<?php

namespace Commands;

use Interfaces\CommandInterface;
use Libs\Database;
use Libs\Migration as LibsMigration;
use Override;
use PDO;

class Migration implements CommandInterface
{
    public static function describe(): string
    {
        return 'Migraciones de base de datos (create, migrate, rollback, fresh, clear)';
    }

    private const MIGRATIONS_PATH = ROOT_DIR . '/migrations/';
    private string $migratonsDatabaseFile;
    private PDO $db;

    public function __construct(public bool $verbose = true)
    {
        $key = md5(DB_TYPE . '/' . DB_HOST . '/' . DB_NAME . '/' . DB_USER);
        $this->migratonsDatabaseFile = "migrations-{$key}.sqlite";
        $this->db = Database::getInstance(
            type: 'sqlite',
            name: static::MIGRATIONS_PATH . $this->migratonsDatabaseFile,
        );
    }

    #[Override]
    public function run(): void
    {
        $args = func_get_args();

        $this->ensureDatabaseExists();

        $command = $args[0] ?? '';

        switch ($command) {
            case 'migrate':
                $this->migrate();
                break;
            case 'rollback':
                $this->rollback((int)($args[1] ?? 0));
                break;
            case 'create':
                $this->create((string)($args[1] ?? 'migration'));
                break;
            case 'fresh':
                $this->fresh();
                break;
            case 'clear':
                $this->dropAllTables();
                break;
            default:
                $this->log('Invalid migration command.');
                break;
        }
    }

    /**
     * Ensures that the migrations table exists in the database.
     *
     * @return void
     */
    public function ensureDatabaseExists(): void
    {
        $this->db->query(
            "CREATE TABLE IF NOT EXISTS migrations (id INTEGER PRIMARY KEY, migration TEXT, batch INTEGER)"
        );
    }

    /**
     * Runs all pending migrations.
     *
     * @return void
     */
    public function migrate(): void
    {
        $files = glob(rtrim(static::MIGRATIONS_PATH, '/') . '/*.php');
        $quantity = 1;
        foreach ($files as $file) {
            // Verificamos si la migración ya ha sigo realizada
            $filename = basename($file);
            $prepared = $this->db->prepare("SELECT id FROM migrations WHERE migration = ?");
            $prepared->execute([$filename]);

            if ((bool) $prepared->fetch()) {
                continue;
            }
            // Obtener la migración
            $migration = require $file;

            if ($migration instanceof LibsMigration) {
                if ($this->verbose) {
                    $this->log('Running migration: %s', $filename);
                }
                $migration->up();
                // agregar la migracion a la base de datos
                $stmt = $this->db->prepare("INSERT INTO migrations (migration, batch) VALUES (?, ?)");
                $stmt->execute([$filename, $quantity]);
                $quantity++;
            }
        }
        $this->log("Migrations completed successfully.");
    }

    /**
     * Rolls back a specified number of migrations or by default rollback lates batch of it.
     *
     * @param int $steps The number of migrations to rollback.
     *
     * @return void
     */
    public function rollback(int $steps = 0): void
    {
        if ($steps <= 0) {
            $steps = $this->db->query(
                "SELECT batch FROM migrations ORDER BY id DESC LIMIT 1"
            )->fetchColumn();
            if ($steps === false) {
                $this->log("No migrations to rollback.");
                return;
            }
        }

        $stmt = $this->db->query("SELECT migration FROM migrations ORDER BY id DESC LIMIT $steps");
        $migrations = $stmt->fetchAll(PDO::FETCH_COLUMN);
        foreach ($migrations as $filename) {
            $file = static::MIGRATIONS_PATH . $filename;
            if (file_exists($file)) {
                $migration = require $file;
                if ($migration instanceof LibsMigration) {
                    $this->log('Rolling back migration: %s', $filename);
                    $migration->down();
                }
            }
            $this->db->prepare("DELETE FROM migrations WHERE migration = ?")->execute([$filename]);
        }
        $this->log('Rollback completed successfully.');
    }

    /**
     * Creates a new migration file.
     *
     * @param string $name
     *
     * @return void
     */
    public function create(string $name = 'migration'): void
    {
        $filename = date('Y_m_d_His') . '_' . $name . '.php';
        $filepath = static::MIGRATIONS_PATH . $filename;

        $template = <<<'TEMPLATE'
<?php

use Libs\Migration;

return new class () extends Migration {
    #[Override]
    public function up(): void
    {
    }

    #[Override]
    public function down(): void
    {
    }
};
TEMPLATE;

        file_put_contents($filepath, $template);
        $this->log('%s migration created.', $filename);
    }

    /**
     * Refreshes the database by deleting the database and running all migrations.
     *
     * @return void
     */
    public function fresh(): void
    {
        $this->dropAllTables();
        $this->migrate();
        $this->log("Database refreshed successfully.");
    }

    /**
     * Drops all tables from the main database and clears the migrations control table.
     *
     * @return void
     * @throws \Exception If the database driver is not supported.
     */
    private function dropAllTables(): void
    {
        if (DB_TYPE == 'sqlite') {
            $mainDatabase = Database::getInstance(
                type: DB_TYPE,
                name: DB_NAME
            );
        } else {
            $mainDatabase = Database::getInstance(
                DB_TYPE,
                DB_HOST,
                DB_NAME,
                DB_USER,
                DB_PASS
            );
        }
        $driver = $mainDatabase->getAttribute(PDO::ATTR_DRIVER_NAME);

        // Query to get all tables based on the driver
        $query = match ($driver) {
            'mysql' => "SHOW TABLES",
            'pgsql' => "SELECT tablename FROM pg_catalog.pg_tables WHERE schemaname != 'pg_catalog' AND schemaname != 'information_schema'",
            'sqlite' => "SELECT name FROM sqlite_master WHERE type='table' AND name NOT LIKE 'sqlite_%'",
            default => throw new \Exception("Driver $driver not supported for fresh command"),
        };

        $stmt = $mainDatabase->query($query);
        $tables = $stmt->fetchAll(PDO::FETCH_COLUMN);

        foreach ($tables as $table) {
            // Disable foreign key checks to avoid constraint errors
            if ($driver === 'mysql') {
                $mainDatabase->exec("SET FOREIGN_KEY_CHECKS = 0");
            }
            if ($driver === 'pgsql') {
                $mainDatabase->exec("SET session_replication_role = 'replica'");
            }

            $quotedTable = match ($driver) {
                'mysql' => "`$table`",
                'pgsql', 'sqlite' => "\"$table\"",
                default => $table,
            };

            $cascade = $driver === 'sqlite' ? '' : ' CASCADE';

            $mainDatabase->exec("DROP TABLE IF EXISTS $quotedTable$cascade");
        }

        if ($driver === 'mysql') {
            $mainDatabase->exec("SET FOREIGN_KEY_CHECKS = 1");
        }
        if ($driver === 'pgsql') {
            $mainDatabase->exec("SET session_replication_role = 'origin'");
        }

        // Clear the migration control table in the SQLite DB
        $this->db->exec("DELETE FROM migrations");
        $this->log("Database schema cleared. Ready for new migrations.");
    }

    private function log(string $msg, mixed ...$args): void
    {
        if ($this->verbose) {
            printf("$msg\n", ...$args);
        }
    }
}