3RESIT/backend/app/utils/database.js

import pg from "pg";

// Create a connection pool instead of individual connections
const pool = new pg.Pool({
    user: process.env.POSTGRES_USER,
    password: process.env.POSTGRES_PASSWORD,
    host: process.env.POSTGRES_HOST,
    database: process.env.POSTGRES_DB,
    port: 5432,
    max: 30, // Increased maximum number of connections in the pool
    idleTimeoutMillis: 30000, // Close idle connections after 30 seconds
    connectionTimeoutMillis: 10000, // Increased timeout to 10 seconds
    acquireTimeoutMillis: 10000, // Wait up to 10 seconds for a connection
});

export async function getClient() {
    // Use pool.connect() instead of creating new clients
    return await pool.connect();
}

// Graceful shutdown
process.on('SIGINT', () => {
    pool.end(() => {
        console.log('Pool has ended');
        process.exit(0);
    });
});

export async function initDb() {

    const client = await getClient();

    try {
        let query = `CREATE TABLE IF NOT EXISTS users (
            id SERIAL PRIMARY KEY,
            email VARCHAR(255),
            username VARCHAR(255) NOT NULL, 
            password VARCHAR(255),
            picture VARCHAR(255),
            is_verified BOOLEAN NOT NULL DEFAULT FALSE,
            github_id VARCHAR(255) UNIQUE,
            created_at TIMESTAMP NOT NULL DEFAULT NOW(),
            updated_at TIMESTAMP NOT NULL DEFAULT NOW()
        );`;
        await client.query(query);

        query = `CREATE TABLE IF NOT EXISTS channels (
            id SERIAL PRIMARY KEY,
            name VARCHAR(255) NOT NULL,
            description TEXT NOT NULL,
            owner INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE
        )`
        await client.query(query);

        query = `CREATE TABLE IF NOT EXISTS videos (
           id SERIAL PRIMARY KEY,
           title VARCHAR(255) NOT NULL,
            thumbnail VARCHAR(255) NOT NULL,
            description TEXT NOT NULL,
            channel INTEGER NOT NULL REFERENCES channels(id) ON DELETE CASCADE,
            visibility VARCHAR(50) NOT NULL DEFAULT 'public',
            file VARCHAR(255) NOT NULL,
            slug VARCHAR(255) NOT NULL,
            format VARCHAR(50) NOT NULL,
            release_date TIMESTAMP NOT NULL DEFAULT NOW()
            );`;
        await client.query(query);

        query = `CREATE TABLE IF NOT EXISTS comments
                 (
                    id SERIAL PRIMARY KEY,
                    content TEXT NOT NULL,
                    author INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
                    video INTEGER NOT NULL REFERENCES videos(id) ON DELETE CASCADE,
                    created_at TIMESTAMP NOT NULL DEFAULT NOW()
                 )`;
        await client.query(query);

        query = `CREATE TABLE IF NOT EXISTS likes (
                    id SERIAL PRIMARY KEY,
                    owner INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
                    video INTEGER NOT NULL REFERENCES videos(id) ON DELETE CASCADE,
                    created_at TIMESTAMP NOT NULL DEFAULT NOW()
                 );`;
        await client.query(query);

        query = `CREATE TABLE IF NOT EXISTS playlists (
            id SERIAL PRIMARY KEY,
            name VARCHAR(255) NOT NULL,
            owner INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE
        )`;
        await client.query(query);

        query = `CREATE TABLE IF NOT EXISTS playlist_elements (
            id SERIAL PRIMARY KEY,
            video INTEGER NOT NULL REFERENCES videos(id) ON DELETE CASCADE,
            playlist INTEGER NOT NULL REFERENCES playlists(id) ON DELETE CASCADE
        )`;
        await client.query(query);

        query = `CREATE TABLE IF NOT EXISTS subscriptions (
            id SERIAL PRIMARY KEY,
            channel INTEGER NOT NULL REFERENCES channels(id) ON DELETE CASCADE,
            owner INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE
        )`;
        await client.query(query);

        query = `CREATE TABLE IF NOT EXISTS tags(
            id SERIAL PRIMARY KEY,
            name VARCHAR(255) NOT NULL,
            usage_count INTEGER NOT NULL DEFAULT 0
        )`;
        await client.query(query);

        query = `CREATE TABLE IF NOT EXISTS video_tags (
            video INTEGER NOT NULL REFERENCES videos(id) ON DELETE CASCADE,
            tag INTEGER NOT NULL REFERENCES tags(id) ON DELETE CASCADE
        )`
        await client.query(query);

        query = `CREATE TABLE IF NOT EXISTS history (
            id SERIAL PRIMARY KEY,
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE,
            video INTEGER NOT NULL REFERENCES videos(id) ON DELETE CASCADE,
            viewed_at TIMESTAMP NOT NULL DEFAULT NOW()
        )`;
        await client.query(query);

        query = `CREATE TABLE IF NOT EXISTS email_verification (
            id SERIAL PRIMARY KEY,
            email VARCHAR(255) NOT NULL,
            token VARCHAR(255) NOT NULL,
            created_at TIMESTAMP NOT NULL DEFAULT NOW(),
            expires_at TIMESTAMP NOT NULL
        )`;
        await client.query(query);

        query = `CREATE TABLE IF NOT EXISTS video_authorized_users (
            id SERIAL PRIMARY KEY,
            video_id INTEGER NOT NULL REFERENCES videos(id) ON DELETE CASCADE,
            user_id INTEGER NOT NULL REFERENCES users(id) ON DELETE CASCADE
        )`;
        await client.query(query);

        // Add GitHub OAuth columns if they don't exist
        try {
            await client.query(`ALTER TABLE users ADD COLUMN IF NOT EXISTS github_id VARCHAR(255) UNIQUE`);
            await client.query(`ALTER TABLE users ADD COLUMN IF NOT EXISTS created_at TIMESTAMP DEFAULT NOW()`);
            await client.query(`ALTER TABLE users ADD COLUMN IF NOT EXISTS updated_at TIMESTAMP DEFAULT NOW()`);
            await client.query(`ALTER TABLE users ALTER COLUMN email DROP NOT NULL`);
            await client.query(`ALTER TABLE users ALTER COLUMN password DROP NOT NULL`);
        } catch (e) {
            console.log("OAuth columns already exist or error adding them:", e.message);
        }

    } catch (e) {
        console.error("Error initializing database:", e);
    } finally {
        client.release();
    }

}