<?php
/**
 * Uninstall.
 *
 * The only place in the plugin that deletes anything. It does nothing at all
 * unless the site owner has switched on "remove all data", so deleting the
 * plugin by accident cannot take content with it.
 *
 * On a network every site makes that choice for itself: each site that
 * switched it on is cleaned, and every other site is left exactly as it is.
 * User meta is the exception, because users are shared by the whole network:
 * it goes only when every site that used the plugin switched it on.
 *
 * @package PageCore
 */

defined( 'WP_UNINSTALL_PLUGIN' ) || exit;

/*
 * WordPress deactivates a plugin before deleting it and loads nothing of it
 * but this file. The main file is loaded here so every module's uninstall
 * runs with the same services it uses while the plugin is active; a module
 * reaching for pagecore() would otherwise stop at that call and leave the
 * rest of its data behind.
 */
require_once __DIR__ . '/pagecore.php';

// An older PHP or WordPress stopped the plugin loading at all, and with it
// everything that knows what the plugin stored.
if ( ! function_exists( 'pagecore' ) ) {
	return;
}

/**
 * Whether the current site asked for its data to go with the plugin.
 *
 * @return bool
 */
function pagecore_uninstall_requested() {
	$settings = get_option( 'pagecore_settings', array() );

	return is_array( $settings ) && ! empty( $settings['remove_all_data'] );
}

/**
 * Whether PageCore stored anything at all on the current site.
 *
 * A site the plugin never ran on has nothing of its own to keep and never
 * made a choice, so it has no say over the data the network shares. Any
 * option with the plugin's prefix counts, except PageCore Pro's, which are
 * not this plugin's; activation alone is not enough, because activating
 * across a network seeds the main site only.
 *
 * @return bool
 */
function pagecore_uninstall_site_used() {
	global $wpdb;

	// phpcs:ignore WordPress.DB.DirectDatabaseQuery
	return (bool) $wpdb->get_var(
		$wpdb->prepare(
			"SELECT option_id FROM {$wpdb->options} WHERE option_name LIKE %s AND option_name NOT LIKE %s LIMIT 1",
			$wpdb->esc_like( 'pagecore_' ) . '%',
			$wpdb->esc_like( 'pagecore_pro_' ) . '%'
		)
	);
}

/**
 * Remove everything PageCore stored on the current site.
 *
 * @return void
 */
function pagecore_uninstall_site() {
	global $wpdb;

	/*
	 * Give every module the chance to remove what it created. A module that
	 * throws must not stop the others from cleaning up, so each call is
	 * guarded.
	 */
	foreach ( pagecore()->modules()->all() as $module ) {
		try {
			$module->uninstall();
		} catch ( Exception $e ) {
			continue;
		} catch ( Error $e ) {
			continue;
		}

		delete_option( 'pagecore_' . str_replace( '-', '_', $module->get_id() ) . '_settings' );
	}

	delete_option( 'pagecore_settings' );
	delete_option( 'pagecore_enabled_modules' );

	/*
	 * A module that has been deleted from disk, or one that threw on the way
	 * through the loop above, leaves its options behind with nothing left to
	 * know about them. This sweeps up anything still carrying the plugin's own
	 * prefix.
	 *
	 * Matched by prefix and escaped, so only options this plugin named can be
	 * reached, and nothing belonging to WordPress or to another plugin is in
	 * range of it. PageCore Pro's options start the same way and are left
	 * alone: they belong to Pro, and go when Pro itself is deleted.
	 */
	// phpcs:disable WordPress.DB.DirectDatabaseQuery
	$leftovers = $wpdb->get_col(
		$wpdb->prepare(
			"SELECT option_name FROM {$wpdb->options} WHERE option_name LIKE %s AND option_name NOT LIKE %s",
			$wpdb->esc_like( 'pagecore_' ) . '%',
			$wpdb->esc_like( 'pagecore_pro_' ) . '%'
		)
	);

	foreach ( (array) $leftovers as $option ) {
		delete_option( $option );
	}

	// Transients survive in the options table under two names each, so they
	// are swept the same way rather than guessed at.
	foreach ( array( '_transient_pagecore_', '_transient_timeout_pagecore_' ) as $prefix ) {
		$transients = $wpdb->get_col(
			$wpdb->prepare(
				"SELECT option_name FROM {$wpdb->options} WHERE option_name LIKE %s AND option_name NOT LIKE %s",
				$wpdb->esc_like( $prefix ) . '%',
				$wpdb->esc_like( $prefix . 'pro_' ) . '%'
			)
		);

		foreach ( (array) $transients as $option ) {
			delete_option( $option );
		}
	}

	/*
	 * Provenance stamps on anything the modules could not reach. These
	 * identify objects as PageCore's; with the plugin gone they identify
	 * nothing.
	 */
	// phpcs:disable WordPress.DB.SlowDBQuery.slow_db_query_meta_key -- Runs once, on uninstall.
	foreach ( array( '_pagecore_run_id', '_pagecore_demo', '_pagecore_source_id', '_pagecore_source_home', '_pagecore_modified_run_id', '_pagecore_modified_demo', '_pagecore_previous_content', '_pagecore_pending_thumbnail', '_pagecore_pending_parent', '_pagecore_source_content' ) as $key ) {
		$wpdb->delete( $wpdb->postmeta, array( 'meta_key' => $key ) );
		$wpdb->delete( $wpdb->termmeta, array( 'meta_key' => $key ) );
	}
	// phpcs:enable
}

$pagecore_cleaned = false;
$pagecore_kept    = false;

if ( is_multisite() ) {
	foreach ( get_sites(
		array(
			'fields' => 'ids',
			'number' => 0,
		)
	) as $pagecore_site_id ) {
		switch_to_blog( $pagecore_site_id );

		// Asked before the site is cleaned, since cleaning removes the very
		// options both questions read.
		if ( pagecore_uninstall_requested() ) {
			pagecore_uninstall_site();

			$pagecore_cleaned = true;
		} elseif ( pagecore_uninstall_site_used() ) {
			$pagecore_kept = true;
		}

		restore_current_blog();
	}
} elseif ( pagecore_uninstall_requested() ) {
	pagecore_uninstall_site();

	$pagecore_cleaned = true;
}

if ( $pagecore_cleaned ) {
	/*
	 * Library favorites. User meta is shared by every site on a network, so
	 * it is removed once, here, and only when no site that used the plugin
	 * chose to keep its data: one site removing its own data must not take
	 * another's favorites with it.
	 */
	if ( ! $pagecore_kept ) {
		delete_metadata( 'user', 0, 'pagecore_design_library_favorites', '', true );
	}

	wp_cache_flush();
}