<?php
/**
 * Uninstall behaviour is deliberately conservative: settings, counters and
 * scheduled jobs are removed, but request records are kept, because they belong
 * to a commercial trail that has a statutory retention period. Removing them is
 * an explicit, separate action.
 *
 * What is removed here is everything the plugin wrote *about itself*: its
 * options, the temporary keys behind its throttles and tickets, and every job
 * it put on the schedule. (It keeps nothing on a user: the admin speaks each
 * user's WordPress language, step-5 review.) Until 0.66.0
 * this list was two thirds complete — one of the three cron hooks stayed
 * registered, the key index and the counters it points at stayed in the options
 * table, and on a multisite the whole thing only ever ran for one site.
 *
 * No table is dropped unless the shop asked for it: the requests and the event
 * log stay (and the tables an add-on keeps beside them). Only a shop that ticked
 * "Delete all Careback data when the plugin is deleted" (N-104) has them go
 * too, with the key behind the email fingerprints and the data Careback saved on
 * orders (Data_Eraser); WooCommerce's orders and their notes always stay. The
 * settings — the plugin's option and those of its emails in WooCommerce — are
 * kept, and nothing of that is deleted, while another installed plugin declares
 * this one as a requirement: deleting this plugin while an add-on built on it
 * stays installed is not a decision about the store's settings or data. What an
 * add-on writes itself — its options, its scheduled jobs — its own uninstall
 * removes; none is named here.
 *
 * @package Careback
 */

defined( 'WP_UNINSTALL_PLUGIN' ) || exit;

/**
 * Everything one site holds. Called once on a single install, and once per site
 * on a network, so nothing is written twice and nothing is forgotten.
 */
function careback_uninstall_site() {
	global $wpdb;

	$dependents = careback_uninstall_has_dependents();
	// The shop's settings: the plugin's own and those of its three emails in
	// WooCommerce → Settings → Emails (step 6, N-69).
	$keep = $dependents ? array( 'careback_settings', 'woocommerce_careback_request_received_settings', 'woocommerce_careback_request_status_settings', 'woocommerce_careback_new_request_settings' ) : array();
	// "Delete all Careback data when the plugin is deleted" (N-104), read before
	// the settings go; never while a plugin that needs this one is installed.
	$settings = get_option( 'careback_settings', array() );
	$erase    = ! $dependents && is_array( $settings ) && ! empty( $settings['delete_data_on_uninstall'] );

	foreach (
		array(
			// Settings, and the schema version that decides whether to migrate.
			'careback_settings',
			'careback_db_version',
			// The index of throttle keys, and the lock the migration takes.
			'careback_limit_keys',
			'careback_upgrading',
			// Indexes the last upgrade could not add.
			'careback_index_gaps',
			// The parts of the schema the last table setup ran with.
			'careback_db_parts',
			// What the shop set for the plugin's emails in WooCommerce → Settings
			// → Emails: on/off, subject, heading, additional content, format,
			// recipients (step 6, N-69).
			'woocommerce_careback_request_received_settings',
			'woocommerce_careback_request_status_settings',
			'woocommerce_careback_new_request_settings',
		) as $option
	) {
		if ( in_array( $option, $keep, true ) ) {
			continue;
		}

		delete_option( $option );
	}

	// This plugin's own scheduled job. An add-on's jobs are cleared by its own
	// uninstall (and by its deactivation).
	foreach (
		array(
			'careback_retention',
		) as $hook
	) {
		wp_clear_scheduled_hook( $hook );

		// wp_clear_scheduled_hook() only matches events with no arguments. The
		// loop catches anything left with them, which a site's own code may have
		// scheduled against these hooks.
		$timestamp = wp_next_scheduled( $hook );

		while ( $timestamp ) {
			wp_unschedule_event( $timestamp, $hook );
			$timestamp = wp_next_scheduled( $hook );
		}
	}

	// Throttle counters, temporary blocks and spent-ticket markers are
	// transients. On a site with a persistent object cache they are not in the
	// options table at all and expire on their own; where they are, they would
	// otherwise sit there until their timeout, which for a ticket claim is an
	// ordinary option with no timeout at all.
	$prefixes = array( 'careback_rl_', 'careback_ban_', 'careback_jti_' );

	foreach ( $prefixes as $prefix ) {
		// esc_like() escapes underscores as well, which is why the prefix is
		// escaped rather than pasted in: `careback_rl_` would otherwise match `carebackXrlY`.
		$like = $wpdb->esc_like( $prefix ) . '%';

		$names = $wpdb->get_col( // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- no WordPress API lists options by name prefix; read live.
			$wpdb->prepare(
				"SELECT option_name FROM {$wpdb->options} WHERE option_name LIKE %s OR option_name LIKE %s OR option_name LIKE %s",
				$like,
				$wpdb->esc_like( '_transient_' . $prefix ) . '%',
				$wpdb->esc_like( '_transient_timeout_' . $prefix ) . '%'
			)
		);

		foreach ( (array) $names as $name ) {
			delete_option( $name );
		}
	}

	if ( $erase ) {
		if ( ! class_exists( '\Careback\Data_Eraser' ) ) {
			require_once __DIR__ . '/includes/class-data-eraser.php';
		}

		\Careback\Data_Eraser::erase();
	}
}

/**
 * True when another installed plugin names this one under "Requires Plugins"
 * (read by WordPress 6.5 and later; earlier versions report no dependents, and
 * the option goes as it always did).
 *
 * @return bool
 */
function careback_uninstall_has_dependents() {
	if ( ! function_exists( 'get_plugins' ) ) {
		require_once ABSPATH . 'wp-admin/includes/plugin.php';
	}

	$self = strtolower( dirname( (string) WP_UNINSTALL_PLUGIN ) );

	if ( '' === $self || '.' === $self ) {
		return false;
	}

	foreach ( get_plugins() as $file => $data ) {
		if ( (string) WP_UNINSTALL_PLUGIN === $file || empty( $data['RequiresPlugins'] ) ) {
			continue;
		}

		$required = array_map( 'trim', explode( ',', strtolower( (string) $data['RequiresPlugins'] ) ) );

		if ( in_array( $self, $required, true ) ) {
			return true;
		}
	}

	return false;
}

if ( is_multisite() ) {
	// A network install wrote its options per site, so they have to be removed
	// per site. Bounded, because get_sites() with no limit returns 100 by
	// default and a large network would otherwise be half cleaned.
	$careback_page = 1;

	do {
		$careback_sites = get_sites(
			array(
				'number' => 100,
				'offset' => ( $careback_page - 1 ) * 100,
				'fields' => 'ids',
			)
		);

		foreach ( $careback_sites as $careback_site_id ) {
			switch_to_blog( $careback_site_id );
			careback_uninstall_site();
			restore_current_blog();
		}

		$careback_page++;
	} while ( count( $careback_sites ) === 100 );
} else {
	careback_uninstall_site();
}