<?php
/**
 * Drag-and-drop manual ordering on the FAQ admin list table.
 *
 * @package AccordionFaq
 */

namespace AccordionFaq\Admin;

defined( 'ABSPATH' ) || exit;

use AccordionFaq\Setup\PostType;
use AccordionFaq\Setup\Meta;

/**
 * Class OrderList
 */
class OrderList {

	const ACTION = 'accordion_faq_reorder';
	const NONCE  = 'accordion_faq_reorder';

	/**
	 * Register hooks.
	 *
	 * @return void
	 */
	public function register() {
		add_action( 'pre_get_posts', array( $this, 'default_order' ) );
		add_action( 'admin_enqueue_scripts', array( $this, 'enqueue' ) );
		add_action( 'wp_ajax_' . self::ACTION, array( $this, 'save' ) );
	}

	/**
	 * Default the FAQ admin list to manual order (and show them all on one
	 * screen so a drag reorders the whole set), unless the user picked a
	 * sortable column.
	 *
	 * @param \WP_Query $query Query.
	 * @return void
	 */
	public function default_order( $query ) {
		if ( ! is_admin() || ! $query->is_main_query() ) {
			return;
		}
		if ( PostType::POST_TYPE !== $query->get( 'post_type' ) ) {
			return;
		}
		if ( $query->get( 'orderby' ) ) {
			return; // Respect an explicit column sort or search.
		}

		$query->set( 'orderby', 'meta_value_num' );
		$query->set( 'meta_key', Meta::META_ORDER ); // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_key
		$query->set( 'order', 'ASC' );
		// Include FAQs that have no order meta yet (treated as 0).
		$query->set(
			'meta_query', // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_query
			array(
				'relation' => 'OR',
				array(
					'key'     => Meta::META_ORDER,
					'compare' => 'EXISTS',
				),
				array(
					'key'     => Meta::META_ORDER,
					'compare' => 'NOT EXISTS',
				),
			)
		);
		$query->set( 'posts_per_page', 500 );
	}

	/**
	 * Enqueue the sortable script on the FAQ list screen.
	 *
	 * @param string $hook Current admin page.
	 * @return void
	 */
	public function enqueue( $hook ) {
		if ( 'edit.php' !== $hook ) {
			return;
		}
		$screen = function_exists( 'get_current_screen' ) ? get_current_screen() : null;
		if ( ! $screen || PostType::POST_TYPE !== $screen->post_type ) {
			return;
		}
		if ( ! current_user_can( 'edit_others_posts' ) ) {
			return;
		}

		$js = ACCORDION_FAQ_PATH . 'assets/admin/js/reorder.js';
		wp_enqueue_script(
			'accordion-faq-reorder',
			ACCORDION_FAQ_URL . 'assets/admin/js/reorder.js',
			array( 'jquery', 'jquery-ui-sortable' ),
			is_readable( $js ) ? (string) filemtime( $js ) : ACCORDION_FAQ_VERSION,
			true
		);
		wp_localize_script(
			'accordion-faq-reorder',
			'AccordionFaqReorder',
			array(
				'ajax'   => admin_url( 'admin-ajax.php' ),
				'action' => self::ACTION,
				'nonce'  => wp_create_nonce( self::NONCE ),
				'saving' => __( 'Saving order…', 'accordion-faq-plugin' ),
				'saved'  => __( 'Order saved.', 'accordion-faq-plugin' ),
				'failed' => __( 'Could not save the new order.', 'accordion-faq-plugin' ),
			)
		);
	}

	/**
	 * Persist a new manual order (AJAX).
	 *
	 * @return void
	 */
	public function save() {
		if ( ! check_ajax_referer( self::NONCE, 'nonce', false ) ) {
			wp_send_json_error( array( 'message' => 'bad_nonce' ), 403 );
		}
		if ( ! current_user_can( 'edit_others_posts' ) ) {
			wp_send_json_error( array( 'message' => 'forbidden' ), 403 );
		}

		$ids = isset( $_POST['order'] ) ? array_map( 'absint', (array) wp_unslash( $_POST['order'] ) ) : array();
		$ids = array_values( array_filter( $ids ) );
		if ( empty( $ids ) ) {
			wp_send_json_error( array( 'message' => 'empty' ), 400 );
		}

		$position = 1;
		foreach ( $ids as $id ) {
			if ( PostType::POST_TYPE !== get_post_type( $id ) ) {
				continue;
			}
			update_post_meta( $id, Meta::META_ORDER, $position );
			$position++;
		}

		wp_send_json_success( array( 'count' => count( $ids ) ) );
	}
}