<?php
/**
 * Uninstall routine.
 *
 * @package FormPilot
 * @since   1.0.0
 */

declare( strict_types = 1 );

namespace FormPilot\Core;

use FormPilot\Database\Installer;
use FormPilot\Logging\LogStore;
use FormPilot\Notifications\CronQueue;
use FormPilot\Services\SavedFilters;
use FormPilot\Settings\Settings;
use FormPilot\Uploads\UploadManager;

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

/**
 * Removes the plugin footprint when it is deleted.
 *
 * Data is only destroyed when the site owner opted in through the
 * `formpilot_remove_data_on_uninstall` option, mirroring WordPress conventions.
 *
 * @since 1.0.0
 */
final class Uninstaller {

	/**
	 * Option controlling whether plugin data is deleted on uninstall.
	 */
	public const REMOVE_DATA_OPTION = 'formpilot_remove_data_on_uninstall';

	/**
	 * Handles plugin deletion.
	 */
	public static function uninstall(): void {
		/*
		 * No capability check: WordPress only fires this from a path that has
		 * already authorised the caller, and under WP-CLI or a deploy script there
		 * is no current user at all - the check made `wp plugin uninstall` silently do
		 * nothing.
		 */

		if ( is_multisite() ) {
			foreach ( get_sites(
				array(
					'fields' => 'ids',
					'number' => 0,
				)
			) as $site_id ) {
				switch_to_blog( (int) $site_id );
				self::uninstall_site();
				restore_current_blog();
			}

			return;
		}

		self::uninstall_site();
	}

	/**
	 * Removes the log files and the directory holding them.
	 */
	private static function delete_logs(): void {
		( new LogStore() )->clear();

		$directory = LogStore::directory();

		if ( '' === $directory || ! is_dir( $directory ) ) {
			return;
		}

		if ( ! function_exists( 'WP_Filesystem' ) ) {
			require_once ABSPATH . 'wp-admin/includes/file.php';
		}

		WP_Filesystem();

		global $wp_filesystem;

		if ( ! $wp_filesystem instanceof \WP_Filesystem_Base ) {
			return;
		}

		/*
		 * By name, and never recursively: `formpilot_log_directory` can point the logs
		 * anywhere, and a recursive delete would take everything else in that
		 * directory with them. The list missed the web.config LogStore also
		 * writes, so the directory was never empty, the rmdir() failed with a
		 * warning, and an uninstall told to remove everything left it behind.
		 */
		foreach ( array( '.htaccess', 'index.php', 'web.config' ) as $guard ) {
			if ( $wp_filesystem->is_file( $directory . $guard ) ) {
				$wp_filesystem->delete( $directory . $guard );
			}
		}

		// Only succeeds when empty, so a shared directory survives.
		$wp_filesystem->rmdir( $directory, false );
	}

	/**
	 * Performs the uninstall tasks for the current site.
	 */
	private static function uninstall_site(): void {
		if ( ! self::should_remove_data() ) {
			return;
		}

		/**
		 * Fires while the plugin is being uninstalled on a single site, before
		 * the tables are dropped.
		 *
		 * Add-ons clean up their own storage here.
		 *
		 * @since 1.0.0
		 */
		do_action( 'formpilot_uninstall' );

		self::delete_uploads();
		self::delete_logs();

		Installer::drop_tables();

		delete_option( CronQueue::OPTION );
		delete_option( Settings::OPTION );

		delete_option( Activator::VERSION_OPTION );
		delete_option( Activator::INSTALLED_OPTION );
		delete_option( self::REMOVE_DATA_OPTION );

		self::delete_transients();
	}

	/**
	 * Removes the transients the plugin leaves scattered through the options table.
	 *
	 * These are not incidental. `formpilot_progress_*` holds **whatever the visitor
	 * typed** into a multi-step form, and used to survive an uninstall that had
	 * been explicitly told to delete the plugin's data — so the one thing an
	 * administrator was trying to remove was the thing left behind. The spam
	 * counters and the saved filters go too.
	 *
	 * Deleted by name pattern because transients have no registry. The object
	 * cache is flushed afterwards, since on a site with a persistent one the rows
	 * are only half the story.
	 */
	private static function delete_transients(): void {
		global $wpdb;

		foreach ( array( 'formpilot_progress_', 'formpilot_rate_', 'formpilot_interval_', 'formpilot_reply_', 'formpilot_entries_', 'formpilot_installing', 'formpilot_notification_queue_lock' ) as $prefix ) {
			// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Uninstall cleanup; transients have no registry to ask.
			$wpdb->query(
				$wpdb->prepare(
					"DELETE FROM {$wpdb->options} WHERE option_name LIKE %s OR option_name LIKE %s",
					$wpdb->esc_like( '_transient_' . $prefix ) . '%',
					$wpdb->esc_like( '_transient_timeout_' . $prefix ) . '%'
				)
			);
		}

		// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- See above.
		$wpdb->query(
			$wpdb->prepare(
				"DELETE FROM {$wpdb->options} WHERE option_name LIKE %s",
				$wpdb->esc_like( 'formpilot_' ) . '%'
			)
		);

		/*
		 * Per-user storage has no name pattern in the options table at all, so it
		 * has to be named. The saved entry filters live in user meta, which neither
		 * the prefix sweep nor the blanket delete above can reach, so they were left
		 * behind entirely by an uninstall told to remove the plugin's data.
		 */
		delete_metadata( 'user', 0, SavedFilters::META_KEY, '', true );

		// The per-page screen options. Named here rather than read from the list
		// tables, which extend WP_List_Table, a class uninstall does not load.
		delete_metadata( 'user', 0, 'formpilot_forms_per_page', '', true );
		delete_metadata( 'user', 0, 'formpilot_entries_per_page', '', true );

		/*
		 * Flushed because on a site with a persistent object cache the rows above
		 * are only half the story. This evicts more than this plugin owns, which is
		 * the price of not being able to enumerate what it cached - and it happens
		 * once, during an uninstall that has already dropped five tables.
		 */
		wp_cache_flush();
	}

	/**
	 * Removes the plugin upload directory.
	 *
	 * Files registered in the media library are left alone: they belong to the
	 * site once they appear there, and deleting them would break attachments.
	 */
	private static function delete_uploads(): void {
		$directory = UploadManager::base_dir();

		if ( '' === $directory || ! is_dir( $directory ) ) {
			return;
		}

		if ( ! function_exists( 'WP_Filesystem' ) ) {
			require_once ABSPATH . 'wp-admin/includes/file.php';
		}

		WP_Filesystem();

		global $wp_filesystem;

		if ( $wp_filesystem instanceof \WP_Filesystem_Base ) {
			$wp_filesystem->delete( $directory, true );
		}
	}

	/**
	 * Determines whether the stored plugin data should be deleted.
	 *
	 * @return bool True when the site owner opted into full removal.
	 */
	private static function should_remove_data(): bool {
		/**
		 * Filters whether the plugin data is removed on uninstall.
		 *
		 * @since 1.0.0
		 *
		 * @param bool $remove Whether to delete every plugin table and option.
		 */
		$opted_in = Settings::flag( 'remove_data' ) || (bool) get_option( self::REMOVE_DATA_OPTION, false );

		return (bool) apply_filters( 'formpilot_remove_data_on_uninstall', $opted_in );
	}
}