const mysql = require('mysql2/promise');
require('dotenv').config();

const pool = mysql.createPool({
    host: process.env.DB_HOST,
    user: process.env.DB_USER,
    password: process.env.DB_PASSWORD,
    database: process.env.DB_NAME,
});

/**
 * Initialize the database and create necessary tables
 * 
 */
async function initDB() {
    try {
        const connection = await pool.getConnection();

        // Create users table if it doesn't exist
        await connection.query(`
            CREATE TABLE IF NOT EXISTS users (
                id INT AUTO_INCREMENT PRIMARY KEY NOT NULL,
                username VARCHAR(50) NOT NULL UNIQUE,
                password VARCHAR(255) NOT NULL,
                role VARCHAR(20) DEFAULT 'user',
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
            );
        `);

        // table fournisseurs
        await connection.query(`
            CREATE TABLE IF NOT EXISTS fournisseurs (
                id BIGINT AUTO_INCREMENT PRIMARY KEY NOT NULL,
                name VARCHAR(255) NOT NULL,
                category VARCHAR(50) NOT NULL,
                contact_person VARCHAR(255) DEFAULT NULL,
                phone VARCHAR(20) DEFAULT NULL,
                email VARCHAR(255) DEFAULT NULL,
                status VARCHAR(20) DEFAULT 'active',
                last_order_date DATE DEFAULT NULL,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
            );
        `);

        // Create emplacements table if it doesn't exist
        await connection.query(`
            CREATE TABLE IF NOT EXISTS emplacements (
                id BIGINT AUTO_INCREMENT PRIMARY KEY NOT NULL,
                name VARCHAR(255) NOT NULL,
                type VARCHAR(50) NOT NULL,
                temperature DECIMAL(5, 2) DEFAULT NULL,
                capacity INT DEFAULT NULL,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
            );
        `);

        // table compartiments 
        await connection.query(`
            CREATE TABLE IF NOT EXISTS compartiments (
                id BIGINT AUTO_INCREMENT PRIMARY KEY NOT NULL,
                name VARCHAR(255) NOT NULL,
                capacity INT DEFAULT NULL,
                uniter VARCHAR(50) NOT NULL DEFAULT 'kg',
                id_emplacement BIGINT NOT NULL,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                FOREIGN KEY (id_emplacement) REFERENCES emplacements(id) ON DELETE CASCADE
            );
        `);

        // table stock
        await connection.query(`
            CREATE TABLE IF NOT EXISTS stocks (
                id BIGINT AUTO_INCREMENT PRIMARY KEY NOT NULL,
                articles VARCHAR(255) NOT NULL,
                quantity INT NOT NULL DEFAULT 0,
                uniter VARCHAR(50) NOT NULL DEFAULT 'kg',
                price_unit DECIMAL(10, 2) NOT NULL DEFAULT 0.00,
                id_emplacement BIGINT NOT NULL,
                id_compartiment BIGINT NOT NULL,
                fournisseur_id BIGINT DEFAULT NULL,
                created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
                FOREIGN KEY (id_emplacement) REFERENCES emplacements(id) ON DELETE CASCADE,
                FOREIGN KEY (fournisseur_id) REFERENCES fournisseurs(id) ON DELETE SET NULL,
                FOREIGN KEY (id_compartiment) REFERENCES compartiments(id) ON DELETE CASCADE
            );
        `);

        // ajoute une autre table si necessaire

        // add a default admin user if none exists
        const [rows] = await connection.query(`SELECT COUNT(*) as count FROM users`);
        if (rows[0].count === 0) {
            const bcrypt = require('bcryptjs');
            const hashedPassword = await bcrypt.hash('admin123', 10);

            await connection.query(
                'INSERT INTO users (username, password, role) VALUES (?, ?, ?)',
                ['admin', hashedPassword, 'admin']
            );

            console.log('✅ Default admin user created: admin / admin123');
        }

        connection.release();
        console.log('✅ Database initialized');
    } catch (err) {
        console.error('❌ Failed to initialize database:', err.message);
    }
}

module.exports = {
  pool,
  initDB,
};