<?php
/**
 * Polling for sites Telegram cannot call: once a minute, fetch new updates with getUpdates and
 * hand each to the same handler the webhook uses. The offset is saved after every update, so
 * an update is never handled twice even if a run is cut short.
 *
 * @package Orderchirp
 */

namespace Orderchirp;

defined( 'ABSPATH' ) || exit;

final class Poller {

	const HOOK          = 'orderchirp_poll';
	const OFFSET_OPTION = 'orderchirp_poll_offset';
	const INTERVAL      = 60;

	/**
	 * Hook in.
	 */
	public function register() {
		add_action( self::HOOK, array( __CLASS__, 'poll' ) );
		// Self-heal: polling mode with no scheduled job (e.g. Action Scheduler tables were reset).
		if ( 'polling' === Settings::get( 'delivery' ) && Settings::connected() ) {
			add_action( 'admin_init', array( __CLASS__, 'schedule' ) );
		}
	}

	/**
	 * Start polling.
	 */
	public static function schedule() {
		if ( function_exists( 'as_has_scheduled_action' ) && ! as_has_scheduled_action( self::HOOK, array(), Dispatcher::GROUP ) ) {
			as_schedule_recurring_action( time() + 5, self::INTERVAL, self::HOOK, array(), Dispatcher::GROUP );
		}
	}

	/**
	 * Stop polling.
	 */
	public static function unschedule() {
		if ( function_exists( 'as_unschedule_all_actions' ) ) {
			as_unschedule_all_actions( self::HOOK, array(), Dispatcher::GROUP );
		}
	}

	/**
	 * One poll.
	 *
	 * @return int Updates handled.
	 */
	public static function poll() {
		if ( ! Settings::connected() || 'polling' !== Settings::get( 'delivery' ) ) {
			return 0;
		}
		$result = Telegram_Api::from_settings()->call(
			'getUpdates',
			array(
				'offset'          => (int) get_option( self::OFFSET_OPTION, 0 ),
				'timeout'         => 0,
				'limit'           => 50,
				'allowed_updates' => array( 'message' ),
			)
		);
		if ( ! $result['ok'] || ! is_array( $result['result'] ) ) {
			return 0;
		}
		$handled = 0;
		foreach ( $result['result'] as $update ) {
			if ( ! is_array( $update ) || ! isset( $update['update_id'] ) ) {
				continue;
			}
			update_option( self::OFFSET_OPTION, (int) $update['update_id'] + 1, false );
			try {
				Updates_Handler::handle( $update );
			} catch ( \Throwable $e ) {
				// phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_error_log -- surfaced to the site's own error log only.
				error_log( 'Orderchirp: could not handle a Telegram update: ' . $e->getMessage() );
			}
			++$handled;
		}
		return $handled;
	}
}