<?php
/**
 * One-time move of stored data from the old short prefix to "forensix_" (D-62).
 *
 * @package ForensixDigital
 */

declare(strict_types=1);

namespace ForensixDigital\Core;

defined( 'ABSPATH' ) || exit;

/**
 * Versions up to 1.0.6 (and Pro up to 0.1.12) stored their settings, tables, meta keys,
 * permissions and schedules under a three-letter prefix. wordpress.org asks for four or more
 * characters, so 1.1.0 uses "forensix_". This class moves existing data to the new names once,
 * so nothing is lost on update. The old prefix appears only here.
 */
final class PrefixMigration {

	/**
	 * Set once the move has run.
	 */
	public const DONE = 'forensix_prefix_moved';

	/**
	 * Held while the move runs, so two requests do not run it at the same time.
	 */
	public const LOCK = 'forensix_prefix_moving';

	/**
	 * Old prefix, without the underscore.
	 */
	private const OLD_PREFIX = 'fxd';

	/**
	 * New prefix, without the underscore.
	 */
	private const NEW_PREFIX = 'forensix';

	/**
	 * Names that belong to the store software on forensix.digital, not to this plugin. They
	 * share the old prefix and must stay as they are.
	 */
	private const KEEP = array( 'backend', 'bk_' );

	/**
	 * Runs the move unless it already ran. Safe to call on every request.
	 */
	public static function maybe_run(): void {
		if ( '1' === get_option( self::DONE ) ) {
			return;
		}
		if ( ! add_option( self::LOCK, (string) time(), '', false ) ) {
			if ( time() - (int) get_option( self::LOCK ) < 5 * MINUTE_IN_SECONDS ) {
				return;
			}
			update_option( self::LOCK, (string) time(), false );
		}
		self::run();
		update_option( self::DONE, '1', true );
		delete_option( self::LOCK );
	}

	/**
	 * The value of a wp-config.php constant, accepting the old name too, or null.
	 *
	 * @param string $suffix Name after the prefix, e.g. ENCRYPTION_KEY.
	 */
	public static function config( string $suffix ): ?string {
		foreach ( array( self::NEW_PREFIX, self::OLD_PREFIX ) as $prefix ) {
			$name = strtoupper( $prefix ) . '_' . $suffix;
			if ( defined( $name ) && is_string( constant( $name ) ) && '' !== constant( $name ) ) {
				return (string) constant( $name );
			}
		}
		return null;
	}

	/**
	 * A stored name with the old prefix changed to the new one, or null when it has none.
	 *
	 * @param string $name Name, e.g. an option name, meta key or table name without $wpdb->prefix.
	 */
	public static function renamed( string $name ): ?string {
		foreach ( self::KEEP as $keep ) {
			if ( str_starts_with( $name, self::OLD_PREFIX . '_' . $keep ) ) {
				return null;
			}
		}
		foreach ( array( '_', '' ) as $lead ) {
			$old = $lead . self::OLD_PREFIX . '_';
			if ( str_starts_with( $name, $old ) ) {
				return $lead . self::NEW_PREFIX . '_' . substr( $name, strlen( $old ) );
			}
		}
		return null;
	}

	/**
	 * Moves everything.
	 */
	private static function run(): void {
		self::options();
		self::tables();
		self::meta();
		self::capabilities();
		self::cron();
		self::action_scheduler();
		wp_cache_flush();
	}

	/**
	 * Settings: renamed. Cached values (transients) are dropped, they are rebuilt on demand.
	 */
	private static function options(): void {
		global $wpdb;
		$old = $wpdb->esc_like( self::OLD_PREFIX . '_' ) . '%';
		foreach ( array( '_transient_', '_transient_timeout_', '_site_transient_', '_site_transient_timeout_' ) as $cache ) {
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- One-time cleanup of our own cached values.
			$wpdb->query( $wpdb->prepare( "DELETE FROM {$wpdb->options} WHERE option_name LIKE %s", $wpdb->esc_like( $cache ) . $old ) );
		}
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- One-time rename of our own options.
		$names = $wpdb->get_col( $wpdb->prepare( "SELECT option_name FROM {$wpdb->options} WHERE option_name LIKE %s", $old ) );
		foreach ( $names as $name ) {
			$new = self::renamed( (string) $name );
			if ( null === $new ) {
				continue;
			}
			// IGNORE keeps an option that already exists under the new name.
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- One-time rename of our own options.
			$wpdb->query( $wpdb->prepare( "UPDATE IGNORE {$wpdb->options} SET option_name = %s WHERE option_name = %s", $new, $name ) );
		}
	}

	/**
	 * Database tables: renamed unless a table with the new name already exists.
	 */
	private static function tables(): void {
		global $wpdb;
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- One-time rename of our own tables.
		$tables = $wpdb->get_col( $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $wpdb->prefix . self::OLD_PREFIX . '_' ) . '%' ) );
		foreach ( $tables as $table ) {
			$new = self::renamed( substr( (string) $table, strlen( $wpdb->prefix ) ) );
			if ( null === $new ) {
				continue;
			}
			$target = $wpdb->prefix . $new;
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- One-time rename of our own tables.
			if ( null !== $wpdb->get_var( $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $target ) ) ) ) {
				continue;
			}
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.DirectDatabaseQuery.SchemaChange, WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Table names cannot be placeholders; both come from SHOW TABLES and our prefix.
			$wpdb->query( 'RENAME TABLE `' . esc_sql( (string) $table ) . '` TO `' . esc_sql( $target ) . '`' );
		}
	}

	/**
	 * Post, user, term and comment meta keys.
	 */
	private static function meta(): void {
		global $wpdb;
		foreach ( array( $wpdb->postmeta, $wpdb->usermeta, $wpdb->termmeta, $wpdb->commentmeta ) as $table ) {
			foreach ( array( '_', '' ) as $lead ) {
				$old = $lead . self::OLD_PREFIX . '_';
				// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Core meta table names; one-time rename of our own keys.
				$wpdb->query( $wpdb->prepare( "UPDATE {$table} SET meta_key = CONCAT( %s, SUBSTRING( meta_key, %d ) ) WHERE meta_key LIKE %s", $lead . self::NEW_PREFIX . '_', strlen( $old ) + 1, $wpdb->esc_like( $old ) . '%' ) );
			}
		}
	}

	/**
	 * Permissions given to roles and to single users.
	 */
	private static function capabilities(): void {
		foreach ( wp_roles()->role_objects as $role ) {
			foreach ( array_keys( $role->capabilities ) as $cap ) {
				$new = self::renamed( (string) $cap );
				if ( null !== $new ) {
					$role->add_cap( $new, (bool) $role->capabilities[ $cap ] );
					$role->remove_cap( (string) $cap );
				}
			}
		}
		global $wpdb;
		$users = get_users(
			array(
				'fields'       => 'ID',
				'meta_key'     => $wpdb->get_blog_prefix() . 'capabilities', // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_key -- One-time lookup.
				'meta_value'   => '"' . self::OLD_PREFIX . '_', // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_value -- One-time lookup.
				'meta_compare' => 'LIKE',
			)
		);
		foreach ( $users as $id ) {
			$user = new \WP_User( (int) $id );
			foreach ( $user->caps as $cap => $granted ) {
				$new = self::renamed( (string) $cap );
				if ( null !== $new ) {
					$user->add_cap( $new, (bool) $granted );
					$user->remove_cap( (string) $cap );
				}
			}
		}
	}

	/**
	 * WP-Cron events keep their time and arguments under the new hook name.
	 */
	private static function cron(): void {
		$crons = _get_cron_array();
		if ( ! is_array( $crons ) || array() === $crons ) {
			return;
		}
		$changed = false;
		foreach ( $crons as $time => $hooks ) {
			if ( ! is_array( $hooks ) ) {
				continue;
			}
			foreach ( $hooks as $hook => $events ) {
				$new = self::renamed( (string) $hook );
				if ( null === $new ) {
					continue;
				}
				$crons[ $time ][ $new ] = array_merge( $crons[ $time ][ $new ] ?? array(), $events );
				unset( $crons[ $time ][ $hook ] );
				$changed = true;
			}
		}
		if ( $changed ) {
			_set_cron_array( $crons );
		}
	}

	/**
	 * Pending Action Scheduler jobs, when that library is used.
	 */
	private static function action_scheduler(): void {
		global $wpdb;
		$table = $wpdb->prefix . 'actionscheduler_actions';
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- One-time check.
		if ( null === $wpdb->get_var( $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $table ) ) ) ) {
			return;
		}
		$old = self::OLD_PREFIX . '_';
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching, WordPress.DB.PreparedSQL.InterpolatedNotPrepared -- Library table; one-time rename of our own pending jobs.
		$wpdb->query( $wpdb->prepare( "UPDATE {$table} SET hook = CONCAT( %s, SUBSTRING( hook, %d ) ) WHERE status = 'pending' AND hook LIKE %s", self::NEW_PREFIX . '_', strlen( $old ) + 1, $wpdb->esc_like( $old ) . '%' ) );
	}
}