<?php
/**
 * Every menu item with an active rule, in both menu systems.
 *
 * @package Yangra\Conditional
 */

namespace Yangra\Conditional\Menus;

use Yangra\Conditional\Index\ContentIndex;
use Yangra\Conditional\Rules\RuleSanitizer;

defined( 'ABSPATH' ) || exit;

/**
 * Lists the menu items whose rule is on and has conditions: classic menu items
 * from their `_yangra_conditional_rule` meta, and Navigation items from the
 * content index (published and private content only), newest first.
 */
class MenuItemsWithRules {

	/**
	 * Rule sanitizer.
	 *
	 * @var RuleSanitizer
	 */
	private $sanitizer;

	/**
	 * Content index.
	 *
	 * @var ContentIndex
	 */
	private $index;

	/**
	 * Constructor.
	 *
	 * @param RuleSanitizer $sanitizer Rule sanitizer.
	 * @param ContentIndex  $index     Content index.
	 */
	public function __construct( RuleSanitizer $sanitizer, ContentIndex $index ) {
		$this->sanitizer = $sanitizer;
		$this->index     = $index;
	}

	/**
	 * Every menu item with an active rule, most recently changed menu first,
	 * then in menu order.
	 *
	 * `menu` is where the item is: a classic menu's ID, or the ID of the post
	 * that holds the Navigation block (a Navigation menu, template, template
	 * part or other content).
	 *
	 * @return array<int, array{key: string, label: string, source: string, menu: int, menu_name: string, menu_type: string, edit_url: string, rule: array<string, mixed>, modified: int}>
	 */
	public function all(): array {
		$items = array_merge( $this->classic(), $this->navigation() );

		// usort() isn't stable on PHP 7.4, so ties keep their menu order by position.
		$order = array_flip( array_column( $items, 'key' ) );
		usort(
			$items,
			static function ( array $a, array $b ) use ( $order ): int {
				return array( $b['modified'], $order[ $a['key'] ] ) <=> array( $a['modified'], $order[ $b['key'] ] );
			}
		);

		return $items;
	}

	/**
	 * Whether a sanitized rule is on and has at least one condition.
	 *
	 * @param array<string, mixed> $rule Sanitized rule.
	 * @return bool
	 */
	public static function is_active( array $rule ): bool {
		if ( empty( $rule['enabled'] ) ) {
			return false;
		}

		foreach ( (array) ( $rule['groups'] ?? array() ) as $group ) {
			if ( ! empty( $group['conditions'] ) ) {
				return true;
			}
		}

		return false;
	}

	/**
	 * Classic menu items with an active rule. Items not saved in a menu yet
	 * (drafts) are left out.
	 *
	 * @return array<int, array{key: string, label: string, source: string, menu: int, menu_name: string, menu_type: string, edit_url: string, rule: array<string, mixed>, modified: int}>
	 */
	private function classic(): array {
		$ids = get_posts(
			array(
				'post_type'      => 'nav_menu_item',
				'post_status'    => 'publish',
				'posts_per_page' => -1,
				'fields'         => 'ids',
				'orderby'        => 'menu_order',
				'order'          => 'ASC',
				'no_found_rows'  => true,
				'meta_key'       => ClassicMenuFilter::META_KEY, // phpcs:ignore WordPress.DB.SlowDBQuery.slow_db_query_meta_key -- Admin only, menu items with a rule.
			)
		);
		$ids = array_map( 'intval', $ids );
		update_meta_cache( 'post', $ids );
		update_object_term_cache( $ids, 'nav_menu_item' );

		$items = array();
		foreach ( $ids as $id ) {
			$rule = $this->sanitizer->sanitize( get_post_meta( $id, ClassicMenuFilter::META_KEY, true ) );
			$post = get_post( $id );
			$menu = get_the_terms( $id, 'nav_menu' );
			if ( ! self::is_active( $rule ) || null === $post || ! is_array( $menu ) || array() === $menu ) {
				continue;
			}

			$item    = wp_setup_nav_menu_item( $post );
			$items[] = array(
				'key'       => 'classic-' . $id,
				'label'     => trim( html_entity_decode( wp_strip_all_tags( (string) ( $item->title ?? '' ) ), ENT_QUOTES, 'UTF-8' ) ),
				'source'    => 'classic',
				'menu'      => (int) $menu[0]->term_id,
				'menu_name' => $menu[0]->name,
				'menu_type' => __( 'Classic menu', 'yangra-conditional' ),
				'edit_url'  => admin_url( 'nav-menus.php?action=edit&menu=' . (int) $menu[0]->term_id ),
				'rule'      => $rule,
				'modified'  => (int) strtotime( $post->post_modified_gmt . ' UTC' ),
			);
		}

		return $items;
	}

	/**
	 * Navigation items with an active rule, from the content index.
	 *
	 * @return array<int, array{key: string, label: string, source: string, menu: int, menu_name: string, menu_type: string, edit_url: string, rule: array<string, mixed>, modified: int}>
	 */
	private function navigation(): array {
		$items = array();
		foreach ( $this->index->live_posts() as $post_id => $index ) {
			$list = isset( $index['menu_list'] ) && is_array( $index['menu_list'] ) ? $index['menu_list'] : array();
			$post = array() === $list ? null : get_post( $post_id );
			if ( null === $post ) {
				continue;
			}

			$type = get_post_type_object( $post->post_type );
			foreach ( $list as $position => $entry ) {
				$rule = $this->sanitizer->sanitize( $entry['rule'] ?? null );
				if ( ! self::is_active( $rule ) ) {
					continue;
				}

				$items[] = array(
					'key'       => 'navigation-' . $post_id . '-' . $position,
					'label'     => isset( $entry['label'] ) ? (string) $entry['label'] : '',
					'source'    => 'navigation',
					'menu'      => (int) $post_id,
					'menu_name' => trim( html_entity_decode( wp_strip_all_tags( $post->post_title ), ENT_QUOTES, 'UTF-8' ) ),
					'menu_type' => null !== $type ? (string) $type->labels->singular_name : $post->post_type,
					'edit_url'  => (string) get_edit_post_link( $post_id, 'raw' ),
					'rule'      => $rule,
					'modified'  => (int) strtotime( $post->post_modified_gmt . ' UTC' ),
				);
			}
		}

		return $items;
	}
}