Feature: Integrate Discover component with improved capabilities - Added category filters and personalization features - Implemented support for multiple languages and search engines - Added preferences saving - Fixed Chinese language search issue

src/lib/db/migrate.ts

@@ -0,0 +1,61 @@
+import db from './index';
+import { userPreferences } from './schema';
+import { sql } from 'drizzle-orm';
+
+/**
+ * Run database migrations to ensure schema is up to date.
+ * This is designed to run once at application startup.
+ */
+export async function runMigrations() {
+  console.log('[DB Migration] Checking database schema...');
+  
+  try {
+    // Check if userPreferences table exists
+    const tableExists = await checkIfTableExists('userPreferences');
+    
+    if (!tableExists) {
+      console.log('[DB Migration] Creating userPreferences table...');
+      await createUserPreferencesTable();
+      console.log('[DB Migration] userPreferences table created successfully.');
+    } else {
+      console.log('[DB Migration] userPreferences table already exists.');
+    }
+    
+    console.log('[DB Migration] Database schema is up to date.');
+  } catch (error) {
+    console.error('[DB Migration] Error during migration:', error);
+    // Don't throw the error - we want the application to continue even if migration fails
+  }
+}
+
+/**
+ * Check if a table exists in the database
+ */
+async function checkIfTableExists(tableName: string): Promise<boolean> {
+  const result = db.$client.prepare(`
+    SELECT name FROM sqlite_master 
+    WHERE type='table' AND name=?;
+  `).all(tableName);
+  
+  return result.length > 0;
+}
+
+/**
+ * Create the userPreferences table using the schema definition
+ */
+async function createUserPreferencesTable() {
+  // Create the table using a raw SQL query based on our schema
+  db.$client.prepare(`
+    CREATE TABLE userPreferences (
+      id INTEGER PRIMARY KEY,
+      userId TEXT NOT NULL UNIQUE,
+      categories TEXT DEFAULT '[]' NOT NULL,
+      languages TEXT DEFAULT '[]' NOT NULL,
+      createdAt TEXT NOT NULL,
+      updatedAt TEXT NOT NULL
+    );
+  `).run();
+}
+
+// Run migrations automatically when this module is imported
+runMigrations();