<?php
require 'vendor/autoload.php';

$dotenv = Dotenv\Dotenv::createImmutable(__DIR__);
$dotenv->safeLoad();

try {
    $pdo = new PDO(
        "mysql:host=" . $_ENV['DB_HOST'] . ";dbname=" . $_ENV['DB_NAME'],
        $_ENV['DB_USER'],
        $_ENV['DB_PASS']
    );
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    echo "=== Running Database Migrations: Meta Channel Integration ===\n";

    // 1. Create meta_sessions table
    $createSessionsTableSql = "
        CREATE TABLE IF NOT EXISTS `meta_sessions` (
          `id` INT AUTO_INCREMENT PRIMARY KEY,
          `company_id` INT NOT NULL,
          `channel_type` ENUM('messenger', 'instagram') NOT NULL,
          `page_id` VARCHAR(255) NOT NULL,
          `page_name` VARCHAR(255) NOT NULL,
          `page_access_token` TEXT NOT NULL,
          `status` ENUM('connected', 'disconnected') DEFAULT 'connected',
          `created_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
          `updated_at` TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
          FOREIGN KEY (`company_id`) REFERENCES `companies`(`id`) ON DELETE CASCADE,
          UNIQUE KEY `page_channel_unique` (`page_id`, `channel_type`)
        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
    ";
    $pdo->exec($createSessionsTableSql);
    echo "✅ Table 'meta_sessions' verified/created.\n";

    // 2. Make session_id column in messages_log nullable
    // First check current column definition or just modify it
    $pdo->exec("ALTER TABLE `messages_log` MODIFY COLUMN `session_id` INT NULL");
    echo "✅ Modified 'session_id' in 'messages_log' to be nullable.\n";

    // 3. Add meta_session_id column if not exists
    $result = $pdo->query("SHOW COLUMNS FROM `messages_log` LIKE 'meta_session_id'");
    if ($result->rowCount() === 0) {
        $pdo->exec("ALTER TABLE `messages_log` ADD COLUMN `meta_session_id` INT NULL AFTER `session_id`");
        $pdo->exec("ALTER TABLE `messages_log` ADD CONSTRAINT `fk_msg_meta_session` FOREIGN KEY (`meta_session_id`) REFERENCES `meta_sessions`(`id`) ON DELETE CASCADE");
        echo "✅ Added 'meta_session_id' column and foreign key constraint to 'messages_log'.\n";
    } else {
        echo "ℹ️ Column 'meta_session_id' already exists in 'messages_log'. Skipping.\n";
    }

    echo "Migration completed successfully!\n";
} catch (PDOException $e) {
    echo "❌ Database error: " . $e->getMessage() . "\n";
}