<?php

/**
 * Abovethefold optimization core class.
 *
 * This class provides the functionality for admin dashboard and WordPress hooks.
 *
 * @since      1.0
 * @package    abovethefold
 * @subpackage abovethefold/includes
 * @author     Optimization.Team <info@optimization.team>
 */

class Abovethefold
{

    /**
     * The loader that's responsible for maintaining and registering all hooks that power
     * the plugin
     */
    public $loader;

    /**
     * The unique identifier of this plugin
     */
    public $plugin_name;

    /**
     * The current version of the plugin
     */
    protected $version;

    /**
     * Disable abovethefold optimization
     */
    public $disabled = false;

    /**
     * Special view (e.g. full css export and critical css quality tester)
     */
    public $view = false;

    /**
     * Options
     */

    public $options;

    /**
     * Sub-controllers
     */
    public $admin;
    public $optimization;
    public $plugins;
    public $gwfo;
    public $proxy;
    public $lazy;

    /**
     * cURL controller
     */
    public $curl;

    /**
     * Template redirect hook called
     */
    public $template_redirect_called = false;

    /**
     * Construct and initiated Abovethefold class
     */
    public function __construct()
    {
        global $show_admin_bar;

        // set plugin meta
        $this->plugin_name = 'abovethefold';
        $this->version = WPABTF_VERSION;

        /**
         * Disable plugin in admin or for testing
         */
        if (!$this->is_enabled()) {
            $this->disabled = true;
        }

        /**
         * Register Activate / Deactivate hooks.
         */
        register_activation_hook(WPABTF_SELF, array( $this, 'activate' ));
        register_deactivation_hook(WPABTF_SELF, array( $this, 'deactivate' ));

        /**
         * Special Views
         */
        
        // a hash is used to prevent random traffic or abuse
        $view_hash = md5(SECURE_AUTH_KEY . AUTH_KEY);

        // available views
        $views = array(

            // extract full CSS view
            'extract-css' => array( 'admin_bar' => false ),

            // critical CSS quality test and editor
            'critical-css-editor' => array( 'admin_bar' => false, 'nohash' => true ),

            // view website with just the critical CSS
            'critical-css-view' => array( 'admin_bar' => false, 'nohash' => true ),

            // view website regularly, but without the admin toolbar for comparison view
            'full-css-view' => array( 'admin_bar' => false , 'nohash' => true ),

            // build tool HTML export for Gulp.js critical task
            'abtf-buildtool-html' => array( 'admin_bar' => false ),

            // build tool full css export for Gulp.js critical task
            'abtf-buildtool-css' => array( 'admin_bar' => false ),

            // external resource proxy
            'abtf-proxy' => array( )
        );
        foreach ($views as $viewKey => $viewSettings) {

            // check if view is active
            if (isset($_REQUEST[$viewKey])) {
                if ((!isset($viewSettings['nohash']) || !$viewSettings['nohash']) && $_REQUEST[$viewKey] !== $view_hash) {
                    continue;
                }

                // set view
                $this->view = $viewKey;

                // hide admin bar
                if (isset($viewSettings['admin_bar']) && $viewSettings['admin_bar'] === false) {
                    $show_admin_bar = false;
                }
            }
        }

        // load dependencies
        $this->load_dependencies();

        // Load WordPress hook/filter loader
        $this->loader = new Abovethefold_Loader();

        // set language
        $this->set_locale();

        /**
         * Load options
         */
        $this->options = get_option('abovethefold');

        // load Google PWA optimization controller
        $this->pwa = new Abovethefold_PWA($this);

        // load HTTP/2 optimization controller
        $this->http2 = new Abovethefold_HTTP2($this);

        // load webfont optimization controller
        $this->gwfo = new Abovethefold_WebFonts($this);

        /**
         * External resource proxy
         */
        $this->proxy = new Abovethefold_Proxy($this);

        /**
         * Load admin controller
         */
        $this->admin = new Abovethefold_Admin($this);

        // do not load rest of plugin for proxy
        if ($this->view === 'abtf-proxy') {
            return;
        }

        // plugin module controller
        $this->plugins = new Abovethefold_Plugins($this);
        $this->plugins->load_modules();

        /**
         * Critical CSS optimization controller
         */
        $this->criticalcss = new Abovethefold_Critical_CSS($this);

        // load optimization controller
        $this->optimization = new Abovethefold_Optimization($this);


        // load lazy script loading module
        $this->lazy = new Abovethefold_LazyScripts($this);

        /**
         * Use Above The Fold Optimization standard output buffer
         */
        $this->loader->add_action('template_redirect', $this, 'template_redirect', -10);

        // add noindex meta
        if (isset($_GET['noabtf'])) {

            // wordpress header
            $this->loader->add_action('wp_head', $this, 'header', 1);
        }

        /**
         * Setup cron
         */
        $this->loader->add_action('abtf_cron', $this, 'cron');
        $this->loader->add_action('wp', $this, 'setup_cron');
    }

    /**
     * Check if optimization should be applied to output
     */
    public function is_enabled()
    {

        /**
         * Disable for Google AMP pages
         */
        if (function_exists('is_amp_endpoint') && is_amp_endpoint()) {
            return false;
        }

        /**
         * Disable for REST API requests
         */
        if (defined('REST_REQUEST') && REST_REQUEST) {
            return false;
        }

        /**
         * Disable above the fold optimization
         */
        if (defined('DONOTABTF') && DONOTABTF) {
            return false;
        }

        /**
         * o10n Critical CSS Editor
         */
        if (isset($_GET['o10n-css']) || isset($_GET['o10n-no-css']) || isset($_GET['o10n-full-css'])) {
            return false;
        }

        /**
         * Skip if admin
         */
        if (defined('WP_ADMIN')) {
            return false;
        }

        /**
         * Skip if doing AJAX
         */
        if (defined('DOING_AJAX')) {
            return false;
        }

        /**
         * Skip if doing cron
         */
        if (defined('DOING_CRON')) {
            return false;
        }

        /**
         * Skip if APP request
         */
        if (defined('APP_REQUEST')) {
            return false;
        }

        /**
         * Skip if XMLRPC request
         */
        if (defined('XMLRPC_REQUEST')) {
            return false;
        }

        /**
         * Check for WPMU's and WP's 3.0 short init
         */
        if (defined('SHORTINIT') && SHORTINIT) {
            return false;
        }

        /**
         * Check if we're displaying feed
         */
        if ($this->template_redirect_called && is_feed()) {
            return false;
        }

        /**
         * Register or login page
         */
        if (isset($GLOBALS['pagenow']) && in_array($GLOBALS['pagenow'], array('wp-login.php', 'wp-register.php'))) {
            return false;
        }

        /**
         * Disable plugin with query string ?noabtf
         */
        if (isset($_GET['noabtf'])) {
            return false;
        }

        return true;
    }

    /**
     * Template redirect hook (required for is_feed() enabled check)
     */
    public function template_redirect()
    {

        // detect new optimization plugins
        if (defined('O10N_CORE_VERSION') && class_exists('\O10n\Core')) {
            $modules = O10n\Core::get('modules');
            if (in_array('css', $modules)) {
                define('O10N_CSS_MODULE_LOADED', true);
            }
            if (in_array('fonts', $modules)) {
                define('O10N_FONTS_MODULE_LOADED', true);
            }
            if (in_array('js', $modules)) {
                define('O10N_JS_MODULE_LOADED', true);

                add_action('o10n_script_text_pre', array($this->optimization, 'ignore_abtf'), 1, 2);
            }
        }

        // return content security hashes
        if (isset($_GET['abtf-csp-hash'])) {
            $json = array();

            $algorithms = array(
                'sha256',
                'sha384',
                'sha512'
            );

            // verify noonce
            /*if (!wp_verify_nonce($_GET['abtf-csp-hash'], 'csp_hash_json')) {
                foreach ($algorithms as $algorithm) {
                    $json[$algorithm] = array(
                        'public' => 'WORDPRESS_NONCE_AUTH_FAILED',
                        'debug' => 'WORDPRESS_NONCE_AUTH_FAILED'
                    );
                }
            } else {*/
            foreach ($algorithms as $algorithm) {
                try {
                    $json[$algorithm] = array(
                            'public' => $this->optimization->get_client_script_hash(false, $algorithm),
                            'debug' => $this->optimization->get_client_script_hash(true, $algorithm)
                        );
                } catch (Exception $err) {
                    $json[$algorithm] = array(
                            'public' => 'FAILED',
                            'debug' => 'FAILED'
                        );
                }
            }
            //}

            while (ob_get_level()) {
                ob_end_clean();
            }

            print json_encode($json);
            exit;
        }
        
        $this->template_redirect_called = true;

        /**
         * Disable plugin
         */
        if (!$this->is_enabled()) {
            $this->disabled = true;
        }
    }

    /**
     * Load the required dependencies
     */
    private function load_dependencies()
    {

        /**
         * The class responsible for orchestrating the actions and filters of the
         * core plugin
         */
        require_once WPABTF_PATH . 'includes/loader.class.php';

        /**
         * The class responsible for defining internationalization functionality
         * of the plugin
         */
        require_once WPABTF_PATH . 'includes/i18n.class.php';

        /**
         * The class responsible for defining all actions related to Google PWA optimization
         */
        require_once WPABTF_PATH . 'includes/pwa.class.php';

        /**
         * The class responsible for defining all actions related to HTTP2 optimization
         */
        require_once WPABTF_PATH . 'includes/http2.class.php';

        /**
         * The class responsible for defining all actions related to Web Font optimization
         */
        require_once WPABTF_PATH . 'includes/webfonts.class.php';

        /**
         * External resource proxy
         */
        require_once WPABTF_PATH . 'includes/proxy.class.php';

        /**
         * The class responsible for defining all actions that occur in the Dashboard.
         */
        require_once WPABTF_PATH . 'admin/admin.class.php';

        // do not load the rest of the dependencies for proxy
        if ($this->view === 'abtf-proxy') {
            return;
        }

        /**
         * The class responsible for defining all actions related to optimization.
         */
        require_once WPABTF_PATH . 'includes/optimization.class.php';

        /**
         * The class responsible for defining all actions related to critical css optimization.
         */
        require_once WPABTF_PATH . 'includes/critical-css.class.php';

        /**
         * The class responsible for defining all actions related to lazy script loading.
         */
        require_once WPABTF_PATH . 'includes/lazyscripts.class.php';

        /**
         * Extract Full CSS view
         */
        if (in_array($this->view, array('extract-css','abtf-buildtool-css'))) {

            /**
             * The class responsible for defining all actions related to full css extraction
             */
            require_once WPABTF_PATH . 'includes/extract-full-css.class.php';
        }

        /**
         * Critical CSS Quality Test view
         */
        if ($this->view === 'critical-css-editor') {

            /**
             * The class responsible for defining all actions related to compare critical CSS
             */
            require_once WPABTF_PATH . 'includes/critical-css-editor.class.php';
        }

        /**
         * The class responsible plugin extension modules.
         */
        require_once WPABTF_PATH . 'includes/plugins.class.php';
        require_once WPABTF_PATH . 'modules/plugins.class.php';
    }
    
    /**
     * Return url with view query string
     */
    public function view_url($view, $query = array(), $currenturl = false)
    {
        if (!$currenturl) {
            if (is_admin()
                || (defined('DOING_AJAX') && DOING_AJAX)
                || in_array($GLOBALS['pagenow'], array('wp-login.php', 'wp-register.php'))
            ) {
                $currenturl = home_url();
            } else {
                $currenturl = ((isset($_SERVER['HTTPS']) && $_SERVER['HTTPS']) ? 'https' : 'http') . '://' . $_SERVER['HTTP_HOST'] . $_SERVER['REQUEST_URI'];
            }
        }

        /**
         * Return url with view query string
         */

        switch ($view) {
            case "critical-css-editor":
            case "critical-css-view":
                $value = 1;
            break;
            default:
                $value = md5(SECURE_AUTH_KEY . AUTH_KEY);
            break;
        }

        return preg_replace('|\#.*$|Ui', '', $currenturl) . ((strpos($currenturl, '?') !== false) ? '&' : '?') . $view . '=' . $value . (!empty($query) ? '&' . http_build_query($query) : '');
    }

    /**
     * Define the locale for this plugin for internationalization.
     *
     * Uses the Abovethefold_i18n class in order to set the domain and to register the hook
     * with WordPress
     */
    private function set_locale()
    {
        $plugin_i18n = new Abovethefold_i18n();
        $plugin_i18n->set_domain($this->get_plugin_name());

        $this->loader->add_action('plugins_loaded', $plugin_i18n, 'load_plugin_textdomain');
    }

    /**
     * WordPress header
     */
    public function header()
    {
        print '<meta name="robots" content="noindex, nofollow" />';
    }

    /**
     * Run the loader to execute all of the hooks with WordPress
     */
    public function run()
    {
        $this->loader->run();

        /**
         * If proxy, start processing request
         */
        if ($this->view === 'abtf-proxy') {
            $this->proxy->handle_request();
        }
    }

    /**
     * The name of the plugin used to uniquely identify it within the context of
     * WordPress and to define internationalization functionality
     */
    public function get_plugin_name()
    {
        return $this->plugin_name;
    }

    /**
     * The reference to the class that orchestrates the hooks with the plugin
     */
    public function get_loader()
    {
        return $this->loader;
    }

    /**
     * Retrieve the version number of the plugin
     */
    public function get_version()
    {
        return $this->version;
    }

    /**
     * Create directory
     */
    public function mkdir($path, $mask = 0755)
    {
        if (!is_dir($path)) {
            if (!@mkdir($path, $mask)) {
                wp_die('Failed to write to: ' . $path);
            }
        }
        if (is_dir($path)) {
            chmod($path, $mask);

            return true;
        }

        return false; // error
    }

    /**
     * Remove directory
     */
    public function rmdir($dir)
    {
        if (!is_dir($dir)) {
            return false;
        }

        // restrict access to plugin directories
        if (strpos($dir, '/abtf/') === false && strpos($dir, '/abovethefold/') === false) {
            return false;
        }

        $files = array_diff(scandir($dir), array('.','..'));
        foreach ($files as $file) {
            (is_dir("$dir/$file")) ? $this->rmdir("$dir/$file") : @unlink("$dir/$file");
        }

        return @rmdir($dir);
    }

    /**
     * File put contents
     */
    public function file_put_contents($file, $contents, $mask = 0644)
    {
        if (file_exists($file)) {
            @unlink($file);
        }
        file_put_contents($file, $contents);

        if (file_exists($file)) {
            chmod($file, $mask);

            return true;
        }

        return false; // error
    }

    /**
     * Cache path
     */
    public function cache_path($type = '', $mask = 0755)
    {
        $path = ABTF_CACHE_DIR;
        if (!is_dir($path)) {
            if (!$this->mkdir($path, $mask)) {
                wp_die('Failed to write to ' . $path);
            }
        }

        switch ($type) {
            case "proxy":
                $path .= 'proxy/';
            break;
            case "http2_css":
                $path .= 'http2_css/';
            break;
        }
        if (!is_dir($path)) {
            if (!$this->mkdir($path, $mask)) {
                wp_die('Failed to write to ' . $path);
            }
        }

        return apply_filters('abtf_cache_path', $path);
    }

    /**
     * Cache URL
     */
    public function cache_dir($type = '')
    {
        $path = ABTF_CACHE_URL;
        switch ($type) {
            case "proxy":
                $path .= 'proxy/';
            break;
            case "http2_css":
                $path .= 'http2_css/';
            break;
        }

        return apply_filters('abtf_cache_dir', $path);
    }

    /**
     * Theme content path
     */
    public function theme_path($type = false, $mask = 0755)
    {
        $path = trailingslashit(get_stylesheet_directory()) . 'abovethefold/';
        if (!is_dir($path)) {
            if (!$this->mkdir($path, $mask)) {
                wp_die('Failed to write to ' . $path);
            }

            // put readme in /abovethefold/ directory
            $this->file_put_contents($path . 'readme.txt', file_get_contents(WPABTF_PATH . 'public/readme.txt'));
        }

        if ($type) {
            switch ($type) {
                case "critical-css":
                    $path .= 'css/';
                    if (!is_dir($path)) {
                        if (!$this->mkdir($path, $mask)) {
                            wp_die('Failed to write to ' . $path);
                        }
                    }
                break;
            }
        }

        return apply_filters('abtf_theme_path', $path);
    }

    /**
     * Theme content URL
     */
    public function theme_dir($cdn = '', $type = false)
    {
        if ($cdn !== '') {
            $path = trailingslashit($cdn) . trailingslashit(str_replace(trailingslashit(ABSPATH), '', get_stylesheet_directory_uri())) . 'abovethefold/';
        } else {
            $path = trailingslashit(get_stylesheet_directory_uri()) . 'abovethefold/';
        }

        if ($type) {
            switch ($type) {
                case "critical-css":
                    $path .= 'css/';
                break;
            }
        }

        return apply_filters('abtf_theme_dir', $path);
    }

    /**
     * Remote get using wp_remote_get (previously cURL)
     */
    public function remote_get($url, $args = array())
    {
        $args = array_merge(array(
            'timeout' => 60,
            'redirection' => 5,
            'sslverify' => false,

            // Chrome Generic Win10
            // @link https://techblog.willshouse.com/2012/01/03/most-common-user-agents/
            'user-agent' => 'Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/53.0.2785.116 Safari/537.36',
        ), $args);

        // Request headers
        if (!isset($args['headers']) || !is_array($args['headers'])) {
            $args['headers'] = array();
        }

        /**
         * Disable keep-alive
         */
        $args['headers'][] = "Connection: close";

        // Request
        $res = wp_remote_get($url, $args);
        if (is_array($res)) {
            return trim($res['body']);
        }

        return false; // error
    }

    /**
     * Fired during plugin activation.
     */
    public function activate()
    {

        /**
         * Set default options
         */
        $default_options = array( );

        /**
         * Critical CSS
         */
        $default_options['csseditor'] = true;

        /**
         * CSS Delivery Optimization
         */
        $default_options['cssdelivery'] = false;
        $default_options['loadcss_enhanced'] = true;
        $default_options['cssdelivery_position'] = 'header';

        /**
         * Javascript Delivery Optimization
         */
        $default_options['jsdelivery'] = false;
        $default_options['jsdelivery_position'] = 'header';
        $default_options['jsdelivery_jquery'] = true;
        $default_options['jsdelivery_async_all'] = true;

        /**
         * Web Font Optimization
         */
        $default_options['gwfo'] = false;
        $default_options['gwfo_loadmethod'] = 'inline';
        $default_options['gwfo_loadposition'] = 'header';
        $default_options['gwfo_googlefonts_auto'] = true;

        /**
         * Other
         */
        $default_options['debug'] = false;
        $default_options['adminbar'] = true;
        $default_options['clear_pagecache'] = false;

        // Store default options
        $options = get_option('abovethefold');
        if (empty($options)) {
            update_option("abovethefold", $default_options, true);
        }

        // setup cron
        $this->setup_cron();
    }

    /**
     * Fired during plugin deactivation.
     */
    public function deactivate()
    {

        // remove cron
        wp_clear_scheduled_hook('abtf_cron');
    }

    /**
     * Cron method
     */
    public function cron()
    {

        // proxy cleanup cron
        $this->proxy->cron_prune();

        // HTTP2 critical css cleanup cron
        $this->criticalcss->http2_cache_cron_prune();
    }

    /**
     * Setup cron
     */
    public function setup_cron()
    {
        if (function_exists('wp_next_scheduled') && !wp_next_scheduled('abtf_cron')) {
            //schedule the event to run twice daily
            wp_schedule_event(current_time('timestamp'), 'twicedaily', 'abtf_cron');
        }
    }
}