import Database from "better-sqlite3";

const db = new Database("./data/database.sqlite");

console.log("🔄 Migrating database to username-based authentication...\n");

try {
    // Check current table structure
    const tableInfo = db.prepare("PRAGMA table_info(users)").all();
    console.log("Current users table columns:");
    tableInfo.forEach(col => console.log(`  - ${col.name}: ${col.type}`));
    
    const hasUsername = tableInfo.some(col => col.name === 'username');
    const hasEmail = tableInfo.some(col => col.name === 'email');
    
    if (hasUsername) {
        console.log("✅ Username column already exists!");
    } else if (hasEmail) {
        console.log("\n📝 Adding username column...");
        
        // Add username column
        db.exec(`ALTER TABLE users ADD COLUMN username TEXT;`);
        console.log("✅ Username column added");
        
        // Copy email data to username for existing users
        console.log("📋 Migrating existing email data to username...");
        const result = db.exec(`UPDATE users SET username = email WHERE username IS NULL;`);
        console.log("✅ Data migrated");
        
        // Create unique index on username
        console.log("🔍 Creating unique index on username...");
        try {
            db.exec(`CREATE UNIQUE INDEX idx_users_username_unique ON users(username);`);
            console.log("✅ Unique index created");
        } catch (e) {
            console.log("ℹ️ Index already exists or couldn't be created:", e.message);
        }
        
        // Verify migration
        console.log("\n🔍 Verifying migration...");
        const users = db.prepare("SELECT id, name, username, email FROM users LIMIT 3").all();
        console.log("Sample users after migration:");
        users.forEach(user => {
            console.log(`  - ${user.name}: username="${user.username}", email="${user.email || 'NULL'}"`);
        });
        
        console.log("\n✅ Migration completed successfully!");
        console.log("ℹ️  You can now log in using usernames instead of emails");
        
    } else {
        console.log("❌ Neither username nor email column found. Database may be corrupted.");
        process.exit(1);
    }
    
} catch (error) {
    console.error("❌ Migration failed:", error.message);
    process.exit(1);
} finally {
    db.close();
}