<?php
/**
 * Product CSV export and import of WooCommerce: the tabs of a product go out as two "Meta:" columns and come back
 * intact. WooCommerce leaves out the meta that are not plain values, and filters every meta column of an import as
 * post HTML: the tabs are written as JSON without tag, quote or ampersand characters, and written back once the
 * product is saved, the way the Tabs panel writes them.
 *
 * @package Prodtabs
 */

namespace Prodtabs;

defined( 'ABSPATH' ) || exit;

/**
 * Round trip of the tabs through the product CSV of WooCommerce.
 */
final class Woo_Csv {

	/** Meta exported and imported. */
	const KEYS = array( Tabs::META_LAYOUT, Tabs::META_TEXTS );

	/** Key of the parsed data that carries the tabs from parsing to saving. */
	const DATA = 'prodtabs_tabs';

	/** Hooks. */
	public static function init(): void {
		add_filter( 'woocommerce_product_export_meta_value', array( __CLASS__, 'export_value' ), 10, 2 );
		add_filter( 'woocommerce_product_export_skip_meta_keys', array( __CLASS__, 'skip_keys' ) );
		add_filter( 'woocommerce_product_importer_parsed_data', array( __CLASS__, 'parsed_data' ) );
		add_action( 'woocommerce_product_import_inserted_product_object', array( __CLASS__, 'write' ), 10, 2 );
	}

	/**
	 * Tabs as JSON in the export, each shared tab with its reference (see Transfer).
	 *
	 * @param mixed  $value Meta value.
	 * @param object $meta  Meta (key, value).
	 */
	public static function export_value( $value, $meta ) {
		if ( is_object( $meta ) && in_array( $meta->key ?? '', self::KEYS, true ) && is_array( $value ) ) {
			if ( Tabs::META_LAYOUT === $meta->key ) {
				$value = Transfer::export_layout( $value ); // Shared tabs with a reference that holds on another site.
			}
			return (string) wp_json_encode( $value, JSON_HEX_TAG | JSON_HEX_APOS | JSON_HEX_QUOT | JSON_HEX_AMP | JSON_UNESCAPED_UNICODE );
		}
		return $value;
	}

	/**
	 * Marks of the YIKES import stay out of the export: they describe this site only.
	 *
	 * @param array $keys Meta keys left out.
	 */
	public static function skip_keys( $keys ) {
		return array_merge( (array) $keys, array( Import_Yikes::META_IMPORTED, Import_Yikes::META_BACKUP ) );
	}

	/**
	 * Takes the tab columns out of the meta that WooCommerce writes, to write them once the product is saved.
	 *
	 * @param array $data Parsed row.
	 */
	public static function parsed_data( $data ) {
		if ( empty( $data['meta_data'] ) || ! is_array( $data['meta_data'] ) ) {
			return $data;
		}
		foreach ( $data['meta_data'] as $index => $meta ) {
			if ( ! isset( $meta['key'] ) || ! in_array( $meta['key'], self::KEYS, true ) ) {
				continue;
			}
			unset( $data['meta_data'][ $index ] );
			// The CSV value comes raw (no slashes added): the escapes of the JSON itself must stay.
			$value = is_string( $meta['value'] ?? null ) ? json_decode( $meta['value'], true ) : null;
			// An empty cell or a value that is not ours leaves the tabs of the product as they are.
			if ( is_array( $value ) ) {
				$data[ self::DATA ][ $meta['key'] ] = $value;
			}
		}
		$data['meta_data'] = array_values( $data['meta_data'] );
		return $data;
	}

	/**
	 * Writes the imported tabs, pointed to the shared tabs of this site. update_post_meta() removes one level of
	 * slashes: the value is slashed first.
	 *
	 * @param \WC_Product $product Imported product.
	 * @param array       $data    Parsed row.
	 */
	public static function write( $product, $data ): void {
		if ( empty( $data[ self::DATA ] ) || ! $product instanceof \WC_Product ) {
			return;
		}
		$id = $product->get_id();
		foreach ( $data[ self::DATA ] as $key => $value ) {
			if ( Tabs::META_LAYOUT === $key && is_array( $value ) ) {
				$value = Transfer::import_layout( $value ); // Shared tabs of this site, found by their reference.
			}
			if ( $value ) {
				update_post_meta( $id, $key, wp_slash( $value ) );
			} else {
				delete_post_meta( $id, $key );
			}
		}
		clean_post_cache( $id );
		wc_delete_product_transients( $id );
	}
}