<?php
/**
 * Personal data export and erasure (gift messages).
 *
 * @package Extrova
 */

declare( strict_types=1 );

namespace Extrova\Order;

defined( 'ABSPATH' ) || exit;

/**
 * Gift messages are personal data. Registers an exporter and an eraser and anonymises them
 * when WooCommerce anonymises an order.
 *
 * @since 1.0.0
 */
final class Privacy {

	private const BATCH = 10;

	/**
	 * Registers the exporter (`wp_privacy_personal_data_exporters`).
	 *
	 * @param array $exporters Exporters.
	 */
	public function register_exporter( $exporters ): array {
		$exporters            = is_array( $exporters ) ? $exporters : array();
		$exporters['extrova'] = array(
			'exporter_friendly_name' => __( 'Extrova (order messages)', 'extrova' ),
			'callback'               => array( $this, 'export' ),
		);
		return $exporters;
	}

	/**
	 * Registers the eraser (`wp_privacy_personal_data_erasers`).
	 *
	 * @param array $erasers Erasers.
	 */
	public function register_eraser( $erasers ): array {
		$erasers            = is_array( $erasers ) ? $erasers : array();
		$erasers['extrova'] = array(
			'eraser_friendly_name' => __( 'Extrova (order messages)', 'extrova' ),
			'callback'             => array( $this, 'erase' ),
		);
		return $erasers;
	}

	/**
	 * Orders of a customer (same query as WooCommerce's own exporter; HPOS compatible).
	 *
	 * @param string $email Email.
	 * @param int    $page  Page.
	 * @return \WC_Order[]
	 */
	private function orders( string $email, int $page ): array {
		$customer = array( $email );
		$user     = get_user_by( 'email', $email );
		if ( $user instanceof \WP_User ) {
			$customer[] = (int) $user->ID;
		}
		$orders = wc_get_orders(
			array(
				'limit'    => self::BATCH,
				'page'     => max( 1, $page ),
				'customer' => $customer,
			)
		);
		return is_array( $orders ) ? array_filter( $orders, static fn( mixed $o ): bool => $o instanceof \WC_Order ) : array();
	}

	/**
	 * Text items of an order snapshot.
	 *
	 * @param \WC_Order $order Order.
	 */
	private function text_items( \WC_Order $order ): array {
		$snapshot = $order->get_meta( OrderWriter::META_SNAPSHOT, true );
		if ( ! is_array( $snapshot ) || ! isset( $snapshot['items'] ) || ! is_array( $snapshot['items'] ) ) {
			return array();
		}
		return array_filter(
			$snapshot['items'],
			static fn( mixed $item ): bool => is_array( $item ) && 'text' === ( $item['type'] ?? '' ) && '' !== (string) ( $item['display_value'] ?? '' )
		);
	}

	/**
	 * Exporter callback.
	 *
	 * @param string $email Email.
	 * @param int    $page  Page.
	 */
	public function export( $email, $page = 1 ): array {
		$orders = $this->orders( (string) $email, (int) $page );
		$data   = array();
		foreach ( $orders as $order ) {
			$fields = array();
			foreach ( $this->text_items( $order ) as $item ) {
				$fields[] = array(
					'name'  => (string) $item['label'],
					'value' => (string) $item['display_value'],
				);
			}
			if ( array() !== $fields ) {
				$data[] = array(
					'group_id'    => 'extrova',
					'group_label' => __( 'Order extras', 'extrova' ),
					'item_id'     => 'extrova-order-' . $order->get_id(),
					'data'        => $fields,
				);
			}
		}
		return array(
			'data' => $data,
			'done' => count( $orders ) < self::BATCH,
		);
	}

	/**
	 * Eraser callback. Respects WooCommerce's "Remove personal data from orders on request" setting.
	 *
	 * @param string $email Email.
	 * @param int    $page  Page.
	 */
	public function erase( $email, $page = 1 ): array {
		$orders   = $this->orders( (string) $email, (int) $page );
		$allowed  = 'yes' === get_option( 'woocommerce_erasure_request_removes_order_data', 'no' );
		$removed  = false;
		$retained = false;
		$messages = array();

		foreach ( $orders as $order ) {
			if ( array() === $this->text_items( $order ) ) {
				continue;
			}
			if ( ! $allowed ) {
				$retained = true;
				continue;
			}
			$this->anonymize( $order );
			$order->save();
			$removed = true;
		}

		if ( $retained ) {
			$messages[] = __( 'Order messages were retained because order data is not removed on erasure requests (WooCommerce > Settings > Accounts & Privacy).', 'extrova' );
		}

		return array(
			'items_removed'  => $removed,
			'items_retained' => $retained,
			'messages'       => $messages,
			'done'           => count( $orders ) < self::BATCH,
		);
	}

	/**
	 * Anonymises text values (`woocommerce_privacy_remove_order_personal_data`). WooCommerce saves the order afterwards.
	 *
	 * @param mixed $order Order.
	 */
	public function anonymize( $order ): void {
		if ( ! $order instanceof \WC_Order ) {
			return;
		}
		$snapshot = $order->get_meta( OrderWriter::META_SNAPSHOT, true );
		if ( ! is_array( $snapshot ) || ! isset( $snapshot['items'] ) || ! is_array( $snapshot['items'] ) ) {
			return;
		}
		$changed = false;
		$ids     = array();
		foreach ( $snapshot['items'] as $index => $item ) {
			if ( is_array( $item ) && 'text' === ( $item['type'] ?? '' ) ) {
				$snapshot['items'][ $index ]['value']         = wp_privacy_anonymize_data( 'text', '' );
				$snapshot['items'][ $index ]['display_value'] = wp_privacy_anonymize_data( 'text', '' );
				$ids[ (string) ( $item['extra_id'] ?? '' ) ]  = true;
				$changed                                      = true;
			}
		}
		if ( ! $changed ) {
			return;
		}
		$order->update_meta_data( OrderWriter::META_SNAPSHOT, $snapshot );

		foreach ( $order->get_fees() as $fee_item ) {
			if ( $fee_item instanceof \WC_Order_Item_Fee && isset( $ids[ (string) $fee_item->get_meta( OrderWriter::ITEM_META_ID, true ) ] ) ) {
				$fee_item->update_meta_data( OrderWriter::ITEM_META_VALUE, wp_privacy_anonymize_data( 'text', '' ) );
				$fee_item->save();
			}
		}
	}
}