import { createClient } from 'redis';
import pkg from 'pg';
const { Pool } = pkg;

export interface DatabaseConfig {
  redis: {
    url: string;
    maxRetriesPerRequest: number;
  };
  postgres: {
    host: string;
    port: number;
    database: string;
    user: string;
    password: string;
    max: number;
  };
}

export const databaseConfig: DatabaseConfig = {
  redis: {
    url: process.env.REDIS_URL || 'redis://localhost:6379',
    maxRetriesPerRequest: 3,
  },
  postgres: {
    host: process.env.POSTGRES_HOST || 'localhost',
    port: parseInt(process.env.POSTGRES_PORT || '5432'),
    database: process.env.POSTGRES_DB || 'gaplace',
    user: process.env.POSTGRES_USER || 'gaplace',
    password: process.env.POSTGRES_PASSWORD || 'password',
    max: 20,
  },
};

// Redis client
export const redisClient = createClient({
  url: databaseConfig.redis.url,
});

redisClient.on('error', (err) => {
  console.error('Redis Client Error:', err);
});

redisClient.on('connect', () => {
  console.log('✅ Connected to Redis');
});

// PostgreSQL client
export const pgPool = new Pool(databaseConfig.postgres);

pgPool.on('error', (err) => {
  console.error('PostgreSQL Pool Error:', err);
});

export async function initializeDatabase(): Promise<void> {
  try {
    // Connect to Redis
    await redisClient.connect();
    
    // Test PostgreSQL connection
    const client = await pgPool.connect();
    console.log('✅ Connected to PostgreSQL');
    client.release();
    
    // Create tables if they don't exist
    await createTables();
  } catch (error) {
    console.error('❌ Database initialization failed:', error);
    throw error;
  }
}

async function createTables(): Promise<void> {
  const client = await pgPool.connect();
  
  try {
    await client.query(`
      CREATE TABLE IF NOT EXISTS users (
        id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
        username VARCHAR(50) UNIQUE NOT NULL,
        email VARCHAR(255) UNIQUE,
        password_hash VARCHAR(255),
        avatar_url TEXT,
        is_guest BOOLEAN DEFAULT TRUE,
        created_at TIMESTAMP DEFAULT NOW(),
        last_seen TIMESTAMP DEFAULT NOW()
      );
    `);

    await client.query(`
      CREATE TABLE IF NOT EXISTS canvases (
        id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
        name VARCHAR(100) NOT NULL,
        width INTEGER NOT NULL DEFAULT 1000,
        height INTEGER NOT NULL DEFAULT 1000,
        chunk_size INTEGER NOT NULL DEFAULT 64,
        is_public BOOLEAN DEFAULT TRUE,
        created_by UUID REFERENCES users(id),
        created_at TIMESTAMP DEFAULT NOW(),
        updated_at TIMESTAMP DEFAULT NOW()
      );
    `);

    await client.query(`
      CREATE TABLE IF NOT EXISTS user_sessions (
        id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
        user_id UUID REFERENCES users(id),
        canvas_id UUID REFERENCES canvases(id),
        session_token VARCHAR(255) UNIQUE NOT NULL,
        is_active BOOLEAN DEFAULT TRUE,
        last_activity TIMESTAMP DEFAULT NOW(),
        created_at TIMESTAMP DEFAULT NOW()
      );
    `);

    await client.query(`
      CREATE INDEX IF NOT EXISTS idx_users_username ON users(username);
      CREATE INDEX IF NOT EXISTS idx_canvases_public ON canvases(is_public);
      CREATE INDEX IF NOT EXISTS idx_sessions_active ON user_sessions(is_active, last_activity);
    `);

    console.log('✅ Database tables created/verified');
  } finally {
    client.release();
  }
}