woothemes/woocommerce

<?php
/**
 * Background Emailer
 *
 * @version 3.0.1
 * @package WooCommerce\Classes
 */

use Automattic\Jetpack\Constants;

defined( 'ABSPATH' ) || exit;

if ( ! class_exists( 'WC_Background_Process', false ) ) {
    include_once dirname( __FILE__ ) . '/abstracts/class-wc-background-process.php';
}

/**
 * WC_Background_Emailer Class.
 */
class WC_Background_Emailer extends WC_Background_Process {

    /**
     * Initiate new background process.
     */
    public function __construct() {
        // Uses unique prefix per blog so each blog has separate queue.
        $this->prefix = 'wp_' . get_current_blog_id();
        $this->action = 'wc_emailer';

        // Dispatch queue after shutdown.
        add_action( 'shutdown', array( $this, 'dispatch_queue' ), 100 );

        parent::__construct();
    }

    /**
     * Schedule fallback event.
     */
    protected function schedule_event() {
        if ( ! wp_next_scheduled( $this->cron_hook_identifier ) ) {
            wp_schedule_event( time() + 10, $this->cron_interval_identifier, $this->cron_hook_identifier );
        }
    }

    /**
     * Task
     *
     * Override this method to perform any actions required on each
     * queue item. Return the modified item for further processing
     * in the next pass through. Or, return false to remove the
     * item from the queue.
     *
     * @param array $callback Update callback function.
     * @return mixed
     */
    protected function task( $callback ) {
        if ( isset( $callback['filter'], $callback['args'] ) ) {
            try {
                WC_Emails::send_queued_transactional_email( $callback['filter'], $callback['args'] );
            } catch ( Exception $e ) {
                if ( Constants::is_true( 'WP_DEBUG' ) ) {
                    trigger_error( 'Transactional email triggered fatal error for callback ' . esc_html( $callback['filter'] ), E_USER_WARNING ); // phpcs:ignore WordPress.PHP.DevelopmentFunctions.error_log_trigger_error
                }
            }
        }
        return false;
    }

    /**
     * Finishes replying to the client, but keeps the process running for further (async) code execution.
     *
     * @see https://core.trac.wordpress.org/ticket/41358 .
     */
    protected function close_http_connection() {
        // Only 1 PHP process can access a session object at a time, close this so the next request isn't kept waiting.
        // @codingStandardsIgnoreStart
        if ( session_id() ) {
            session_write_close();
        }
        // @codingStandardsIgnoreEnd

        wc_set_time_limit( 0 );

        // fastcgi_finish_request is the cleanest way to send the response and keep the script running, but not every server has it.
        if ( is_callable( 'fastcgi_finish_request' ) ) {
            fastcgi_finish_request();
        } else {
            // Fallback: send headers and flush buffers.
            if ( ! headers_sent() ) {
                header( 'Connection: close' );
            }
            @ob_end_flush(); // phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged
            flush();
        }
    }

    /**
     * Save and run queue.
     */
    public function dispatch_queue() {
        if ( ! empty( $this->data ) ) {
            $this->close_http_connection();
            $this->save()->dispatch();
        }
    }

    /**
     * Get post args
     *
     * @return array
     */
    protected function get_post_args() {
        if ( property_exists( $this, 'post_args' ) ) {
            return $this->post_args;
        }

        // Pass cookies through with the request so nonces function.
        $cookies = array();

        foreach ( $_COOKIE as $name => $value ) { // WPCS: input var ok.
            if ( 'PHPSESSID' === $name ) {
                continue;
            }
            $cookies[] = new WP_Http_Cookie( array(
                'name'  => $name,
                'value' => $value,
            ) );
        }

        return array(
            'timeout'   => 0.01,
            'blocking'  => false,
            'body'      => $this->data,
            'cookies'   => $cookies,
            'sslverify' => apply_filters( 'https_local_ssl_verify', false ),
        );
    }

    /**
     * Handle
     *
     * Pass each queue item to the task handler, while remaining
     * within server memory and time limit constraints.
     */
    protected function handle() {
        $this->lock_process();

        do {
            $batch = $this->get_batch();

            if ( empty( $batch->data ) ) {
                break;
            }

            foreach ( $batch->data as $key => $value ) {
                $task = $this->task( $value );

                if ( false !== $task ) {
                    $batch->data[ $key ] = $task;
                } else {
                    unset( $batch->data[ $key ] );
                }

                // Update batch before sending more to prevent duplicate email possibility.
                $this->update( $batch->key, $batch->data );

                if ( $this->time_exceeded() || $this->memory_exceeded() ) {
                    // Batch limits reached.
                    break;
                }
            }
            if ( empty( $batch->data ) ) {
                $this->delete( $batch->key );
            }
        } while ( ! $this->time_exceeded() && ! $this->memory_exceeded() && ! $this->is_queue_empty() );

        $this->unlock_process();

        // Start next batch or complete process.
        if ( ! $this->is_queue_empty() ) {
            $this->dispatch();
        } else {
            $this->complete();
        }
    }
}