<?php

/**
 * [Short Description (no period for file headers)]
 *
 * [Long Description.]
 *
 * @link https://github.com/inpsyde/menu-cache
 * @since 2.1.0
 *
 * @package ItalyStrap\Core
 */

namespace ItalyStrap\Cache;

use Inpsyde\MenuCache\MenuCache;

/**
 * Class description
 */
class Menu extends MenuCache
{
    private ?int $expiration = null;

    private string $key_prefix = 'cached_menu_';

    /**
     * @var string[]
     */
    private ?array $theme_locations = null;

    /**
     * Stores the menu HTML in a transient.
     *
     * @since   1.0.0
     * @wp-hook wp_nav_menu
     *
     * @param string $menu Menu HTML.
     * @param object $args Menu args.
     *
     * @return string Unfiltered menu HTML.
     */
    public function cache_menu($menu, $args)
    {

        $args = $this->normalize_args($args);

        if ($this->should_cache_menu($args)) {
            // set_transient( $this->get_key( $args ), $menu, $this->expiration() );
            wp_cache_set($this->get_key($args), $menu, 'menu', $this->expiration());
        }

        return $menu;
    }

    /**
     * Returns a cached menu, if found.
     *
     * @since   1.0.0
     * @wp-hook pre_wp_nav_menu
     *
     * @param null   $menu Unused.
     * @param object $args Menu args.
     *
     * @return string|null Cached menu HTML, if found, or null.
     */
    public function get_menu($menu, $args)
    {

        $args = $this->normalize_args($args);

        if ($this->should_cache_menu($args)) {
            // $cached_menu = get_transient( $this->get_key( $args ) );
            $cached_menu = wp_cache_get($this->get_key($args), 'menu');
            if (is_string($cached_menu)) {
                return $cached_menu;
            }
        }

        return $menu;
    }

    /**
     * Returns the expiration.
     *
     * @return int Expiration.
     */
    private function expiration()
    {

        if (isset($this->expiration)) {
            return $this->expiration;
        }

        /**
         * Filters the expiration.
         *
         * @param int $expiration Expiration in seconds.
         */
        $this->expiration = (int) apply_filters('inpsyde_menu_cache.expiration', 300);

        return $this->expiration;
    }

    /**
     * Returns a unique key for a menu (represented by its args).
     *
     * @param object $args Menu args.
     *
     * @return string Menu key.
     */
    private function get_key($args)
    {

        /**
         * Filters the key of a single menu.
         *
         * @param string $key  Current key.
         * @param object $args Menu args.
         */
        return (string) apply_filters('inpsyde_menu_cache.key', $this->key_prefix . md5(serialize($args)), $args);
    }

    /**
     * Returns a normalized version of the passed menu args object.
     *
     * @param object $args Menu args.
     *
     * @return object Normalized menu args.
     */
    private function normalize_args($args)
    {

        $menu = wp_get_nav_menu_object($args->menu);

        if (! $menu && $args->theme_location) {
            $locations = get_nav_menu_locations();
            if (isset($locations[ $args->theme_location ])) {
                $menu = wp_get_nav_menu_object($locations[ $args->theme_location ]);
            }
        }

        if (! $menu && ! $args->theme_location) {
            foreach (wp_get_nav_menus() as $menu_maybe) {
                if (wp_get_nav_menu_items($menu_maybe->term_id, ['update_post_term_cache' => false])) {
                    $menu = $menu_maybe;
                    break;
                }
            }
        }

        if (empty($args->menu)) {
            $args->menu = $menu;
        }

        return $args;
    }

    /**
     * Returns a unique key for a menu (represented by its args).
     *
     * @param object $args Menu args.
     *
     * @return bool Whether or not the menu should be cached.
     */
    private function should_cache_menu($args)
    {

        $should_cache_menu = true;

        if (! empty($args->theme_location)) {
            $theme_locations = $this->theme_locations();
            if ($theme_locations) {
                $should_cache_menu = in_array($args->theme_location, $theme_locations, true);
            }
        }

        /**
         * Filters the caching condition of a single menu.
         *
         * @param bool   $should_cache_menu Whether or not the menu should be cached.
         * @param object $args              Menu args.
         */
        return (bool) apply_filters('inpsyde_menu_cache.should_cache_menu', $should_cache_menu, $args);
    }

    /**
     * Returns the theme locations.
     *
     * @return string[] Theme locations.
     */
    private function theme_locations()
    {

        if (isset($this->theme_locations)) {
            return $this->theme_locations;
        }

        /**
         * Filters the theme locations.
         *
         * @param string|string[] $theme_locations One or more theme locations.
         */
        $this->theme_locations = (array) apply_filters('inpsyde_menu_cache.theme_locations', []);
        $this->theme_locations = array_map('strval', $this->theme_locations);

        return $this->theme_locations;
    }
}