<?php
/**
 * Complete data removal on uninstall.
 *
 * @package Unbreak
 */

namespace Unbreak\Install;

defined( 'ABSPATH' ) || exit;

/**
 * Removes every table, option, transient and scheduled action the plugin created.
 */
final class Uninstaller {

	/**
	 * Action Scheduler group used by this plugin. Duplicated from Jobs::GROUP so uninstall has no other dependency.
	 */
	private const AS_GROUP = 'unbreak';

	/**
	 * Uninstall for the whole install (all sites on multisite).
	 */
	public static function run(): void {
		if ( is_multisite() ) {
			$site_ids = get_sites(
				array(
					'fields' => 'ids',
					'number' => 0,
				)
			);
			foreach ( $site_ids as $site_id ) {
				switch_to_blog( (int) $site_id );
				self::cleanup_site();
				restore_current_blog();
			}
			self::cleanup_network();
		} else {
			self::cleanup_site();
		}
		self::cleanup_users();
	}

	/**
	 * Remove everything for the current site.
	 */
	public static function cleanup_site(): void {
		Schema::drop_all();
		self::delete_options();
		self::cleanup_action_scheduler();
		wp_cache_delete( 'alloptions', 'options' );
	}

	/**
	 * Delete every option and transient whose name starts with unbreak_.
	 */
	private static function delete_options(): void {
		global $wpdb;
		$patterns = array(
			'unbreak\_%',
			'\_transient\_unbreak\_%',
			'\_transient\_timeout\_unbreak\_%',
			'\_site\_transient\_unbreak\_%',
			'\_site\_transient\_timeout\_unbreak\_%',
		);
		foreach ( $patterns as $pattern ) {
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- One-off uninstall lookup.
			$names = $wpdb->get_col( $wpdb->prepare( "SELECT option_name FROM {$wpdb->options} WHERE option_name LIKE %s", $pattern ) );
			foreach ( $names as $name ) {
				delete_option( $name );
			}
		}
	}

	/**
	 * Remove network-wide (sitemeta) options on multisite.
	 */
	private static function cleanup_network(): void {
		global $wpdb;
		$patterns = array( 'unbreak\_%', '\_site\_transient\_unbreak\_%', '\_site\_transient\_timeout\_unbreak\_%' );
		foreach ( $patterns as $pattern ) {
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- One-off uninstall lookup.
			$names = $wpdb->get_col( $wpdb->prepare( "SELECT meta_key FROM {$wpdb->sitemeta} WHERE meta_key LIKE %s", $pattern ) );
			foreach ( $names as $name ) {
				delete_site_option( $name );
			}
		}
	}

	/**
	 * Remove user meta written by the plugin (per-user UI preferences).
	 */
	private static function cleanup_users(): void {
		global $wpdb;
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching,WordPress.DB.SlowDBQuery.slow_db_query_meta_key -- One-off uninstall cleanup.
		$wpdb->query( $wpdb->prepare( "DELETE FROM {$wpdb->usermeta} WHERE meta_key LIKE %s", 'unbreak\_%' ) );
	}

	/**
	 * Remove our Action Scheduler actions and logs. If that leaves the shared Action Scheduler tables
	 * completely empty, drop them too (Action Scheduler recreates them when another plugin needs them).
	 */
	private static function cleanup_action_scheduler(): void {
		global $wpdb;
		$actions = $wpdb->prefix . 'actionscheduler_actions';
		$groups  = $wpdb->prefix . 'actionscheduler_groups';
		$logs    = $wpdb->prefix . 'actionscheduler_logs';
		$claims  = $wpdb->prefix . 'actionscheduler_claims';

		if ( ! self::table_exists( $actions ) || ! self::table_exists( $groups ) ) {
			return;
		}

		// phpcs:disable WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching,WordPress.DB.DirectDatabaseQuery.SchemaChange -- Uninstall cleanup of known tables; everything is prepared.
		$group_id = (int) $wpdb->get_var( $wpdb->prepare( 'SELECT group_id FROM %i WHERE slug = %s', $groups, self::AS_GROUP ) );
		if ( $group_id > 0 ) {
			if ( self::table_exists( $logs ) ) {
				$wpdb->query( $wpdb->prepare( 'DELETE l FROM %i l INNER JOIN %i a ON l.action_id = a.action_id WHERE a.group_id = %d', $logs, $actions, $group_id ) );
			}
			$wpdb->query( $wpdb->prepare( 'DELETE FROM %i WHERE group_id = %d', $actions, $group_id ) );
			$wpdb->query( $wpdb->prepare( 'DELETE FROM %i WHERE group_id = %d', $groups, $group_id ) );
		}

		$remaining_actions = (int) $wpdb->get_var( $wpdb->prepare( 'SELECT COUNT(*) FROM %i', $actions ) );
		$remaining_groups  = (int) $wpdb->get_var( $wpdb->prepare( 'SELECT COUNT(*) FROM %i', $groups ) );
		if ( 0 === $remaining_actions && 0 === $remaining_groups ) {
			foreach ( array( $actions, $groups, $logs, $claims ) as $table ) {
				$wpdb->query( $wpdb->prepare( 'DROP TABLE IF EXISTS %i', $table ) );
			}
			$as_options = array(
				'schema-ActionScheduler_StoreSchema',
				'schema-ActionScheduler_LoggerSchema',
				'action_scheduler_hybrid_store_demarkation',
				'action_scheduler_migration_status',
				'action_scheduler_lock_async-request-runner',
				'as_has_wp_comment_logs',
			);
			foreach ( $as_options as $option ) {
				delete_option( $option );
			}
		}
		// phpcs:enable
	}

	/**
	 * Whether a table exists.
	 *
	 * @param string $table Full table name.
	 */
	private static function table_exists( string $table ): bool {
		global $wpdb;
		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery,WordPress.DB.DirectDatabaseQuery.NoCaching -- Schema introspection.
		return $table === $wpdb->get_var( $wpdb->prepare( 'SHOW TABLES LIKE %s', $wpdb->esc_like( $table ) ) );
	}
}