<?php
/**
 * Common helper functions.
 *
 * @package WP_Recache
 */

defined('ABSPATH') || exit;

/**
 * Check if cache is enabled.
 */
function wp_recache_is_cache_enabled() {
    return (bool) get_option('wp_recache_cache_enabled', true);
}

/**
 * Check if a specific feature is enabled.
 *
 * @param string $feature Feature name.
 */
function wp_recache_is_feature_enabled($feature) {
    return (bool) get_option("wp_recache_{$feature}_enabled", false);
}

/**
 * Get plugin option with default.
 *
 * @param string $option Option name.
 * @param mixed  $default Default value.
 */
function wp_recache_get_option($option, $default = false) {
    return get_option("wp_recache_{$option}", $default);
}

/**
 * Set plugin option.
 *
 * @param string $option Option name.
 * @param mixed  $value Option value.
 */
function wp_recache_set_option($option, $value) {
    return update_option("wp_recache_{$option}", $value);
}

/**
 * Check if current user is logged in.
 */
function wp_recache_is_logged_in() {
    return is_user_logged_in();
}

/**
 * Check if current request should be excluded from cache.
 */
function wp_recache_should_exclude() {
    if (wp_recache_is_logged_in()) {
        return true;
    }

    // Dynamic query-string requests are never cached (story 11).
    if (!empty($_SERVER['QUERY_STRING'])) {
        return true;
    }

    if (is_preview() || is_feed() || is_404()) {
        return true;
    }

    if (wp_recache_is_post_action()) {
        return true;
    }

    $exclude_urls = wp_recache_get_option('exclude_urls', []);
    $request_uri = wp_parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);

    foreach ($exclude_urls as $url) {
        if (strpos($request_uri, trim($url)) !== false) {
            return true;
        }
    }

    return apply_filters('wp_recache_exclude', false);
}

/**
 * Check if request is for a robot/crawler.
 */
function wp_recache_is_robots() {
    return isset($_SERVER['HTTP_USER_AGENT']) && strpos($_SERVER['HTTP_USER_AGENT'], 'bot') !== false;
}

/**
 * Check if request is a POST action.
 */
function wp_recache_is_post_action() {
    return ($_SERVER['REQUEST_METHOD'] ?? 'GET') === 'POST';
}

/**
 * Get cache file path for URL.
 *
 * Keyed by md5(host + path) so nested paths, hosts and multisite
 * sub-directories never collide. Query strings are bypassed upstream.
 *
 * @param string $url URL to cache.
 */
function wp_recache_get_cache_path($url) {
    $host = (string) wp_parse_url($url, PHP_URL_HOST);
    $path = (string) wp_parse_url($url, PHP_URL_PATH);

    return WP_RECACHE_CACHE_PATH . md5($host . $path) . '.html';
}

/**
 * Delete cache file for URL.
 *
 * @param string $url URL to delete cache for.
 */
function wp_recache_delete_cache($url) {
    $path = wp_recache_get_cache_path($url);

    if (file_exists($path)) {
        return unlink($path);
    }

    return false;
}

/**
 * Delete all cache files.
 */
function wp_recache_delete_all_cache() {
    $cache_path = WP_RECACHE_CACHE_PATH;

    if (!is_dir($cache_path)) {
        return false;
    }

    $files = new RecursiveIteratorIterator(
        new RecursiveDirectoryIterator($cache_path, RecursiveDirectoryIterator::SKIP_DOTS),
        RecursiveIteratorIterator::CHILD_FIRST
    );

    foreach ($files as $file) {
        if ($file->isDir()) {
            rmdir($file->getRealPath());
        } else {
            unlink($file->getRealPath());
        }
    }

    return true;
}

/**
 * Check if URL is mobile.
 */
function wp_recache_is_mobile() {
    if (!isset($_SERVER['HTTP_USER_AGENT'])) {
        return false;
    }

    $mobile_agents = [
        'android',
        'iphone',
        'ipad',
        'ipod',
        'blackberry',
        'opera mini',
        'opera mobi',
    ];

    $user_agent = strtolower($_SERVER['HTTP_USER_AGENT']);

    foreach ($mobile_agents as $agent) {
        if (strpos($user_agent, $agent) !== false) {
            return true;
        }
    }

    return false;
}

/**
 * Get cache file path for URL with mobile detection.
 *
 * @param string $url URL to cache.
 */
function wp_recache_get_cache_path_with_device($url) {
    $path = wp_recache_get_cache_path($url);

    if (wp_recache_get_option('separate_mobile_cache', false)) {
        $device = wp_recache_is_mobile() ? 'mobile' : 'desktop';
        $path = str_replace('.html', "-{$device}.html", $path);
    }

    return $path;
}

/**
 * Enqueue the admin-bar purge script (admin and front-end admin bar).
 */
function wp_recache_enqueue_admin_bar_script() {
    if (!is_admin_bar_showing() || !current_user_can('manage_options')) {
        return;
    }

    wp_enqueue_script('wp-recache-admin', WP_RECACHE_URL . 'assets/admin.js', ['jquery'], WP_RECACHE_VERSION, true);
    wp_localize_script('wp-recache-admin', 'wpRecache', [
        'ajaxUrl' => admin_url('admin-ajax.php'),
        'nonce' => wp_create_nonce('wp_recache_nonce'),
    ]);
}