<?php
/**
 * Rollback engine.
 *
 * Reverses supported activities by reading the row's stored context.
 * Every rollback is itself recorded as a new log row referencing the
 * original via the `rollback_of` column.
 *
 * Supported action_types:
 *   - option_updated        → restore old value
 *   - user_role_changed     → restore previous roles
 *   - post_trashed          → untrash the post
 *   - plugin_activated      → deactivate plugin
 *   - plugin_deactivated    → re-activate plugin
 *   - theme_switched        → switch back to the previous theme
 *
 * @package ActivityPilot
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

final class APWPM_Rollback {

	const SUPPORTED = array(
		'option_updated',
		'user_role_changed',
		'post_trashed',
		'plugin_activated',
		'plugin_deactivated',
		'theme_switched',
	);

	/**
	 * Returns true when a row can be rolled back.
	 */
	public static function can_rollback( array $row ) {
		if ( false === APWPM_Compat::filter( 'apwpm_can_rollback', 'ap_can_rollback', true, $row ) ) {
			return false;
		}
		if ( ! in_array( $row['action_type'], self::SUPPORTED, true ) ) {
			return false;
		}
		if ( ! empty( $row['rolled_back'] ) ) {
			return false;
		}
		return true;
	}

	/**
	 * Execute the rollback for a given log row id.
	 *
	 * @param int $log_id
	 * @return array { success: bool, message: string }
	 */
	public static function execute( $log_id ) {
		$row = APWPM_DB::get_log_by_id( $log_id );

		if ( ! $row ) {
			return array( 'success' => false, 'message' => __( 'Log entry not found.', 'activitypilot' ) );
		}
		if ( ! self::can_rollback( $row ) ) {
			return array( 'success' => false, 'message' => __( 'This action is not rollback-eligible.', 'activitypilot' ) );
		}

		$ctx = ! empty( $row['context'] ) ? json_decode( $row['context'], true ) : array();
		if ( ! is_array( $ctx ) ) {
			$ctx = array();
		}

		try {
			switch ( $row['action_type'] ) {
				case 'option_updated':
					$result = self::rollback_option( $row, $ctx );
					break;
				case 'user_role_changed':
					$result = self::rollback_user_role( $row, $ctx );
					break;
				case 'post_trashed':
					$result = self::rollback_post_trash( $row );
					break;
				case 'plugin_activated':
					$result = self::rollback_plugin_activate( $row );
					break;
				case 'plugin_deactivated':
					$result = self::rollback_plugin_deactivate( $row );
					break;
				case 'theme_switched':
					$result = self::rollback_theme_switch( $row, $ctx );
					break;
				default:
					$result = array( 'success' => false, 'message' => __( 'Unsupported action.', 'activitypilot' ) );
			}
		} catch ( Throwable $e ) {
			$result = array( 'success' => false, 'message' => $e->getMessage() );
		}

		if ( $result['success'] ) {
			APWPM_DB::update_log_fields( (int) $row['id'], array( 'rolled_back' => 1 ), array( '%d' ) );

			$new_id = APWPM_Logger::log(
				array(
					'action_type'  => 'rollback_performed',
					'object_type'  => $row['object_type'],
					'object_id'    => (int) $row['object_id'],
					'object_title' => (string) $row['object_title'],
					'description'  => sprintf(
						/* translators: 1: original action_type, 2: object title */
						__( 'Rolled back "%1$s" on %2$s.', 'activitypilot' ),
						$row['action_type'],
						$row['object_title']
					),
					'severity'     => 'warning',
					'context'      => array(
						'original_log_id'     => (int) $row['id'],
						'original_action'     => $row['action_type'],
						'rollback_outcome'    => $result['message'],
					),
				)
			);

			if ( $new_id ) {
				APWPM_DB::update_log_fields( (int) $new_id, array( 'rollback_of' => (int) $row['id'] ), array( '%d' ) );
			}
		}

		return $result;
	}

	/* ---------------------------------------------------------------- */

	protected static function rollback_option( $row, $ctx ) {
		if ( empty( $row['object_title'] ) ) {
			return array( 'success' => false, 'message' => __( 'Missing option name.', 'activitypilot' ) );
		}
		if ( ! array_key_exists( 'old', $ctx ) ) {
			return array( 'success' => false, 'message' => __( 'Previous option value not captured.', 'activitypilot' ) );
		}
		if ( '(complex)' === $ctx['old'] ) {
			return array( 'success' => false, 'message' => __( 'Previous value was too complex to capture safely.', 'activitypilot' ) );
		}
		update_option( $row['object_title'], $ctx['old'] );
		return array( 'success' => true, 'message' => __( 'Option value restored.', 'activitypilot' ) );
	}

	protected static function rollback_user_role( $row, $ctx ) {
		$uid = (int) $row['object_id'];
		if ( ! $uid ) {
			return array( 'success' => false, 'message' => __( 'Missing user ID.', 'activitypilot' ) );
		}
		$user = get_user_by( 'id', $uid );
		if ( ! $user ) {
			return array( 'success' => false, 'message' => __( 'User no longer exists.', 'activitypilot' ) );
		}
		$old_roles = isset( $ctx['old_roles'] ) ? (array) $ctx['old_roles'] : array();
		if ( empty( $old_roles ) ) {
			return array( 'success' => false, 'message' => __( 'No previous role recorded.', 'activitypilot' ) );
		}
		foreach ( (array) $user->roles as $r ) {
			$user->remove_role( $r );
		}
		foreach ( $old_roles as $r ) {
			if ( is_string( $r ) && $r ) {
				$user->add_role( sanitize_key( $r ) );
			}
		}
		return array( 'success' => true, 'message' => __( 'User roles restored.', 'activitypilot' ) );
	}

	protected static function rollback_post_trash( $row ) {
		$pid = (int) $row['object_id'];
		if ( ! $pid ) {
			return array( 'success' => false, 'message' => __( 'Missing post ID.', 'activitypilot' ) );
		}
		$ok = wp_untrash_post( $pid );
		if ( ! $ok ) {
			return array( 'success' => false, 'message' => __( 'Untrash failed.', 'activitypilot' ) );
		}
		return array( 'success' => true, 'message' => __( 'Post restored from trash.', 'activitypilot' ) );
	}

	protected static function rollback_plugin_activate( $row ) {
		if ( empty( $row['object_title'] ) ) {
			return array( 'success' => false, 'message' => __( 'Missing plugin path.', 'activitypilot' ) );
		}
		if ( ! function_exists( 'deactivate_plugins' ) ) {
			require_once ABSPATH . 'wp-admin/includes/plugin.php';
		}
		deactivate_plugins( $row['object_title'] );
		return array( 'success' => true, 'message' => __( 'Plugin deactivated.', 'activitypilot' ) );
	}

	protected static function rollback_plugin_deactivate( $row ) {
		if ( empty( $row['object_title'] ) ) {
			return array( 'success' => false, 'message' => __( 'Missing plugin path.', 'activitypilot' ) );
		}
		if ( ! function_exists( 'activate_plugin' ) ) {
			require_once ABSPATH . 'wp-admin/includes/plugin.php';
		}
		$result = activate_plugin( $row['object_title'] );
		if ( is_wp_error( $result ) ) {
			return array( 'success' => false, 'message' => $result->get_error_message() );
		}
		return array( 'success' => true, 'message' => __( 'Plugin reactivated.', 'activitypilot' ) );
	}

	protected static function rollback_theme_switch( $row, $ctx ) {
		if ( empty( $ctx['old_stylesheet'] ) ) {
			return array( 'success' => false, 'message' => __( 'Previous theme not recorded.', 'activitypilot' ) );
		}
		$old   = (string) $ctx['old_stylesheet'];
		$theme = wp_get_theme( $old );
		if ( ! $theme->exists() ) {
			return array( 'success' => false, 'message' => __( 'Previous theme is no longer installed.', 'activitypilot' ) );
		}
		switch_theme( $old );
		return array( 'success' => true, 'message' => __( 'Theme reverted.', 'activitypilot' ) );
	}
}