<?php

namespace ABeCe\Booking\Infrastructure\Database;

use RuntimeException;

final class Installer {
	public const VERSION_OPTION = 'abece_booking_db_version';
	public const LATEST_VERSION = 13;

	/** @param list<Migration>|null $migrations Ordered, immutable migrations. */
	public function __construct( private readonly \wpdb $wpdb, private readonly ?array $migrations = null ) {}

	public function migrate(): void {
  $wpdb = $this->wpdb;
        if (!\ABeCe\Booking\Support\DatabaseCompatibility::inspect($wpdb)['supported']) {
            throw new RuntimeException(\ABeCe\Booking\Support\DatabaseCompatibility::message($wpdb));
        }
        Tables::validate_prefix($wpdb);
        $layout = DatabaseState::layout($wpdb);
        if (self::LATEST_VERSION === $this->installedVersion()) {
            if (DatabaseState::ready($wpdb)) return;
            throw new RuntimeException('ABECE_BOOKING_INCOMPLETE_SCHEMA13_JOURNAL');
        }
        if ($layout['old'] > 0 || ($layout['state'] !== 'empty' && !get_option(DatabaseState::FRESH))) {
            throw new RuntimeException(__('ABeCe Booking needs a verified database maintenance upgrade before booking operations can resume. Existing data has been retained. Follow the database upgrade instructions or contact your administrator.','abece-booking'));
        }
        if ($this->installedVersion() === 0 && $layout['state'] === 'empty') {
            if (DatabaseState::has_history($wpdb)) throw new RuntimeException('ABECE_BOOKING_PRIOR_INSTALLATION_REQUIRES_RECOVERY');
            update_option(DatabaseState::FRESH, ['database'=>DB_NAME,'prefix'=>$wpdb->prefix], false);
        }
        if (!get_option(DatabaseState::FRESH)) throw new RuntimeException('ABECE_BOOKING_UNIDENTIFIED_PARTIAL_SCHEMA');
		// Serialize installers per database/site; connection close also releases the lock.
		$lock = Tables::lock($wpdb, 'schema');
		if ( '1' !== (string) $wpdb->get_var( $wpdb->prepare( 'SELECT GET_LOCK(%s, 5)', $lock ) ) ) {
			throw new RuntimeException( __( 'ABeCe Booking could not acquire the database migration lock. Please try again.', 'abece-booking' ) );
		}
		try {
			wp_cache_delete( self::VERSION_OPTION, 'options' );
			wp_cache_delete( 'alloptions', 'options' );
			wp_cache_delete( 'notoptions', 'options' );
			$version = $this->installedVersion();
			// Another installer may have completed while this request waited for its lock.
			if ( $version === self::LATEST_VERSION && DatabaseState::ready( $wpdb ) ) {
				return;
			}
			if ( $this->migrations === null && get_option( DatabaseState::FRESH ) ) {
				$this->install_current();
				return;
			}
			foreach ( $this->migrations ?? [ new InitialMigration(), new OperatingScheduleMigration(), new BookingModelMigration(), new PricingMigration(), new CreditPaymentsMigration(), new CancellationMigration(), new ResourceSurfaceMigration(), new ExternalContactsMigration(), new SettingsPaymentsMigration(), new UsageRestrictionsMigration(), new UsageCountingModeMigration(), new PilotOperationsMigration(), new TablePrefixMigration() ] as $migration ) {
				if ( $migration->version() <= $version ) {
					continue;
				}
				if ( $migration->version() !== $version + 1 || $migration->version() > self::LATEST_VERSION ) {
					throw new RuntimeException( __( 'ABeCe Booking encountered an invalid database migration sequence.', 'abece-booking' ) );
				}
				$migration->apply( $wpdb );
				update_option( self::VERSION_OPTION, $migration->version(), false );
				if ( $this->installedVersion() !== $migration->version() ) {
					throw new RuntimeException( __( 'ABeCe Booking could not save the database schema version.', 'abece-booking' ) );
				}
				$version = $migration->version();
			}
			if ( self::LATEST_VERSION !== $version ) {
				throw new RuntimeException( __( 'ABeCe Booking encountered an invalid database migration sequence.', 'abece-booking' ) );
			}
            delete_option(DatabaseState::FRESH);
		} finally {
			$wpdb->get_var( $wpdb->prepare( 'SELECT RELEASE_LOCK(%s)', $lock ) );
		}
	}

	private function installedVersion(): int {
		return DatabaseState::version($this->wpdb);
	}

	/** Create final schema13 definitions directly; never create the legacy namespace. */
	private function install_current(): void {
		$wpdb = $this->wpdb;
		$marker = get_option( DatabaseState::FRESH );
		if ( ! is_array( $marker ) || ( $marker['database'] ?? '' ) !== DB_NAME || ( $marker['prefix'] ?? '' ) !== $wpdb->prefix || DatabaseState::layout( $wpdb )['old'] !== 0 ) {
			throw new RuntimeException( 'ABECE_BOOKING_FRESH_INSTALL_IDENTITY_INVALID' );
		}
		require_once ABSPATH . 'wp-admin/includes/upgrade.php';
		foreach ( Schema::current( $wpdb ) as $table => $sql ) {
			$exists = $wpdb->get_var( $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $table ) ) );
			if ( $wpdb->last_error ) {
				throw new RuntimeException( 'ABECE_BOOKING_FRESH_INSTALL_PREFLIGHT_FAILED' );
			}
			if ( ! $exists ) {
				dbDelta( $sql );
				if ( $wpdb->last_error ) {
					throw new RuntimeException( 'ABECE_BOOKING_FRESH_TABLE_CREATE_FAILED' );
				}
			}
			Schema::verify( $wpdb, $table, $sql );
		}
		( new TablePrefixMigration() )->apply( $wpdb );
		update_option( self::VERSION_OPTION, self::LATEST_VERSION, false );
		if ( $this->installedVersion() !== self::LATEST_VERSION ) {
			throw new RuntimeException( 'ABECE_BOOKING_FRESH_VERSION_COMMIT_FAILED' );
		}
		delete_option( DatabaseState::FRESH );
	}
}