<?php
/**
 * The delivery as plain custom fields on the order ("Delivery date", "Time", "Kind of delivery", extra fields…),
 * so the WooCommerce mobile app ("View custom fields") and other tools that skip hidden meta can see it.
 * Our own data stays in the hidden _dayslot_* meta; these copies are rewritten whenever the order is saved,
 * and filled in for older orders the first time the app (REST API) asks for them.
 */

defined( 'ABSPATH' ) || exit;

add_filter(
	'dayslot_default_settings',
	function ( $d ) {
		$d['app_fields'] = 'yes';
		return $d;
	}
);

define( 'DAYSLOT_APP_KEYS_META', '_dayslot_app_keys' );

/**
 * Label => value of the delivery, as the customer saw it.
 */
function dayslot_app_fields( $order ) {
	$out = array();
	foreach ( dayslot_order_summary_rows( $order ) as $row ) {
		$label = trim( wp_strip_all_tags( (string) $row['label'] ) );
		$value = trim( wp_strip_all_tags( (string) $row['value'] ) );
		if ( '' !== $label && '' !== $value && '_' !== $label[0] && ! isset( $out[ $label ] ) ) {
			$out[ $label ] = $value;
		}
	}
	return $out;
}

/**
 * Write the copies on the order (no save()); returns the fields. Old copies that no longer apply are removed.
 */
function dayslot_app_fields_sync( $order ) {
	$fields = 'yes' === dayslot_get_settings()['app_fields'] && $order->get_meta( DAYSLOT_META ) ? dayslot_app_fields( $order ) : array();
	$old    = (array) $order->get_meta( DAYSLOT_APP_KEYS_META );
	foreach ( array_diff( $old, array_keys( $fields ) ) as $key ) {
		$order->delete_meta_data( $key );
	}
	foreach ( $fields as $key => $value ) {
		if ( (string) $order->get_meta( $key ) !== $value ) {
			$order->update_meta_data( $key, $value );
		}
	}
	if ( $fields ) {
		if ( array_keys( $fields ) !== $old ) {
			$order->update_meta_data( DAYSLOT_APP_KEYS_META, array_keys( $fields ) );
		}
	} elseif ( $old ) {
		$order->delete_meta_data( DAYSLOT_APP_KEYS_META );
	}
	return $fields;
}

// Every save of an order with a delivery (checkout, admin change, calendar drag & drop, rescheduling).
add_action(
	'woocommerce_before_order_object_save',
	function ( $order ) {
		if ( $order instanceof WC_Order && ( $order->get_meta( DAYSLOT_META ) || $order->get_meta( DAYSLOT_APP_KEYS_META ) ) ) {
			dayslot_app_fields_sync( $order );
		}
	}
);

// Older orders: filled in when the mobile app (REST API) opens them.
add_filter(
	'woocommerce_rest_prepare_shop_order_object',
	function ( $response, $order ) {
		if ( 'yes' !== dayslot_get_settings()['app_fields'] || ! $order instanceof WC_Order || ! $order->get_meta( DAYSLOT_META ) || $order->get_meta( DAYSLOT_APP_KEYS_META ) ) {
			return $response;
		}
		$fields = dayslot_app_fields_sync( $order );
		$order->save();
		$data = $response->get_data();
		if ( isset( $data['meta_data'] ) && is_array( $data['meta_data'] ) ) {
			foreach ( $order->get_meta_data() as $meta ) {
				if ( isset( $fields[ $meta->key ] ) ) {
					$data['meta_data'][] = $meta;
				}
			}
			$response->set_data( $data );
		}
		return $response;
	},
	10,
	2
);