ShortLinkPhp

<?php
/**
 * Google Apps Short Links API Class
 *
 * PHP version 5
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 *
 * @package   ShortLink
 * @author    Adrien Gibrat <adrien.gibrat@gmail.com>
 * @copyright 2011 Adrien Gibrat
 * @license   http://www.opensource.org/licenses/mit-license.php The MIT License
 * @version   1.0.0
 * @see       https://www.google.com/enterprise/marketplace/viewListing?productListingId=5143210+6352879591152674960
 * @see       http://www.google.com/support/a/bin/answer.py?answer=114245
 * @usage
    $s = new ShortLink( 'my.domain.com', 'MyHmacSecretKey','user@any-domain.com' );
    echo 'create public short url : ', $r = clone $s->pub( 'http://www.google.com' ), '<br/>', // clone result to keep it for later
        'get status : ',              $r->status, '<br/>',
        'request status : ',          $s->info( $r->short )->status, '<br/>', // non sense, only for demo purpose
        'remaining API call : ',      $s->remain, '<br/>',
        'Info request : ',            $s->request, '<br/>',
        'Creation request : ',        $r->request;
 *
 * If 'status' property is 'no response', check your domain.
 * If 'status' property is 'error 403', check your Hmac secret key or your server time setting!
 */

/**
 * Google Apps Short Links Class
 *
 * Easy usage of Google Apps Short Links API (by Google Labs)
 * 3 main methods : short, hash & info
 * + 2 convenience methods : pub & priv
 *
 * @package   ShortLink
 * @author    Adrien Gibrat <adrien.gibrat@gmail.com>
 * @copyright 2011 Adrien Gibrat
 * @license   http://www.opensource.org/licenses/mit-license.php The MIT License
 * @version   1.0.0
 *
 * Access magic properties
 *
 * @property string    $status   Status of last request
 * @property string    $long     Long link
 * @property string    $short    Short link
 * @property boolean   $public   Is link public
 * @property boolean   $hash     Is link hashed
 * @property string    $owner    Owner email
 * @property integer   $usage    Usage link counter
 * @property integer   $count    Usage link counter
 * @property integer   $remain   Remaining API call
 * @property string    $request  Requested url
 * @property stdObject $response Raw decoded response
 *
 */
class ShortLink {

    /**
     * Alias for easy access to response propeties
     * @var    array
     * @access public
     * @static
     */
  static public $alias = array(
    'usage'  => 'usage_count',
    'count'  => 'usage_count',
    'short'  => 'shortcut',
    'long'   => 'url',
    'public' => 'is_public',
    'hash'   => 'is_hash'
  );

    /**
     * Remaining API call stored by domain
     * @var    array
     * @access protected
     * @static
     */
  static protected $remain = array();

    /**
     * Max number of retry in case of creation / update failure
     * @var    integer
     * @access public
     */
  public $maxRetry = 2;

    /**
     * Actual number of retry for last request
     * @var    integer
     * @access protected
     */
  protected $retry;

    /**
     * Domain name
     * @var    string
     * @access protected
     */
  protected $domain;

    /**
     * Hmac secret key
     * @var    string
     * @access protected
     */
  protected $key;

    /**
     * User email
     * @var    string
     * @access protected
     */
  protected $user;

    /**
     * Last request url
     * @var    string
     * @access protected
     */
  protected $request;

    /**
     * Last request response
     * @var    object|false
     * @access protected
     */
  protected $response;

    /**
     * Constructor
     *
     * Set mandatory informations
     *
     * @param  string  $domain   Domain name
     * @param  string  $key      Hmac secret key
     * @param  string  $user     Owner / user email
     */
  public function __construct ( $domain, $key, $user ) {
    $this->user   = $user;
    $this->key    = $key;
    $this->domain = $domain;
  }

    /**
     * Magic getter
     *
     * Get last request, response and number of retry (read only)
     * Easy access to last response properties (with alias)
     *
     * @param  string  $property Property name
     * @return mixed             Last response property value or last request / response
     */
  public function __get ( $property ) {
    switch ( $property ) {
      case 'remain' :
        return isset( self::$remain[$this->domain] ) ? self::$remain[$this->domain] : true;
      case 'response' :
        return $this->response;
      case 'request' :
        return $this->request;
      case 'retry' :
        return $this->retry;
    }
    if ( ! $this->response ) {
        return;
    }
    $alias = isset( self::$alias[$property] ) ? self::$alias[$property] : false;
    if ( $alias && isset( $this->response->{$alias} ) ) {
      return $this->response->{$alias};
    }
    if ( isset( $this->response->{$property} ) ) {
      return $this->response->{$property};
    }
  }

    /**
     * Magic toString
     *
     * Get last response short url
     *
     * @return string            Last request short url or empty string on failure
     */
  public function __toString () {
      return $this->_success () && isset( $this->response->shortcut ) ?
        'http://' . $this->domain . '/' . $this->response->shortcut :
        '';
  }

    /**
     * Create private short link (for convenience)
     *
     * Create / update private shortcut or hashed link
     * If hashed link exists, visibility is set to private, no new hashed link is created
     * If shortcut exists, url is updated and visibility set to private
     *
     * @param  string $url       Long url to shorten
     * @param  string $shortcut  Optional shortcut, if ommited create or update hashed link
     * @return ShortLink         Chainable object to allow easy access to response
     */
  public function priv ( $url, $shortcut = null ) {
    return $shortcut ?
      $this->short( $shortcut, $url, false ) :
      $this->hash( $url, false  );
  }

    /**
     * Create public short link (for convenience)
     *
     * Create / update public shortcut or hashed link
     * If hashed link exists, visibility is set to public, no new hashed link is created
     * If shortcut exists, url is updated and visibility set to public
     *
     * @param  string $url       Long url to shorten
     * @param  string $shortcut  Optional shortcut, if ommited create or update hashed link
     * @return ShortLink         Chainable object to allow easy access to response
     */
  public function pub ( $url, $shortcut = null ) {
    return $shortcut ?
      $this->short( $shortcut, $url, true ) :
      $this->hash( $url, true );
  }

    /**
     * Create shortcut link
     *
     * Create / update shortcut link
     * If shortcut exists, url and visibility are updated
     *
     * @param  string  $shortcut Shortcut
     * @param  string  $url      Long url to shorten
     * @param  boolean $public   Short link visiblity: true = public, false = private (default)
     * @return ShortLink         Chainable object to allow easy access to response
     */
  public function short ( $shortcut, $url, $public = false ) {
    $this->_valid( $shortcut ) && $this->_request( 'get_or_create_shortlink', array(
        'is_public' => $public ? 'true' : 'false',
        'shortcut' => $shortcut,
        'url' => $url,
        'user' => $this->user
      ), $this->maxRetry );
    return $this;
  }

    /**
     * Create hashed link
     *
     * Create / update hashed link
     * If hashed link exists, visibility is updated, no new hashed link is created
     *
     * @param  string  $url      Long url to shorten
     * @param  boolean $public   Short link visiblity: true = public, false = private (default)
     * @return ShortLink         Chainable object to allow easy access to response
     */
  public function hash ( $url, $public = false ) {
    $this->_request( 'get_or_create_hash', array(
      'is_public' => $public ? 'true' : 'false',
      'url' => $url,
      'user' => $this->user
    ), $this->maxRetry );
    return $this;
  }

    /**
     * Get details about short link
     *
     * Retrieve basic informations about short link
     *
     * @param  string  $shortcut Shortcut
     * @return ShortLink         Chainable object to allow easy access to response
     */
  public function info ( $shortcut ) {
    $this->_valid( $shortcut ) && $this->_request( 'get_details', array( 'shortcut' => $shortcut ) );
    return $this;
  }

   /**
     * Send signed request to API
     *
     * Build signed GET request and get response
     * Automatically retry on failure, you can set the number of retry with public "retry" property
     *
     * @param  string  $method   Method to call
     * @param  array   $params   Request parameters
     * @param  integer $maxRetry Maximum retry
     * @return stdObject|boolean Response object on success or false on failure
     */
  protected function _request ( $method, array $params, $maxRetry = 0 ) {
    $params = array(
      'oauth_signature_method' => 'HMAC-SHA1',
      'timestamp' => time(),
      'user' => $this->user
    ) + $params;
    ksort($params);
    $params = http_build_query( $params );
    $url = 'http://' . $this->domain . '/js/' . $method;
    $signature = 'GET&' . $this->_encode( $url ) . '&' . $this->_encode( $params );
    $oauth = $this->_encode( base64_encode( hash_hmac( 'sha1', $signature, $this->key, true ) ) );
    $handle = curl_init( $this->request = $url . '?' . $params . '&oauth_signature=' . $oauth ) ;
    curl_setopt( $handle, CURLOPT_RETURNTRANSFER, 1 );
    $this->retry = 0;
    while ( ( $this->retry <= $maxRetry ) && $this->_response( $handle ) ) {
      if ( ! isset( $this->response->shortcut ) ) {
        $this->retry++;
        continue;
      }
      break;
    }
    curl_close( $handle );
    return $this->response;
  }

    /**
     * Check and set response
     *
     * Set response property on success and set appropriate status on error
     *
     * @param  ressource $curl   Curl handle ressource.
     * @return boolean           True on success or false on failure
     */
  protected function _response ( $curl ) {
    $this->response = json_decode( curl_exec( $curl ) );
    if ( $this->response && isset( $this->response->status ) ) {
      if ( isset( $this->response->estimated_api_calls_remaining ) ) {
        self::$remain[$this->domain] = $this->response->estimated_api_calls_remaining;
      }
          return true;
      }
      $code = curl_getinfo( $curl, CURLINFO_HTTP_CODE );
      $this->response = (object) array( 'status' =>  $code ? 'error ' . $code : 'no response' );
      return false;
  }

    /**
     * Proper url encode
     *
     * Replace space characters encoded as "+" by "%20"
     *
     * @param  string  $value    String to encode
     * @return string            Url-encoded string
     */
  protected function _encode ( $value ) {
    return str_replace( '+', '%20', urlencode( $value ) );
  }

    /**
     * Check shortcut
     *
     * Check if shortcut is valid, as some url specific characters are not allowed
     * Reset request and response properties if invalid shortcut (consistency purpose)
     *
     * @param  string  $shortcut Shortcut
     * @return boolean           True if shortcut is valid or false if it's not
     */
  protected function _valid ( $shortcut ) {
    if ( preg_match( '~\/|\?|=|#~', $shortcut ) ) {
      $this->retry = 0;
      $this->request = null;
      return $this->response = false;
    }
    return true;
  }

    /**
     * Check response
     *
     * Check if last response status is ok
     *
     * @return boolean           True if last response status is ok or false if it's not
     */
  protected function _success () {
    return $this->response && $this->response->status === 'ok';
  }

}
/* Bonus functions */
function utm ( $url, $campaign, $medium, $source, $content = null, $term = null ) {
    $params = array_filter( array(
      'utm_campaign' => $campaign,
      'utm_medium'   => $medium,
      'utm_source'   => $source,
      'utm_content'  => $content,
      'utm_term'     => $term
    ) );
    if ( $query = parse_url( $url, PHP_URL_QUERY ) ) {
      parse_str( $query, $oldParams );
      $params = array_merge( $oldParams, $params );
    }
    $newQuery = http_build_query( $params );
    return $query ?
      str_replace( $query, $newQuery, $url ) :
      $url . '?' . $newQuery;
}

function qr ( $url, $size = 150 ) {
  return 'http://chart.apis.google.com/chart?cht=qr&chs=' . $size . 'x' . $size . '&choe=UTF-8&chld=H&chl=' . urlencode( $url );
}