<?php
/**
 * Plugin Name: QDR - Studiou WC Mail Queue
 * Plugin URI: https://www.quadarax.com/plugins/studiou-wc-mail-queue
 * Description: Intercepts outbound WooCommerce transactional mail and sends it through a persistent, rate-limited queue so bulk order-status changes cannot exceed the host's outbound mail limit.
 * Version: 1.0.0
 * Requires at least: 6.8
 * Tested up to: 6.9.4
 * Requires PHP: 8.2
 * WC requires at least: 9.8
 * WC tested up to: 10.9.4
 * Author: QUADARAX
 * Author URI: https://www.quadarax.com
 * License: GPL v2 or later
 * License URI: https://www.gnu.org/licenses/gpl-2.0.html
 * Text Domain: studiou-wc-mail-queue
 * Domain Path: /languages
 *
 * Copyright (C) 2026 QUADARAX. All rights reserved.
 * Contact: Dalibor Votruba <dvotruba@quadarax.com>
 *
 * This is an mu-plugin. It lives in a subdirectory and is loaded by the stub in
 * `loader/studiou-wc-mail-queue.php` — see that file for install instructions.
 *
 * @package studiou-wc-mail-queue
 * @copyright 2026 QUADARAX
 * @author    Dalibor Votruba <dvotruba@quadarax.com>
 * @license   GPL-2.0-or-later
 */

defined( 'ABSPATH' ) || exit;

define( 'STUDIOU_WCMQ_VERSION', '1.0.0' );
define( 'STUDIOU_WCMQ_FILE', __FILE__ );
define( 'STUDIOU_WCMQ_DIR', plugin_dir_path( __FILE__ ) );
define( 'STUDIOU_WCMQ_URL', plugin_dir_url( __FILE__ ) );
define( 'STUDIOU_WCMQ_BASENAME', plugin_basename( __FILE__ ) );

/**
 * Declare HPOS compatibility.
 *
 * Named (not a closure) so a test harness or another plugin can remove_action it.
 */
function studiou_wcmq_declare_hpos_compat() {
	if ( class_exists( \Automattic\WooCommerce\Utilities\FeaturesUtil::class ) ) {
		\Automattic\WooCommerce\Utilities\FeaturesUtil::declare_compatibility( 'custom_order_tables', STUDIOU_WCMQ_FILE, true );
	}
}
add_action( 'before_woocommerce_init', 'studiou_wcmq_declare_hpos_compat' );

/**
 * Main plugin class.
 *
 * Its only jobs: guard on WooCommerce, load dependencies, instantiate managers.
 * Managers register their own hooks in their constructors / init().
 */
final class Studiou_WC_Mail_Queue {

	/**
	 * Worker instance. Held so its hooks stay attached.
	 *
	 * @var Studiou_WCMQ_Worker|null
	 */
	private $worker = null;

	/**
	 * Admin instance.
	 *
	 * @var Studiou_WCMQ_Admin|null
	 */
	private $admin = null;

	/**
	 * Boot entry point.
	 */
	public static function init_plugin() {
		$class = __CLASS__;
		new $class();
	}

	/**
	 * Constructor.
	 */
	public function __construct() {
		if ( ! class_exists( 'WooCommerce' ) ) {
			add_action( 'admin_notices', array( $this, 'woocommerce_missing_notice' ) );
			return;
		}

		$this->load_dependencies();

		Studiou_WCMQ_DB::maybe_upgrade_db();

		Studiou_WCMQ_Utils_Log::init();
		Studiou_WCMQ_Context::init();
		Studiou_WCMQ_Interceptor::init();
		Studiou_WCMQ_State::init();
		Studiou_WCMQ_Reaper::init();
		Studiou_WCMQ_Retention::init();

		$this->worker = new Studiou_WCMQ_Worker();

		if ( is_admin() ) {
			$this->admin = new Studiou_WCMQ_Admin();
		}

		// Action Scheduler only exists once WooCommerce has loaded it. An mu-plugin
		// runs before regular plugins, so nothing AS-dependent may happen at file
		// scope or at plugins_loaded. Defer scheduling to `init`.
		add_action( 'init', array( $this, 'schedule_recurring_actions' ), 20 );
	}

	/**
	 * Load class files.
	 */
	private function load_dependencies() {
		$files = array(
			'utils-log.php',
			'class-wcmq-settings.php',
			'class-wcmq-db.php',
			'class-wcmq-state.php',
			'class-wcmq-context.php',
			'class-wcmq-queue.php',
			'class-wcmq-interceptor.php',
			'class-wcmq-notifier.php',
			'class-wcmq-worker.php',
			'class-wcmq-reaper.php',
			'class-wcmq-retention.php',
		);

		if ( is_admin() ) {
			$files[] = 'class-wcmq-admin.php';
		}

		foreach ( $files as $file ) {
			require_once STUDIOU_WCMQ_DIR . 'includes/' . $file;
		}
	}

	/**
	 * Register the recurring reaper + retention actions, exactly once each.
	 *
	 * Gated to admin / cron / WP-CLI. The `as_next_scheduled_action()` pre-check
	 * inside each is what keeps this idempotent, but it is still two DB queries,
	 * and running them on every front-end page view buys nothing: those contexts
	 * are exactly the ones that never need to bootstrap a schedule.
	 */
	public function schedule_recurring_actions() {
		if ( ! function_exists( 'as_schedule_recurring_action' ) ) {
			return;
		}
		$should_schedule = is_admin() || wp_doing_cron() || ( defined( 'WP_CLI' ) && WP_CLI );
		if ( ! $should_schedule ) {
			return;
		}
		Studiou_WCMQ_Reaper::schedule();
		Studiou_WCMQ_Retention::schedule();
	}

	/**
	 * Admin notice shown when WooCommerce is absent.
	 */
	public function woocommerce_missing_notice() {
		?>
		<div class="notice notice-error">
			<p><?php esc_html_e( 'Studiou WC Mail Queue requires WooCommerce to be installed and active.', 'studiou-wc-mail-queue' ); ?></p>
		</div>
		<?php
	}
}

/**
 * Load translations before anything instantiates.
 *
 * `load_plugin_textdomain()` resolves its relative path against WP_PLUGIN_DIR,
 * so for an mu-plugin it looks in `wp-content/plugins/...` — a directory that
 * does not exist here, and the catalogue silently never loads. The mu-plugin
 * equivalent, `load_muplugin_textdomain()`, resolves against WPMU_PLUGIN_DIR.
 *
 * Both check WP_LANG_DIR/plugins/ first, so a translation shipped by the site
 * still wins. The fallback keeps this working if the plugin is ever dropped into
 * wp-content/plugins/ as a regular plugin instead.
 */
function studiou_wcmq_load_textdomain() {
	$rel_path = basename( dirname( __FILE__ ) ) . '/languages';

	if ( load_muplugin_textdomain( 'studiou-wc-mail-queue', $rel_path ) ) {
		return;
	}

	load_plugin_textdomain( 'studiou-wc-mail-queue', false, $rel_path );
}
add_action( 'plugins_loaded', 'studiou_wcmq_load_textdomain', 5 );
add_action( 'plugins_loaded', array( 'Studiou_WC_Mail_Queue', 'init_plugin' ), 10 );