<?php
/**
 * Schema upgrade module.
 *
 * @package FormPilot
 * @since   1.0.0
 */

declare( strict_types = 1 );

namespace FormPilot\Database;

use FormPilot\Contracts\Hookable;
use WP_Site;

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

/**
 * Keeps the schema in sync on sites where the activation hook never runs.
 *
 * The activation hook only fires on the site that activated the plugin, so
 * upgrades delivered through the WordPress updater, plugins dropped in by
 * deployment tooling, and sites added to a network afterwards all rely on this
 * module instead.
 *
 * @since 1.0.0
 */
final class Migrator implements Hookable {

	/**
	 * Registers the module hooks.
	 */
	public function register_hooks(): void {
		add_action( 'admin_init', array( $this, 'maybe_upgrade' ) );
		add_action( 'wp_initialize_site', array( $this, 'install_new_site' ), 20, 1 );
		add_filter( 'wpmu_drop_tables', array( $this, 'drop_site_tables' ) );
	}

	/**
	 * Upgrades the schema when the stored version is outdated.
	 */
	public function maybe_upgrade(): void {
		if ( wp_doing_ajax() || wp_installing() ) {
			return;
		}

		Installer::maybe_upgrade();
	}

	/**
	 * Installs the tables on a site created while the plugin is network active.
	 *
	 * @param WP_Site $site The newly created site.
	 */
	public function install_new_site( WP_Site $site ): void {
		if ( ! function_exists( 'is_plugin_active_for_network' ) ) {
			require_once ABSPATH . 'wp-admin/includes/plugin.php';
		}

		if ( ! is_plugin_active_for_network( FORMPILOT_PLUGIN_BASENAME ) ) {
			return;
		}

		switch_to_blog( (int) $site->blog_id );
		Installer::install();
		restore_current_blog();
	}

	/**
	 * Adds the plugin tables to those dropped when a network site is deleted.
	 *
	 * Core drops only the tables it knows about, so deleting a subsite left its
	 * five plugin tables - every entry anyone had submitted there - in the
	 * database with nothing left pointing at them. Core has already switched to
	 * the site being deleted when it applies this filter, so the prefix is right.
	 *
	 * @param mixed $tables Tables core is about to drop.
	 *
	 * @return array<int|string, string> The tables, the plugin's included.
	 */
	public function drop_site_tables( mixed $tables ): array {
		$tables = is_array( $tables ) ? $tables : array();

		foreach ( Schema::tables() as $table ) {
			$tables[] = Schema::table( $table );
		}

		return $tables;
	}
}