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

// Configuration from .env or defaults
const dbConfig = {
  host: process.env.DB_HOST || 'localhost',
  user: process.env.DB_USER || 'root',
  password: process.env.DB_PASS || '',
  database: process.env.DB_NAME || 'condominio',
  port: process.env.DB_PORT || 3306,
  waitForConnections: true,
  connectionLimit: 10,
  queueLimit: 0
};

const pool = mysql.createPool(dbConfig);

const initDb = async () => {
  try {
    const connection = await pool.getConnection();
    console.log('Database connected successfully.');

    // 1. Settings Table
    await connection.query(`
      CREATE TABLE IF NOT EXISTS settings (
        id INT PRIMARY KEY DEFAULT 1,
        condo_name VARCHAR(255) DEFAULT 'Il Mio Condominio',
        default_monthly_quota DECIMAL(10, 2) DEFAULT 100.00,
        current_year INT
      )
    `);

    const [rows] = await connection.query('SELECT * FROM settings WHERE id = 1');
    if (rows.length === 0) {
      const currentYear = new Date().getFullYear();
      await connection.query(
        'INSERT INTO settings (id, condo_name, default_monthly_quota, current_year) VALUES (1, ?, ?, ?)',
        ['Condominio Demo', 100.00, currentYear]
      );
    }

    // 2. Families Table
    await connection.query(`
      CREATE TABLE IF NOT EXISTS families (
        id VARCHAR(36) PRIMARY KEY,
        name VARCHAR(255) NOT NULL,
        unit_number VARCHAR(50),
        contact_email VARCHAR(255),
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
      )
    `);

    // 3. Payments Table
    await connection.query(`
      CREATE TABLE IF NOT EXISTS payments (
        id VARCHAR(36) PRIMARY KEY,
        family_id VARCHAR(36) NOT NULL,
        amount DECIMAL(10, 2) NOT NULL,
        date_paid DATETIME NOT NULL,
        for_month INT NOT NULL,
        for_year INT NOT NULL,
        notes TEXT,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
        FOREIGN KEY (family_id) REFERENCES families(id) ON DELETE CASCADE
      )
    `);

    // 4. Users Table
    await connection.query(`
      CREATE TABLE IF NOT EXISTS users (
        id VARCHAR(36) PRIMARY KEY,
        email VARCHAR(255) UNIQUE NOT NULL,
        password_hash VARCHAR(255) NOT NULL,
        name VARCHAR(255),
        role VARCHAR(20) DEFAULT 'user',
        phone VARCHAR(20),
        family_id VARCHAR(36) NULL,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
        FOREIGN KEY (family_id) REFERENCES families(id) ON DELETE SET NULL
      )
    `);

    // --- MIGRATION: CHECK FOR PHONE COLUMN ---
    // This ensures existing databases get the new column without dropping the table
    try {
      const [columns] = await connection.query("SHOW COLUMNS FROM users LIKE 'phone'");
      if (columns.length === 0) {
        console.log('Adding missing "phone" column to users table...');
        await connection.query("ALTER TABLE users ADD COLUMN phone VARCHAR(20)");
      }
    } catch (migError) {
      console.warn("Migration check failed:", migError.message);
    }

    // Seed Admin User
    const [admins] = await connection.query('SELECT * FROM users WHERE email = ?', ['fcarra79@gmail.com']);
    if (admins.length === 0) {
      const hashedPassword = await bcrypt.hash('Mr10921.', 10);
      const { v4: uuidv4 } = require('uuid');
      await connection.query(
        'INSERT INTO users (id, email, password_hash, name, role) VALUES (?, ?, ?, ?, ?)',
        [uuidv4(), 'fcarra79@gmail.com', hashedPassword, 'Amministratore', 'admin']
      );
      console.log('Default Admin user created.');
    }

    console.log('Database tables initialized.');
    connection.release();
  } catch (error) {
    console.error('Database initialization failed:', error);
    process.exit(1);
  }
};

module.exports = { pool, initDb };