<?php

use Kirby\Component;
use Kirby\Pipe;
use Kirby\Registry;
use Kirby\Request;
use Kirby\Roots;
use Kirby\Urls;

class Kirby {

  static public $version = '2.3.0';
  static public $instance;
  static public $hooks = array();
  static public $triggered = array();

  public $roots;
  public $urls;
  public $cache;
  public $path;
  public $options = array();
  public $routes;
  public $router;
  public $route;
  public $site;
  public $page;
  public $plugins;
  public $response;
  public $request;
  public $components = [];
  public $registry;

  static public function instance($class = null) {
    if(!is_null(static::$instance)) return static::$instance;
    return static::$instance = $class ? new $class : new static;
  }

  static public function version() {
    return static::$version;
  }

  public function __construct($options = array()) {
    $this->roots    = new Roots(dirname(__DIR__));
    $this->urls     = new Urls();
    $this->registry = new Registry($this);
    $this->options  = array_merge($this->defaults(), $options);
    $this->path     = implode('/', (array)url::fragments(detect::path()));

    // make sure the instance is stored / overwritten
    static::$instance = $this;
  }

  public function defaults() {

    $defaults = array(
      'url'                             => false,
      'timezone'                        => 'UTC',
      'license'                         => null,
      'rewrite'                         => true,
      'error'                           => 'error',
      'home'                            => 'home',
      'locale'                          => 'en_US.UTF8',
      'routes'                          => array(),
      'headers'                         => array(),
      'languages'                       => array(),
      'roles'                           => array(),
      'cache'                           => false,
      'debug'                           => 'env',
      'ssl'                             => false,
      'cache.driver'                    => 'file',
      'cache.options'                   => array(),
      'cache.ignore'                    => array(),
      'cache.autoupdate'                => true,
      'date.handler'                    => 'date',
      'kirbytext.video.class'           => 'video',
      'kirbytext.video.width'           => false,
      'kirbytext.video.height'          => false,
      'kirbytext.video.youtube.options' => array(),
      'kirbytext.video.vimeo.options'   => array(),
      'kirbytext.image.figure'          => true,
      'content.file.extension'          => 'txt',
      'content.file.ignore'             => array(),
      'content.file.normalize'          => false,
      'email.service'                   => 'mail',
      'email.to'                        => null,
      'email.replyTo'                   => null,
      'email.subject'                   => null,
      'email.body'                      => null,
      'email.options'                   => array(),
    );

    return $defaults;

  }

  public function roots() {
    return $this->roots;
  }

  public function urls() {
    return $this->urls;
  }

  public function registry() {
    return $this->registry;
  }

  public function url() {
    return $this->urls->index();
  }

  public function options() {
    return $this->options;
  }

  public function option($key, $default = null) {
    return a::get($this->options, $key, $default);
  }

  public function path() {
    return $this->path;
  }

  public function page() {
    return $this->page;
  }

  public function response() {
    return $this->response;
  }

  /**
   * Install a new entry in the registry
   */
  public function set() {
    return call_user_func_array([$this->registry, 'set'], func_get_args());
  }

  /**
   * Retrieve an entry from the registry
   */
  public function get() {
    return call_user_func_array([$this->registry, 'get'], func_get_args());
  }

  public function configure() {

    // load all available config files
    $root    = $this->roots()->config();
    $configs = array(
      'main' => 'config.php',
      'host' => 'config.' . server::get('SERVER_NAME') . '.php',
      'addr' => 'config.' . server::get('SERVER_ADDR') . '.php',
    );

    $allowed = array_filter(dir::read($root), function($file) {
      return substr($file, 0, 7) === 'config.' and substr($file, -4) === '.php';
    });

    foreach($configs as $config) {
      $file = $root . DS . $config;
      if(in_array($config, $allowed, true) and file_exists($file)) include_once($file);
    } 

    // apply the options
    $this->options = array_merge($this->options, c::$data);

    // overwrite the autodetected url
    if($this->options['url']) {
      $this->urls->index = $this->options['url'];
    }

    // connect the url class with its handlers
    url::$home = $this->urls()->index();
    url::$to   = $this->option('url.to', function($url = '', $lang = null) {

      if(url::isAbsolute($url)) return $url;

      $start = substr($url, 0, 1);
      switch($start) {
        case '#':
          return $url;
          break;
        case '.':
          return page()->url() . '/' . $url;
          break;
        default:                            
          if($page = page($url)) {
            // use the "official" page url
            return $page->url($lang);
          } else {
            // don't convert absolute urls
            return url::makeAbsolute($url);
          }
          break;
      }

    });

    // setup the pagination redirect to the error page
    pagination::$defaults['redirect'] = $this->option('error');

    // setting up the email class
    email::$defaults['service'] = $this->option('email.service');
    email::$defaults['from']    = $this->option('email.from');
    email::$defaults['to']      = $this->option('email.to');
    email::$defaults['replyTo'] = $this->option('email.replyTo');
    email::$defaults['subject'] = $this->option('email.subject');
    email::$defaults['body']    = $this->option('email.body');
    email::$defaults['options'] = $this->option('email.options');

    // simple error handling
    if($this->options['debug'] === true) {
      error_reporting(E_ALL);
      ini_set('display_errors', 1);
    } else if($this->options['debug'] === false) {
      error_reporting(0);
      ini_set('display_errors', 0);
    }

  }

  /**
   * Registers all routes
   *
   * @param array $routes New routes
   * @return array
   */
  public function routes($routes = array()) {

    // extend the existing routes
    if(!empty($routes) and is_array($routes)) {
      return $this->options['routes'] = array_merge($this->options['routes'], $routes);
    }

    $routes = $this->options['routes'];
    $kirby  = $this;
    $site   = $this->site();

    if($site->multilang()) {

      foreach($site->languages() as $lang) {

        $routes[] = array(
          'pattern' => ltrim($lang->url . '/(:all?)', '/'),
          'method'  => 'ALL',
          'lang'    => $lang,
          'action'  => function($path = null) use($kirby, $site) {
            return $site->visit($path, $kirby->route->lang->code());
          }
        );

      }

      // fallback for the homepage
      $routes[] = array(
        'pattern' => '/',
        'method'  => 'ALL',
        'action'  => function() use($kirby, $site) {

          // check if the language detector is activated
          if($kirby->option('language.detect')) {

            if(s::get('language') and $language = $kirby->site()->sessionLanguage()) {
              // $language is already set but the user wants to 
              // select the default language
              $referer = r::referer();
              if(!empty($referer) && str::startsWith($referer, $this->urls()->index())) {
                $language = $kirby->site()->defaultLanguage();
              } 
            } else {
              // detect the user language
              $language = $kirby->site()->detectedLanguage();
            }

          } else {
            // always use the default language if the detector is disabled
            $language = $kirby->site()->defaultLanguage();
          }

          // redirect to the language homepage if necessary
          if($language->url != '/' and $language->url != '') {
            go($language->url());
          }

          // plain home pages
          return $site->visit('/', $language->code());

        }
      );

    }

    // tinyurl handling
    $routes['tinyurl'] = $this->component('tinyurl')->route();

    // home redirect
    $routes['homeRedirect'] = array(
      'pattern' => $this->options['home'],
      'action'  => function() {
        redirect::send(page('home')->url(), 307);
      }
    );

    // plugin assets
    $routes['pluginAssets'] = array(
      'pattern' => 'assets/plugins/(:any)/(:all)',
      'method'  => 'GET',
      'action'  => function($plugin, $path) use($kirby) {
        $root = $kirby->roots()->plugins() . DS . $plugin . DS . 'assets' . DS . $path;
        $file = new Media($root);

        if($file->exists()) {
          return new Response(f::read($root), f::extension($root));
        } else {          
          return new Response('The file could not be found', f::extension($path), 404);
        }


      }
    );

    // all other urls
    $routes['others'] = array(
      'pattern' => '(:all)',
      'method'  => 'ALL',
      'action'  => function($path = null) use($site, $kirby) {

        // visit the currently active page
        $page = $site->visit($path);

        // react on errors for invalid URLs
        if($page->isErrorPage() and $page->uri() != $path) {

          // get the filename
          $filename = rawurldecode(basename($path));
          $pagepath = dirname($path);

          // check if there's a page for the parent path
          if($page = $site->find($pagepath)) {
            // check if there's a file for the last element of the path
            if($file = $page->file($filename)) {
              go($file->url());
            }
          }

          // return the error page if there's no such page
          return $site->errorPage();

        }

        return $page;

      }

    );

    return $routes;

  }

  /**
   * Loads all available plugins for the site
   *
   * @return array
   */
  public function plugins() {

    // check for a cached plugins array
    if(!is_null($this->plugins)) return $this->plugins;

    // get the plugins root
    $root = $this->roots->plugins();

    // start the plugin registry
    $this->plugins = array();

    // check for an existing plugins dir
    if(!is_dir($root)) return $this->plugins;

    foreach(array_diff(scandir($root), array('.', '..')) as $file) {
      if(is_dir($root . DS . $file)) {
        $this->plugin($file, 'dir');
      } else if(f::extension($file) == 'php') {
        $this->plugin(f::name($file), 'file');
      }
    }

    return $this->plugins;

  }

  /**
   * Loads a single plugin
   *
   * @param string $name
   * @param string $mode
   * @return mixed
   */
  public function plugin($name, $mode = 'dir') {

    if(isset($this->plugins[$name])) return $this->plugins[$name];

    if($mode == 'dir') {
      $file = $this->roots->plugins() . DS . $name . DS . $name . '.php';
    } else {
      $file = $this->roots->plugins() . DS . $name . '.php';
    }

    // make the kirby variable available in plugin files
    $kirby = $this;

    if(file_exists($file)) return $this->plugins[$name] = include_once($file);

    return false;
  
  }

  /**
   * Load all default extensions
   */
  public function extensions() {

    // load all kirby tags and field methods
    include_once(__DIR__ . DS . 'extensions' . DS . 'tags.php');
    include_once(__DIR__ . DS . 'extensions' . DS . 'methods.php');

    // install additional kirby tags
    kirbytext::install($this->roots->tags());

  }

  /**
   * Autoloads all page models
   */
  public function models() {

    if(!is_dir($this->roots()->models())) return false;

    $root  = $this->roots()->models();
    $files = dir::read($root);
    $load  = array();

    foreach($files as $file) {
      if(f::extension($file) != 'php') continue;
      $name      = f::name($file);
      $classname = str_replace(array('.', '-', '_'), '', $name . 'page');
      $load[$classname] = $root . DS . $file;

      // register the model
      page::$models[$name] = $classname;
    }

    // start the autoloader
    if(!empty($load)) {
      load($load);
    }

  }

  public function localize() {

    $site = $this->site();

    if($site->multilang() and !$site->language()) {
      $site->language = $site->languages()->findDefault();
    }    

    // set the local for the specific language
    if(is_array($site->locale())) {
      foreach($site->locale() as $key => $value) {
        setlocale($key, $value);        
      }
    } else {
      setlocale(LC_ALL, $site->locale());
    }

    // additional language variables for multilang sites
    if($site->multilang()) {
      // path for the language file
      $file = $this->roots()->languages() . DS . $site->language()->code() . '.php';
      // load the file if it exists
      if(file_exists($file)) include_once($file);
    }

  }

  /**
   * Returns the branch file
   *
   * @return string
   */
  public function branch() {

    // which branch?
    $branch = count($this->options['languages']) > 0 ? 'multilang' : 'default';

    // build the path for the branch file
    return __DIR__ . DS . 'branches' . DS . $branch . '.php';

  }

  /**
   * Initializes and returns the site object
   * depending on the appropriate branch
   *
   * @return Site
   */
  public function site() {

    // check for a cached version of the site object
    if(!is_null($this->site)) return $this->site;

    // load all options
    $this->configure();

    // setup the cache
    $this->cache();

    // load the main branch file
    include_once($this->branch());

    // create the site object
    return $this->site = new Site($this);

  }

  /**
   * Cache setup
   *
   * @return Cache
   */
  public function cache() {

    if(!is_null($this->cache)) return $this->cache;

    // cache setup
    if($this->options['cache']) {
      if($this->options['cache.driver'] == 'file' and empty($this->options['cache.options'])) {
        $this->options['cache.options'] = array(
          'root' => $this->roots()->cache()
        );
      }
      return $this->cache = cache::setup($this->options['cache.driver'], $this->options['cache.options']);
    } else {
      return $this->cache = cache::setup('mock');
    }

  }

  /**
   * Renders the HTML for the page or fetches it from the cache
   *
   * @param Page $page
   * @param boolean $headers
   * @return string
   */
  public function render(Page $page, $data = array(), $headers = true) {

    // register the currently rendered page
    $this->page = $page;

    // send all headers for the page
    if($headers) $page->headers();

    // configure pagination urls
    $query  = (string)$this->request()->query();
    $params = (string)$this->request()->params() . r($query, '?') . $query;

    pagination::$defaults['url'] = $page->url() . r($params, '/') . $params;

    // cache the result if possible
    if($this->options['cache'] and $page->isCachable()) {

      // try to read the cache by cid (cache id)
      $cacheId = md5(url::current());

      // check for modified content within the content folder
      // and auto-expire the page cache in such a case
      if($this->options['cache.autoupdate'] and $this->cache()->exists($cacheId)) {

        // get the creation date of the cache file
        $created = $this->cache()->created($cacheId);

        // make sure to kill the cache if the site has been modified
        if($this->site->wasModifiedAfter($created)) {
          $this->cache()->remove($cacheId);
        }

      }

      // try to fetch the template from cache
      $template = $this->cache()->get($cacheId);

      // fetch fresh content if the cache is empty
      if(empty($template)) {
        $template = $this->template($page, $data);
        // store the result for the next round
        $this->cache()->set($cacheId, $template);
      }

      return $template;

    }

    // return a fresh template
    return $this->template($page, $data);

  }

  /**
   * Template configuration
   *
   * @param Page $page
   * @param array $data
   * @return string
   */
  public function template(Page $page, $data = array()) {
    return $this->component('template')->render($page, $data);
  }

  public function request() {
    if(!is_null($this->request)) return $this->request;
    return $this->request = new Request($this);
  }

  public function router() {
    return $this->router;
  }

  public function route() {
    return $this->route;
  }

  /**
   * Starts the router, renders the page and returns the response
   *
   * @return mixed
   */
  public function launch() {

    // this will trigger the configuration
    $site = $this->site();

    // force secure connections if enabled
    if($this->option('ssl') and !r::secure()) {
      // rebuild the current url with https
      go(url::build(array('scheme' => 'https')));
    }

    // set the timezone for all date functions
    date_default_timezone_set($this->options['timezone']);

    // load all extensions
    $this->extensions();

    // load all plugins
    $this->plugins();

    // load all models
    $this->models();

    // start the router
    $this->router = new Router($this->routes());
    $this->route  = $this->router->run($this->path());

    // check for a valid route
    if(is_null($this->route)) {
      header::status('500');
      header::type('json');
      die(json_encode(array(
        'status'  => 'error',
        'message' => 'Invalid route or request method'
      )));
    }

    // call the router action with all arguments from the pattern
    $response = call($this->route->action(), $this->route->arguments());

    // load all language variables
    // this can only be loaded once the router action has been called
    // otherwise the current language is not yet available
    $this->localize();

    // build the response
    $this->response = $this->component('response')->make($response);

    // store the current language in the session
    if($this->site()->multilang() && $language = $this->site()->language()) {
      s::set('language', $language->code());
    }

    return $this->response;

  }

  /**
   * Register a new hook
   * 
   * @param string $hook The name of the hook
   * @param closure $callback
   */
  public function hook($hook, $callback) {

    if(isset(static::$hooks[$hook]) and is_array(static::$hooks[$hook])) {
      static::$hooks[$hook][] = $callback;
    } else {
      static::$hooks[$hook] = array($callback);
    }

  }

  /**
   * Trigger a hook
   * 
   * @param string $hook The name of the hook
   * @param mixed $args Additional arguments for the hook
   * @return mixed
   */
  public function trigger($hook, $args = null) {

    if(isset(static::$hooks[$hook]) and is_array(static::$hooks[$hook])) {
      foreach(static::$hooks[$hook] as $key => $callback) {

        if(array_key_exists($hook, static::$triggered) && in_array($key, static::$triggered[$hook])) continue;

        static::$triggered[$hook] = $key;

        try {
          call($callback, $args);        
        } catch(Exception $e) {
          // caught callback error
        }
      }
    }
  }

  static public function start() {
    return kirby()->launch();
  }

  /**
   * Register and fetch core components
   */
  public function component($name, $component = null) {
    if(is_null($component)) {
      if(!isset($this->components[$name])) {
        // load the default component if it exists
        if(file_exists(__DIR__ . DS . 'kirby' . DS . 'component' . DS . strtolower($name) . '.php')) {
          $this->component($name, 'Kirby\\Component\\' . $name);
        } else {
          throw new Exception('The component "' . $name . '" does not exist');          
        }
      }
      return $this->components[$name];
    } else {

      if(!is_string($component)) {
        throw new Exception('Please provide a valid component name');
      }

      // init the component
      $object = new $component($this);

      if(!is_a($object, 'Kirby\\Component')) {
        throw new Exception('The component "' . $name . '" must be an instance of the Kirby\\Component class');
      }

      if(!is_a($object, 'Kirby\\Component\\' . $name)) {
        throw new Exception('The component "' . $name . '" must be an instance of the Kirby\\Component\\' . ucfirst($name) . ' class');
      }

      // add the component defaults
      $this->options = array_merge($object->defaults(), $this->options);

      // configure the component
      $object->configure();

      // register the component
      $this->components[$name] = $object;       

    }
  }

}