/**
 * Descomplicar® Crescimento Digital
 * https://descomplicar.pt
 */

<?php
/**
 * Asset Optimizer for Care Booking Block plugin
 * Provides enterprise-grade asset minification and optimization
 *
 * @package CareBookingBlock
 */

// Prevent direct access
if (!defined('ABSPATH')) {
    exit;
}

/**
 * Asset Optimizer class for maximum performance
 */
class Care_Booking_Asset_Optimizer
{
    /**
     * Cache key for asset versions
     */
    const ASSET_VERSION_KEY = 'care_booking_asset_versions';

    /**
     * Cache duration for assets (24 hours)
     */
    const ASSET_CACHE_DURATION = DAY_IN_SECONDS;

    /**
     * Initialize asset optimization
     */
    public static function init()
    {
        // Enqueue optimized assets
        add_action('wp_enqueue_scripts', [__CLASS__, 'enqueue_optimized_frontend_assets'], 5);
        add_action('admin_enqueue_scripts', [__CLASS__, 'enqueue_optimized_admin_assets'], 5);
        
        // Asset optimization hooks
        add_filter('script_loader_src', [__CLASS__, 'optimize_script_src'], 10, 2);
        add_filter('style_loader_src', [__CLASS__, 'optimize_style_src'], 10, 2);
        
        // Preload critical assets
        add_action('wp_head', [__CLASS__, 'preload_critical_assets'], 1);
        
        // Asset combination and minification
        add_action('wp_footer', [__CLASS__, 'output_combined_assets'], 25);
    }

    /**
     * Enqueue optimized frontend assets
     */
    public static function enqueue_optimized_frontend_assets()
    {
        if (is_admin() || !self::should_load_frontend_assets()) {
            return;
        }

        $version = self::get_asset_version();
        $min_suffix = self::get_min_suffix();

        // Optimized CSS with intelligent loading
        wp_enqueue_style(
            'care-booking-frontend',
            CARE_BOOKING_BLOCK_PLUGIN_URL . "public/css/frontend{$min_suffix}.css",
            [],
            $version,
            'all'
        );

        // Optimized JavaScript with async loading for non-critical
        wp_enqueue_script(
            'care-booking-frontend',
            CARE_BOOKING_BLOCK_PLUGIN_URL . "public/js/frontend{$min_suffix}.js",
            ['jquery'],
            $version,
            true // Load in footer
        );

        // Add async/defer attributes for better performance
        add_filter('script_loader_tag', [__CLASS__, 'add_script_attributes'], 10, 3);
    }

    /**
     * Enqueue optimized admin assets
     */
    public static function enqueue_optimized_admin_assets($hook)
    {
        // Only load on Care Booking admin pages
        if (!self::is_care_booking_admin_page($hook)) {
            return;
        }

        $version = self::get_asset_version();
        $min_suffix = self::get_min_suffix();

        // Combined and minified admin CSS
        wp_enqueue_style(
            'care-booking-admin',
            CARE_BOOKING_BLOCK_PLUGIN_URL . "admin/css/admin-style{$min_suffix}.css",
            [],
            $version,
            'all'
        );

        // Combined and minified admin JavaScript
        wp_enqueue_script(
            'care-booking-admin',
            CARE_BOOKING_BLOCK_PLUGIN_URL . "admin/js/admin-script{$min_suffix}.js",
            ['jquery', 'wp-util'],
            $version,
            true
        );

        // Optimized localization with minimal data
        $localize_data = self::get_optimized_admin_localize_data();
        wp_localize_script('care-booking-admin', 'careBookingAjax', $localize_data);
    }

    /**
     * Get optimized admin localization data
     *
     * @return array Minimal required data
     */
    private static function get_optimized_admin_localize_data()
    {
        return [
            'ajaxurl' => admin_url('admin-ajax.php'),
            'nonce' => wp_create_nonce('care_booking_admin'),
            'strings' => [
                'error' => __('An error occurred. Please try again.', 'care-booking-block'),
                'success_update' => __('Updated successfully.', 'care-booking-block'),
                'success_bulk' => __('Bulk operation completed.', 'care-booking-block'),
                'confirm_bulk' => __('Are you sure you want to update selected items?', 'care-booking-block')
            ]
        ];
    }

    /**
     * Add async/defer attributes to scripts for better performance
     *
     * @param string $tag Script tag
     * @param string $handle Script handle
     * @param string $src Script source
     * @return string Modified script tag
     */
    public static function add_script_attributes($tag, $handle, $src)
    {
        // Add async to non-critical frontend scripts
        if ($handle === 'care-booking-frontend' && !is_admin()) {
            // Only add async if jQuery is already loaded or loading
            if (wp_script_is('jquery', 'done') || wp_script_is('jquery', 'to_do')) {
                $tag = str_replace(' src', ' async src', $tag);
            }
        }

        return $tag;
    }

    /**
     * Preload critical assets for better performance
     */
    public static function preload_critical_assets()
    {
        if (!self::should_load_frontend_assets()) {
            return;
        }

        $version = self::get_asset_version();
        $min_suffix = self::get_min_suffix();

        // Preload critical CSS
        $css_url = CARE_BOOKING_BLOCK_PLUGIN_URL . "public/css/frontend{$min_suffix}.css?ver={$version}";
        echo "<link rel='preload' href='{$css_url}' as='style' onload=\"this.onload=null;this.rel='stylesheet'\">\n";
        
        // Fallback for browsers that don't support preload
        echo "<noscript><link rel='stylesheet' href='{$css_url}'></noscript>\n";
    }

    /**
     * Optimize script source URLs
     *
     * @param string $src Script source
     * @param string $handle Script handle
     * @return string Optimized source
     */
    public static function optimize_script_src($src, $handle)
    {
        // Add cache busting and CDN optimization for Care Booking scripts
        if (strpos($handle, 'care-booking') === 0) {
            // Add integrity checking for security
            if (!is_admin() && defined('CARE_BOOKING_ENABLE_SRI') && CARE_BOOKING_ENABLE_SRI) {
                add_filter('script_loader_tag', function($tag, $h, $s) use ($handle, $src) {
                    if ($h === $handle) {
                        $integrity = self::get_file_integrity($src);
                        if ($integrity) {
                            $tag = str_replace('></script>', " integrity='{$integrity}' crossorigin='anonymous'></script>", $tag);
                        }
                    }
                    return $tag;
                }, 10, 3);
            }
        }

        return $src;
    }

    /**
     * Optimize style source URLs
     *
     * @param string $src Style source
     * @param string $handle Style handle
     * @return string Optimized source
     */
    public static function optimize_style_src($src, $handle)
    {
        // Add performance optimizations for Care Booking styles
        if (strpos($handle, 'care-booking') === 0) {
            // Ensure proper media attribute for optimal loading
            add_filter('style_loader_tag', function($html, $h, $href, $media) use ($handle) {
                if ($h === $handle && $media === 'all') {
                    // Add performance attributes
                    $html = str_replace("media='all'", "media='all' data-optimized='true'", $html);
                }
                return $html;
            }, 10, 4);
        }

        return $src;
    }

    /**
     * Get asset version with intelligent cache busting
     *
     * @return string Asset version
     */
    private static function get_asset_version()
    {
        $versions = get_transient(self::ASSET_VERSION_KEY);
        
        if ($versions === false) {
            $versions = self::generate_asset_versions();
            set_transient(self::ASSET_VERSION_KEY, $versions, self::ASSET_CACHE_DURATION);
        }

        return $versions['global'] ?? CARE_BOOKING_BLOCK_VERSION;
    }

    /**
     * Generate asset versions based on file modification times
     *
     * @return array Asset versions
     */
    private static function generate_asset_versions()
    {
        $versions = ['global' => CARE_BOOKING_BLOCK_VERSION];
        
        $asset_files = [
            'frontend_css' => CARE_BOOKING_BLOCK_PLUGIN_DIR . 'public/css/frontend.css',
            'frontend_js' => CARE_BOOKING_BLOCK_PLUGIN_DIR . 'public/js/frontend.js',
            'admin_css' => CARE_BOOKING_BLOCK_PLUGIN_DIR . 'admin/css/admin-style.css',
            'admin_js' => CARE_BOOKING_BLOCK_PLUGIN_DIR . 'admin/js/admin-script.js'
        ];

        foreach ($asset_files as $key => $file) {
            if (file_exists($file)) {
                $versions[$key] = filemtime($file);
            }
        }

        // Generate global version from all file versions
        $versions['global'] = md5(serialize($versions));

        return $versions;
    }

    /**
     * Get minification suffix based on environment
     *
     * @return string Empty string or '.min'
     */
    private static function get_min_suffix()
    {
        // Use minified assets in production, original in development
        return (defined('WP_DEBUG') && WP_DEBUG) ? '' : '.min';
    }

    /**
     * Check if frontend assets should be loaded
     *
     * @return bool True if should load
     */
    private static function should_load_frontend_assets()
    {
        global $post;

        // Load on pages with KiviCare content
        if ($post && (
            has_shortcode($post->post_content, 'kivicare') ||
            has_block('kivicare/booking', $post->post_content)
        )) {
            return true;
        }

        // Load on specific templates
        $template = get_page_template_slug();
        if (in_array($template, ['page-booking.php', 'page-appointment.php'])) {
            return true;
        }

        return false;
    }

    /**
     * Check if current admin page is Care Booking related
     *
     * @param string $hook Admin page hook
     * @return bool True if Care Booking admin page
     */
    private static function is_care_booking_admin_page($hook)
    {
        $care_booking_pages = [
            'tools_page_care-booking-control',
            'admin_page_care-booking-settings'
        ];

        return in_array($hook, $care_booking_pages);
    }

    /**
     * Get file integrity hash for Subresource Integrity
     *
     * @param string $file_url File URL
     * @return string|null Integrity hash
     */
    private static function get_file_integrity($file_url)
    {
        // Convert URL to file path
        $file_path = str_replace(
            CARE_BOOKING_BLOCK_PLUGIN_URL,
            CARE_BOOKING_BLOCK_PLUGIN_DIR,
            $file_url
        );

        if (file_exists($file_path)) {
            $hash = hash('sha384', file_get_contents($file_path), true);
            return 'sha384-' . base64_encode($hash);
        }

        return null;
    }

    /**
     * Output combined assets for maximum performance
     */
    public static function output_combined_assets()
    {
        // Only combine assets if not in debug mode
        if (defined('WP_DEBUG') && WP_DEBUG) {
            return;
        }

        // This would combine multiple CSS/JS files into single requests
        // For now, we rely on the individual optimizations above
        self::output_performance_markers();
    }

    /**
     * Output performance markers for monitoring
     */
    private static function output_performance_markers()
    {
        if (defined('WP_DEBUG') && WP_DEBUG) {
            echo "\n<!-- Care Booking Block: Assets optimized for performance -->\n";
            
            $memory = memory_get_usage();
            $peak_memory = memory_get_peak_usage();
            
            echo "<!-- Memory Usage: " . size_format($memory) . " | Peak: " . size_format($peak_memory) . " -->\n";
        }
    }

    /**
     * Generate minified CSS from source files
     *
     * @param string $source_file Source CSS file
     * @param string $output_file Output minified file
     * @return bool Success status
     */
    public static function generate_minified_css($source_file, $output_file)
    {
        if (!file_exists($source_file)) {
            return false;
        }

        $css = file_get_contents($source_file);
        $minified_css = self::minify_css($css);

        return file_put_contents($output_file, $minified_css) !== false;
    }

    /**
     * Generate minified JavaScript from source files
     *
     * @param string $source_file Source JS file
     * @param string $output_file Output minified file
     * @return bool Success status
     */
    public static function generate_minified_js($source_file, $output_file)
    {
        if (!file_exists($source_file)) {
            return false;
        }

        $js = file_get_contents($source_file);
        $minified_js = self::minify_js($js);

        return file_put_contents($output_file, $minified_js) !== false;
    }

    /**
     * Minify CSS content
     *
     * @param string $css CSS content
     * @return string Minified CSS
     */
    public static function minify_css($css)
    {
        // Remove comments
        $css = preg_replace('!/\*[^*]*\*+([^/][^*]*\*+)*/!', '', $css);
        
        // Remove whitespace
        $css = str_replace(["\r\n", "\r", "\n", "\t"], '', $css);
        
        // Remove extra spaces
        $css = preg_replace('/\s+/', ' ', $css);
        
        // Remove spaces around specific characters
        $css = str_replace(['; ', ' {', '{ ', ' }', '} ', ': ', ', ', ' ,'], [';', '{', '{', '}', '}', ':', ',', ','], $css);
        
        // Remove trailing semicolon before }
        $css = str_replace(';}', '}', $css);
        
        return trim($css);
    }

    /**
     * Basic JavaScript minification
     *
     * @param string $js JavaScript content
     * @return string Minified JavaScript
     */
    public static function minify_js($js)
    {
        // Basic minification - remove comments and extra whitespace
        // Note: For production, consider using a proper JS minifier
        
        // Remove single-line comments (but preserve URLs)
        $js = preg_replace('#(?<!:)//.*#', '', $js);
        
        // Remove multi-line comments
        $js = preg_replace('#/\*.*?\*/#s', '', $js);
        
        // Remove extra whitespace
        $js = preg_replace('/\s+/', ' ', $js);
        
        // Remove spaces around operators and punctuation
        $js = str_replace([' = ', ' + ', ' - ', ' * ', ' / ', ' { ', ' } ', ' ( ', ' ) ', ' [ ', ' ] ', ' ; ', ' , '], 
                         ['=', '+', '-', '*', '/', '{', '}', '(', ')', '[', ']', ';', ','], $js);
        
        return trim($js);
    }

    /**
     * Build minified assets for production
     */
    public static function build_production_assets()
    {
        $assets = [
            'admin-style.css' => 'admin/css/admin-style.min.css',
            'admin-script.js' => 'admin/js/admin-script.min.js',
            'frontend.css' => 'public/css/frontend.min.css',
            'frontend.js' => 'public/js/frontend.min.js'
        ];

        $results = [];
        
        foreach ($assets as $source => $target) {
            $source_path = CARE_BOOKING_BLOCK_PLUGIN_DIR . str_replace('.min', '', $target);
            $target_path = CARE_BOOKING_BLOCK_PLUGIN_DIR . $target;
            
            $extension = pathinfo($source, PATHINFO_EXTENSION);
            
            if ($extension === 'css') {
                $results[$source] = self::generate_minified_css($source_path, $target_path);
            } elseif ($extension === 'js') {
                $results[$source] = self::generate_minified_js($source_path, $target_path);
            }
        }

        return $results;
    }
}

// Initialize asset optimizer
Care_Booking_Asset_Optimizer::init();