<?php
/**
 * Pimf
 *
 * @copyright Copyright (c)  Gjero Krsteski (http://krsteski.de)
 * @license   http://krsteski.de/new-bsd-license New BSD License
 */
namespace Pimf;

use Pimf\Util\String as Str;

/**
 * URL
 *
 * <code>
 *    // create a URL to a location within the application
 *    $url = Url::to('user/profile');
 *
 *    // create a HTTPS URL to a location within the application
 *    $url = Url::to('user/profile', true);
 * </code>
 *
 * @package Pimf
 * @author  Gjero Krsteski <gjero@krsteski.de>
 */
class Url
{
  /**
   * The cached base URL.
   *
   * @var string
   */
  public static $base;

  /**
   * Get the full URI including the query string.
   *
   * @return string
   */
  public static function full()
  {
    return static::to(Uri::full());
  }

  /**
   * Get the full URL for the current request.
   *
   * @return string
   */
  public static function current()
  {
    return static::to(Uri::current(), null, false);
  }

  /**
   * Get the URL for the application root.
   *
   * @param null|bool $https
   *
   * @return string
   */
  public static function home($https = null)
  {
    return static::to('/', $https);
  }

  /**
   * Get the base URL of the application.
   *
   * @return string
   */
  public static function base()
  {
    if (isset(static::$base)) {
      return static::$base;
    }

    $conf = Registry::get('conf');
    $url  = $conf['app']['url'];

    if ($url !== '') {
      $base = $url;
    } else {
      $base = Registry::get('env')->getUrl();
    }

    return static::$base = $base;
  }

  /**
   * Generate an application URL.
   *
   * @param string    $url
   * @param null|bool $https
   * @param bool      $asset
   *
   * @return string
   */
  public static function to($url = '', $https = null, $asset = false)
  {
    $url = trim($url, '/');

    if (static::valid($url)) {
      return $url;
    }

    $root = self::format($https, $asset);

    return rtrim($root, '/') . '/' . ltrim($url, '/');
  }

  /**
   * Computes the URl method
   *
   * @param null|bool $https
   * @param bool      $asset
   *
   * @return string
   */
  private static function format($https = null, $asset = false)
  {
    $root = static::base();
    $conf = Registry::get('conf');

    if (!$asset) {
      $root .= '/' . $conf['app']['index'];
    }

    // Unless $https is specified we set https for all secure links.
    if (is_null($https)) {
      $https = Registry::get('env')->isHttps();
    }

    // disable SSL on all framework generated links to make it more
    // convenient to work with the site while developing locally.
    if ($https and $conf['ssl']) {
      return preg_replace('~http://~', 'https://', $root, 1);
    }

    return preg_replace('~https://~', 'http://', $root, 1);
  }

  /**
   * Generate an application URL with HTTPS.
   *
   * @param string $url
   *
   * @return string
   */
  public static function as_https($url = '')
  {
    return static::to($url, true);
  }

  /**
   * Generate an application URL to an asset.
   *
   * @param  string $url
   * @param  bool   $https
   *
   * @return string
   */
  public static function to_asset($url, $https = null)
  {
    if (static::valid($url) or static::valid('http:' . $url)) {
      return $url;
    }

    $conf = Registry::get('conf');
    $root = ($conf['app']['asset_url'] != '') ? $conf['app']['asset_url'] : false;

    // shoot us through a different server or third-party content delivery network.
    if ($root) {
      return rtrim($root, '/') . '/' . ltrim($url, '/');
    }

    $url = static::to($url, $https, true);

    // we do not need to come through the front controller.
    if ($conf['app']['index'] !== '') {
      $url = str_replace($conf['app']['index'] . '/', '', $url);
    }

    return $url;
  }

  /**
   * Determine if the given URL is valid.
   *
   * @param  string $url
   *
   * @return bool
   */
  public static function valid($url)
  {
    if (Str::startsWith($url, '//')) {
      return true;
    }

    return filter_var($url, FILTER_VALIDATE_URL) !== false;
  }

  /**
   * Get cleaner URLs or old-fashioned » RFC 3986 URL-query string.
   *
   * @param string $route controller/action
   * @param array  $params
   * @param null   $https
   * @param bool   $asset
   *
   * @return string
   */
  public static function compute($route = '', array $params = array(), $https = null, $asset = false)
  {
    // if your application should work with RFC 3986 URL-query strings
    $conf = Registry::get('conf');
    if ($conf['app']['routeable'] === false) {
      list($controller, $action) = explode('/', $route);
      $params = array_merge(compact('controller', 'action'), $params);

      return Str::ensureTrailing('/', self::format($https, $asset)) . '?' . http_build_query($params, null, '&');
    }

    // otherwise PIMF will serve you cleaner URLs
    $slug = implode('/', $params);
    if ($slug != '') {
      $slug = '/' . $slug;
    }

    return self::to($route, $https, $asset) . $slug;
  }
}