<?php
require_once 'db/config.php';

try {
    $pdo = db();
    $pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

    // 1. Create migrations table if it doesn't exist
    $pdo->exec("CREATE TABLE IF NOT EXISTS migrations (
        id INT AUTO_INCREMENT PRIMARY KEY,
        migration_file VARCHAR(255) NOT NULL,
        created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
        UNIQUE KEY (migration_file)
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;");

    // 2. Pre-populate with migrations that are known to have run already
    $known_migrations = [
        '001_create_assets_table.sql',
        '002_create_users_table.sql',
        '003_create_permissions_table.sql',
        '004_create_categories_table.sql',
        '005_add_category_id_to_assets.sql'
    ];

    $stmt = $pdo->prepare("INSERT IGNORE INTO migrations (migration_file) VALUES (?)");
    foreach ($known_migrations as $migration) {
        $stmt->execute([$migration]);
    }

    // 3. Get all migrations that have already been run
    $ran_migrations_stmt = $pdo->query("SELECT migration_file FROM migrations");
    $ran_migrations = $ran_migrations_stmt->fetchAll(PDO::FETCH_COLUMN);

    // 4. Get all available migration files
    $migration_files = glob('db/migrations/*.sql');
    sort($migration_files);

    // 5. Determine which migrations to run
    $migrations_to_run = [];
    foreach ($migration_files as $file) {
        if (!in_array(basename($file), $ran_migrations)) {
            $migrations_to_run[] = $file;
        }
    }

    if (empty($migrations_to_run)) {
        echo "Database is already up to date.\n";
    } else {
        // 6. Run the new migrations
        foreach ($migrations_to_run as $file) {
            try {
                $sql = file_get_contents($file);
                if (empty(trim($sql))) {
                    echo "Skipping empty migration file: $file\n";
                    $stmt = $pdo->prepare("INSERT INTO migrations (migration_file) VALUES (?)");
                    $stmt->execute([basename($file)]);
                    continue;
                }
                
                $pdo->exec($sql);

                $stmt = $pdo->prepare("INSERT INTO migrations (migration_file) VALUES (?)");
                $stmt->execute([basename($file)]);

                echo "Successfully ran migration: " . basename($file) . "\n";

            } catch (PDOException $e) {
                echo "Error running migration " . basename($file) . ": " . $e->getMessage() . "\n";
                exit(1); 
            }
        }
        echo "All new migrations ran successfully.\n";
    }

} catch (PDOException $e) {
    die("Database error: " . $e->getMessage());
}
?>