@ db.exec(`
     x INTEGER NOT NULL,
     y INTEGER NOT NULL,
     color TEXT NOT NULL,
+    user_id INTEGER,
     updated_at DATETIME DEFAULT CURRENT_TIMESTAMP,
-    PRIMARY KEY (x, y)
+    PRIMARY KEY (x, y),
+    FOREIGN KEY (user_id) REFERENCES users(id)
   );
 
   CREATE INDEX IF NOT EXISTS idx_pixels_updated ON pixels(updated_at);
 `);
 
+const tableInfo = db.pragma('table_info(pixels)') as { name: string }[];
+const hasUserId = tableInfo.some(col => col.name === 'user_id');
+if (!hasUserId) {
+  db.exec('ALTER TABLE pixels ADD COLUMN user_id INTEGER REFERENCES users(id)');
+}
+
+const indexes = db.pragma('index_list(pixels)') as { name: string }[];
+const hasIndex = indexes.some(idx => idx.name === 'idx_pixels_updated');
+if (!hasIndex) {
+  db.exec('CREATE INDEX idx_pixels_updated ON pixels(updated_at)');
+}
+
 export function generateUserId(): string {
   return `user_${Date.now()}_${Math.random().toString(36).substr(2, 9)}`;
 }
 
-export function upsertPixels(pixels: { x: number; y: number; color: string }[]): void {
+function isValidColor(color: string): boolean {
+  return /^#[0-9A-Fa-f]{6}$/.test(color);
+}
+
+export function validatePixel(pixel: { x: number; y: number; color: string }): string | null {
+  if (!Number.isInteger(pixel.x) || pixel.x < -1000000 || pixel.x > 1000000) {
+    return 'Invalid x coordinate';
+  }
+  if (!Number.isInteger(pixel.y) || pixel.y < -1000000 || pixel.y > 1000000) {
+    return 'Invalid y coordinate';
+  }
+  if (!isValidColor(pixel.color)) {
+    return 'Invalid color format';
+  }
+  return null;
+}
+
+export function upsertPixelsWithConflictResolution(
+  pixels: { x: number; y: number; color: string; userId?: number }[],
+  clientTimestamp: number
+): { saved: number; conflicts: number } {
+  const getStmt = db.prepare('SELECT updated_at FROM pixels WHERE x = ? AND y = ?');
   const stmt = db.prepare(
-    'INSERT OR REPLACE INTO pixels (x, y, color, updated_at) VALUES (?, ?, ?, CURRENT_TIMESTAMP)'
+    'INSERT OR REPLACE INTO pixels (x, y, color, user_id, updated_at) VALUES (?, ?, ?, ?, CURRENT_TIMESTAMP)'
   );
-  
+
+  let saved = 0;
+  let conflicts = 0;
+
   const transaction = db.transaction((pixels: any[]) => {
     for (const pixel of pixels) {
-      stmt.run(pixel.x, pixel.y, pixel.color);
+      try {
+        const existing = getStmt.get(pixel.x, pixel.y) as { updated_at: string } | undefined;
+        if (existing) {
+          const existingTime = new Date(existing.updated_at).getTime();
+          if (clientTimestamp && existingTime > clientTimestamp) {
+            conflicts++;
+            continue;
+          }
+        }
+        stmt.run(pixel.x, pixel.y, pixel.color, pixel.userId || null);
+        saved++;
+      } catch (err) {
+        console.error('Error upserting pixel:', err);
+      }
     }
   });
-  
+
   transaction(pixels);
+  return { saved, conflicts };
+}
+
+export function getPixelsInRange(
+  minX: number,
+  maxX: number,
+  minY: number,
+  maxY: number
+): { x: number; y: number; color: string }[] {
+  const stmt = db.prepare(
+    'SELECT x, y, color FROM pixels WHERE x >= ? AND x <= ? AND y >= ? AND y <= ? ORDER BY x, y'
+  );
+  return stmt.all(minX, maxX, minY, maxY) as { x: number; y: number; color: string }[];
 }
 
 export function getAllPixels(): { x: number; y: number; color: string }[] {