<?php
class GraphicsContext {
  protected $palette = array();
}

/**
 * A wrapper for XML elements.
 */
class Element {
  public $name = NULL;
  public $attributes = array();
  public $value = NULL;
  public $new_line; // Add a new line after element

  public function __construct($name, $attr = NULL, $value = NULL) {
    $this->name = $name;
    $this->attributes = $attr;
    $this->value = $value;
  }

  public function __toString() {
    $ret = '<'. $this->name;
    if (!empty($this->attributes)) {
      $ret .= ' ' . implode(' ', $this->attributes);
    }
    if (empty($this->value)) {
      $ret .= ' />';
    }
    else {
      $ret .= '>';
      if ($this->value instanceof Element) {
        $ret .= (string) $this->value; // force __toString()
      }
      elseif (is_array($this->value)) {
        $ret .= implode('', $this->value);
      }
      else {
        $ret .= $this->value;
      }
      $ret .= "</$this->name>";
    }
    return $ret;
  }
}

class Context {
  /**
   * Directory in which the current script is located.
   *
   * Follow symlinks if applicable, to obtain the actual implementation
   * directory, instead of just the main file symlink, in order to find the
   * other files.
   *
   * @var string
   */
  protected $dirname;

  /**
   * Requested path: <$PHP_SELF>?q=a/b/c
   *
   * @var string
   */
  protected $path = NULL;

  /**
   * Graphics context
   *
   * @var GraphicsContext
   */
  protected $gc = NULL;

  public function getDirname() {
    if (!isset($this->dirname)) {
      $this->dirname = dirname(__FILE__);
    }

    return $this->dirname;
  }

  /**
   * Return the requested path.
   *
   * @param string $path
   */
  public function getPath() {
    if (!isset($this->path)) {
      $this->path = empty($_GET['q']) ? '' : $_GET['q'];
    }

    return $this->path;
  }

  /**
   * User information: logged or not ?
   *
   * @var boolean
   */
  protected $user = FALSE;


  function __construct() {
    $this->getPath();
  }

  function __toString() {
    $ret = '<pre>' . print_r($this, TRUE) . '</pre>';
    return $ret;
  }
}

class Page extends Element {
  /**
   * @var Context
   */
  protected $context;

  /**
   * @var array
   */
  protected $styles;

  /**
   * @var array
   */
  protected $finalized = array();

  public function getHeader($name) {
  }

  public function setHeader($name, $value) {

  }

  public function getHead() {
    $this->finalizeHead();
    $head = new Element('head', NULL, $this->head);
    $ret = (string) $head;
    return $ret;
  }

  public function setHead($item) {

  }

  public function getBody() {
    $this->finalizeBody();
    $body = new Element('body', NULL, $this->body);
    $ret = (string) $body;
    return $ret;
  }

  public function setBody($fragment) {
    $this->body[] = $fragment;
  }

  public function finalizeHead() {
    if (isset($this->finalized['head'])) {
      throw new Exception('Attempt to finalize already finalized head');
    }
    $cssLink = new Element('link', array(
      'rel' => 'stylesheet',
      'type' => 'text/css',
      'href' => $this->context->getPath() .'/memcache_ui.css',
    ));
    $this->setHead($cssLink);

    $this->finalized['head'] = TRUE;
  }

  public function finalizeBody() {
    if (isset($this->finalized['body'])) {
      throw new Exception('Attempt to finalize already finalized body');
    }
    $this->finalized['body'] = TRUE;
  }

  public function render() {
    $html = new Element('html', NULL, $this->getHead() . $this->getBody());
    return (string) $html;
  }

  /**
   * Page constructor.
   *
   * @param Context $context
   * @param array $item
   *   A router info array.
   *
   * @see Router::getInfo()
   */
  public function __construct(Context $context, array $item) {
    parent::__construct('html');
    $this->context = $context;
  }
}

class Router {
  function getInfo() {
    $ret = array(
      '^server/(\w+)/flush/(\w+)$' => array(
        'page class' => 'page_server_flush',
        'page arguments' => array('$1', '$2'),
        'title callback' => 'title_server',
        'title arguments' => 'page arguments',
      ),
      '^server/(\w+)/flush$' => array(
        'page class' => 'page_server_flush',
        'page arguments' => array('$1'),
        'title callback' => 'title_server',
        'title arguments' => 'page arguments',
      ),

      '^server/(\w+)/slab/(\d+)$' => array(
        'page class' => 'page_slab_view',
        'page arguments' => array('$1', '$2'),
        'title callback' => 'title_slab',
        'title arguments' => 'page arguments',
      ),

      '^server/(\w+)/key/(.+)/delete/(\w+)$' => array(
        'page class' => 'page_variable_delete_confirm',
        'page arguments' => array('$1', '$2', '$3'),
        'title callback' => 'title_variable',
        'title arguments' => 'page arguments',
      ),
      '^server/(\w+)/key/(.+)/delete$' => array(
        'page class' => 'page_variable_delete_form',
        'page arguments' => array('$1', '$2'),
        'title callback' => 'title_variable',
        'title arguments' => 'page arguments',
      ),

      '^server/(\w+)/key/(.+)/dump$' => array(
        'page class' => 'page_variable_view_php',
        'page arguments' => array('$1', '$2'),
        'title callback' => 'title_variable',
        'title arguments' => 'page arguments',
      ),
      '^server/(\w+)/key/(.+)/php$' => array(
        'page class' => 'page_variable_view_php',
        'page arguments' => array('$1', '$2'),
        'title callback' => 'title_variable',
        'title arguments' => 'page arguments',
      ),
      '^server/(\w+)/key/(.+)$' => array(
        'page class' => 'page_variable_view_text',
        'page arguments' => array('$1', '$2'),
        'title callback' => 'title_variable',
        'title arguments' => 'page arguments',
      ),

      '^slabs$' => array(
        'page class' => 'page_slab_overview',
        'title' => 'Slabs per server',
      ),

      '^$' => array(
        'page class' => 'Page_Main',
        'title' => 'Overview',
      ),
    );

    return $ret;
  }

  function getRoute() {
    $found = FALSE;
    $path = $this->context->getPath();
    // echo "<pre>Path: [". $path . "]</p>";
    $matches = array();
    foreach ($this->getInfo() as $regex => $info) {
      $regex = "@$regex@";
      $count = preg_match($regex, $path, $matches);
      // echo "<pre>$regex: $count";
      // if ($count) print_r($matches);
      // echo "</pre>";
      if ($count) {
        $found = TRUE;
        break;
      }
    }
    if ($found) {
      // echo "Found at $regex<pre>";
      // print_r($info);
      $regexes = array_fill(0, count($info['page arguments']), $regex);
      $paths = array_fill(0, count($info['page arguments']), $path);
      $info['page arguments'] = preg_replace($regexes, $info['page arguments'], $paths);
    }
    else {
      $info = NULL;
    }

    return $info;
  }

  function __construct(Context $context) {
    $this->context = $context;
  }
}

class Page_Main extends Page {
  function finalizeBody() {
    $hello = new Element('p', NULL, 'Hello world');
    $this->setBody($hello);
    parent::finalizeBody();
  }

}

function main() {
  $context = new Context();
  // echo "<p>Dirname: [". $context->getDirname() . "]</p>";
  // echo "<p>Path: [". $context->getPath() . "]</p><pre>";

  $router = new Router($context);
  $item = $router->getRoute();
  $page = new $item['page class']($context, $item);
  // echo '<pre>'; var_dump($page);
  echo $page->render();
}

try {
  main();
}
catch (Exception $e) {
  echo '<pre>';
  echo $e->getMessage() . PHP_EOL;
  echo $e->getTraceAsString();
  echo "</pre>";
}