WP Global Cart - Scheduled currency price sync for WooCommerce products.

<?php


    /**
     * Scheduled currency price sync for WooCommerce products.
     *
     * Runs on a recurring WP-Cron schedule (default: once per day) and updates
     * the price of every product — simple, variable (per variation), external,
     * grouped, etc. — that carries both the '_origin_product_currency' and
     * '_origin_product_price' meta keys, converting the stored origin price
     * into the shop's current currency via WOOGC_Currency_Converter::convert().
     *
     * Products/variations missing EITHER meta key are skipped and the loop
     * continues to the next one.
     *
     * USAGE:
     * Paste this into a custom/mu-plugin file, or into your theme's
     * functions.php. Requires the plugin that provides WOOGC_Currency_Converter
     * to be active.
     */

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

    define( 'CUSTOM_PRICE_SYNC_HOOK', 'custom_price_sync_cron_hook' );


    add_filter( 'woogc/ps/synchronize_product/origin_product/meta_data', 'custom_woogc_add_site_currency', 10, 1 );
    function custom_woogc_add_site_currency( $args )
        {
            $product    =   wc_get_product( $args[ 'origin_product_id' ] );

            $args['product_meta']['_origin_product_currency'][] = get_option( 'woocommerce_currency' );
            $args['product_meta']['_origin_product_price'][]    = $product->get_price();

            return $args;
        }


    /**
     *
     * Change the interval via the 'custom_price_sync_interval_seconds' filter,
     * e.g. add_filter( 'custom_price_sync_interval_seconds', fn() => HOUR_IN_SECONDS * 6 );
     *
     * NOTE: if you change this after the event is already scheduled, run
     * custom_price_sync_unschedule_event() once (or deactivate/reactivate)
     * so WordPress picks up the new interval — WP doesn't reschedule an
     * already-queued event automatically.
     */
    add_filter( 'cron_schedules', 'custom_price_sync_register_interval' );
    function custom_price_sync_register_interval( $schedules ) {
        $schedules['custom_price_sync_interval'] = array(
            'interval' => apply_filters( 'custom_price_sync_interval_seconds', DAY_IN_SECONDS ),
            'display'  => __( 'Custom Price Sync Interval', 'custom-price-sync' ),
        );
        return $schedules;
    }

    /**
     * Schedule the event if it isn't already scheduled.
     */
    add_action( 'init', 'custom_price_sync_schedule_event' );
    function custom_price_sync_schedule_event() {
        if ( ! wp_next_scheduled( CUSTOM_PRICE_SYNC_HOOK ) ) {
            wp_schedule_event( time(), 'custom_price_sync_interval', CUSTOM_PRICE_SYNC_HOOK );
        }
    }

    /**
     * Unschedule helper — call this from a plugin deactivation hook if you turn
     * this into its own plugin file:
     *   register_deactivation_hook( __FILE__, 'custom_price_sync_unschedule_event' );
     */
    function custom_price_sync_unschedule_event() {
        $timestamp = wp_next_scheduled( CUSTOM_PRICE_SYNC_HOOK );
        if ( $timestamp ) {
            wp_unschedule_event( $timestamp, CUSTOM_PRICE_SYNC_HOOK );
        }
    }

    /**
     * The cron callback: loops through every product in batches and updates
     * prices for any product/variation carrying the origin currency/price meta.
     */
    add_action( CUSTOM_PRICE_SYNC_HOOK, 'custom_price_sync_run' );
    function custom_price_sync_run() {

        if ( ! class_exists( 'WOOGC_Currency_Converter' ) ) {
            custom_price_sync_log( 'WOOGC_Currency_Converter class not found. Aborting sync.' );
            return;
        }

        $batch_size = apply_filters( 'custom_price_sync_batch_size', 300 );
        $paged      = 1;

        do {
            $query = new WP_Query( array(
                'post_type'              => 'product',
                'post_status'            => 'publish',
                'posts_per_page'         => $batch_size,
                'paged'                  => $paged,
                'fields'                 => 'ids',
                'orderby'                => 'ID',
                'order'                  => 'ASC',
                'no_found_rows'          => true,
                'update_post_meta_cache' => false,
                'update_post_term_cache' => false,
            ) );

            if ( empty( $query->posts ) ) {
                break;
            }

            foreach ( $query->posts as $product_id ) {

                $product = wc_get_product( $product_id );

                if ( ! $product ) {
                    continue;
                }

                if ( $product->is_type( 'variable' ) ) {

                    $updated_any_variation = false;

                    foreach ( $product->get_children() as $variation_id ) {
                        $variation = wc_get_product( $variation_id );

                        if ( ! $variation ) {
                            continue;
                        }

                        if ( custom_price_sync_maybe_update_product( $variation ) ) {
                            $updated_any_variation = true;
                        }
                    }

                    // Refresh the parent's cached price range after variations change.
                    if ( $updated_any_variation && class_exists( 'WC_Product_Variable' ) ) {
                        WC_Product_Variable::sync( $product_id );
                        wc_delete_product_transients( $product_id );
                    }
                } else {
                    // Simple, external, grouped, etc.
                    custom_price_sync_maybe_update_product( $product );
                }
            }

            $paged++;

        } while ( true );

        custom_price_sync_log( 'Price sync run completed.' );
    }

    /**
     * Updates a single product/variation's price from its origin currency/price
     * meta, if both metas exist. Returns true if the price was updated.
     *
     * @param WC_Product $product
     * @return bool
     */
    function custom_price_sync_maybe_update_product( $product ) {

        $product_id = $product->get_id();

        // Skip products that don't have BOTH meta keys set (this is the correct
        // existence check — get_post_meta()/get_meta() return '' both when a
        // meta is missing AND when it's set to an empty string).
        if ( ! metadata_exists( 'post', $product_id, '_origin_product_currency' )
            || ! metadata_exists( 'post', $product_id, '_origin_product_price' ) ) {
            return false;
        }

        $origin_currency = $product->get_meta( '_origin_product_currency', true );
        $origin_price    = $product->get_meta( '_origin_product_price', true );

        if ( '' === $origin_currency || '' === $origin_price || ! is_numeric( $origin_price ) ) {
            custom_price_sync_log( sprintf( 'Product #%d has invalid origin meta, skipping.', $product_id ) );
            return false;
        }

        $shop_currency = get_option( 'woocommerce_currency' );

        // Nothing to convert if origin currency already matches the shop currency.
        if ( $origin_currency === $shop_currency ) {
            $new_price = floatval( $origin_price );
        } else {
            $new_price = WOOGC_Currency_Converter::convert(
                floatval( $origin_price ),
                $origin_currency,
                $shop_currency
            );

            if ( false === $new_price ) {
                custom_price_sync_log( sprintf(
                    'Currency conversion failed for product #%d (%s -> %s), skipping.',
                    $product_id,
                    $origin_currency,
                    $shop_currency
                ) );
                return false;
            }
        }

        $new_price = wc_format_decimal( $new_price, wc_get_price_decimals() );

        $old_regular_price = $product->get_regular_price();
        $old_sale_price    = $product->get_sale_price();

        $product->set_regular_price( $new_price );

        // If there's no active sale price, keep the active price in sync too.
        // (If a sale price exists, we leave it as-is rather than guessing a new one.)
        if ( '' === $old_sale_price ) {
            $product->set_price( $new_price );
        }

        $product->save();

        custom_price_sync_log( sprintf(
            'Product #%d price updated: %s %s -> %s %s (regular price %s -> %s).',
            $product_id,
            $origin_price,
            $origin_currency,
            $new_price,
            $shop_currency,
            $old_regular_price,
            $new_price
        ) );

        return true;
    }

    /**
     * Simple logging helper — writes to WooCommerce > Status > Logs
     * (source: custom-price-sync). Disable with:
     *   add_filter( 'custom_price_sync_enable_logging', '__return_false' );
     */
    function custom_price_sync_log( $message ) {
        if ( ! apply_filters( 'custom_price_sync_enable_logging', true ) ) {
            return;
        }

        if ( function_exists( 'wc_get_logger' ) ) {
            wc_get_logger()->info( $message, array( 'source' => 'custom-price-sync' ) );
        }
    }