import mysql from 'mysql2/promise';

const pool = mysql.createPool({
    host: process.env.DB_HOST || 'localhost',
    port: parseInt(process.env.DB_PORT || '3306'),
    user: process.env.DB_USER || 'root',
    password: process.env.DB_PASSWORD || 'scrumpass',
    database: process.env.DB_NAME || 'scrum_manager',
    waitForConnections: true,
    connectionLimit: 10,
    queueLimit: 0,
});

export async function initDB() {
    const conn = await pool.getConnection();
    try {
        await conn.query(`
      CREATE TABLE IF NOT EXISTS users (
        id VARCHAR(36) PRIMARY KEY,
        name VARCHAR(255) NOT NULL,
        role VARCHAR(50) NOT NULL DEFAULT 'employee',
        email VARCHAR(255) NOT NULL UNIQUE,
        password_hash VARCHAR(255) NOT NULL,
        color VARCHAR(20) DEFAULT '#818cf8',
        avatar VARCHAR(10) DEFAULT '',
        dept VARCHAR(100) DEFAULT ''
      )
    `);

        await conn.query(`
      CREATE TABLE IF NOT EXISTS tasks (
        id VARCHAR(36) PRIMARY KEY,
        title VARCHAR(500) NOT NULL,
        description TEXT,
        status ENUM('todo','inprogress','review','done') NOT NULL DEFAULT 'todo',
        priority ENUM('critical','high','medium','low') NOT NULL DEFAULT 'medium',
        assignee_id VARCHAR(36),
        reporter_id VARCHAR(36),
        due_date DATE,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
        FOREIGN KEY (assignee_id) REFERENCES users(id) ON DELETE SET NULL,
        FOREIGN KEY (reporter_id) REFERENCES users(id) ON DELETE SET NULL
      )
    `);

        await conn.query(`
      CREATE TABLE IF NOT EXISTS subtasks (
        id VARCHAR(36) PRIMARY KEY,
        task_id VARCHAR(36) NOT NULL,
        title VARCHAR(500) NOT NULL,
        done BOOLEAN DEFAULT FALSE,
        FOREIGN KEY (task_id) REFERENCES tasks(id) ON DELETE CASCADE
      )
    `);

        await conn.query(`
      CREATE TABLE IF NOT EXISTS comments (
        id VARCHAR(36) PRIMARY KEY,
        task_id VARCHAR(36) NOT NULL,
        user_id VARCHAR(36),
        text TEXT NOT NULL,
        timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
        FOREIGN KEY (task_id) REFERENCES tasks(id) ON DELETE CASCADE,
        FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE SET NULL
      )
    `);

        await conn.query(`
      CREATE TABLE IF NOT EXISTS activities (
        id VARCHAR(36) PRIMARY KEY,
        task_id VARCHAR(36) NOT NULL,
        text TEXT NOT NULL,
        timestamp TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
        FOREIGN KEY (task_id) REFERENCES tasks(id) ON DELETE CASCADE
      )
    `);

        await conn.query(`
      CREATE TABLE IF NOT EXISTS task_tags (
        id INT AUTO_INCREMENT PRIMARY KEY,
        task_id VARCHAR(36) NOT NULL,
        tag VARCHAR(100) NOT NULL,
        FOREIGN KEY (task_id) REFERENCES tasks(id) ON DELETE CASCADE,
        UNIQUE KEY unique_task_tag (task_id, tag)
      )
    `);

        console.log('✅ Database tables initialized');
    } finally {
        conn.release();
    }
}

export default pool;