<?php
define('_DEBUG',                    1);
define('GCALENDER_SERVICE_VERSION', '0.1');
define('MY_USER_AGENT',             'zuzara-gcalender_service-' . GCALENDER_SERVICE_VERSION);

define('CONTENT_TYPE_ATOM',         'application/atom+xml');

/**
 *  Google Calender API
 *
 *
 *  @since      2006.9.2
 *  @author     Nob Funaki <nob.funaki@gmail.com>
 */
class GCalender_Service
{
    /**
     *
     */
    var $_clientLoginUrl = 'https://www.google.com/accounts/ClientLogin';

    /**
     *
     */
    var $_feedUrlFormat = 'http://www.google.com/calendar/feeds/%s/private/full/';

    /**
     *
     */
    var $_authOptions = array(
              'Email'   => '',
              'Passwd'  => '',
              'source'  => MY_USER_AGENT,
              'service' => 'cl',
            );

    /**
     *  @param  string
     *  @param  string
     *  @return void
     */
    function GCalender_Service($email, $passwd)
    {
        if ($email != '' && $passwd != '') {
            $this->_authOptions['Email']  = $email;
            $this->_authOptions['Passwd'] = $passwd;
        } else {
            // ###
        }
    }

    /**
     *  @todo   日付による指定、25件以上になったときの対処
     */
    function get($email = '')
    {
        $url = $this->_getFeedUrl($email);
        $res = $this->_getHttpContent($url, 'GET', array(), $this->_buildGoogleLoginHeader($this->_getAuthToken()));
        return $this->_parseEntry($res);
    }

    /**
     *
     *  @param  array
     *  @return bool
     */
    function add($data)
    {
        $strEntry = $this->_buildEntry($data);
        $googlelogin = $this->_buildGoogleLoginHeader($this->_getAuthToken());
        $url = $this->_getFeedUrl();
        $buf = $this->_getHttpContent($url, 'POST', $strEntry, $googlelogin, CONTENT_TYPE_ATOM);
        $res = $this->_getHttpContent($this->_getRedirectUrl($buf), 'POST', $strEntry, $googlelogin, CONTENT_TYPE_ATOM);
        if (strpos($res, 'HTTP/1.1 201 Created') === 0) {
            return true;
        } else {
            return false;
        }
    }

    /**
     *
     */
    function update()
    {
    }

    /**
     *
     */
    function delete()
    {
    }

    /**
     *  @return mixed
     */
    function _getAuthToken()
    {
        $res = $this->_getHttpContent($this->_clientLoginUrl, 'POST', $this->_authOptions);
        if (preg_match("'Auth=(.*)'", $res, $match)) {
            return $match[1];
        } else {
            return false;
        }
    }

    /**
     *
     */
    function _getHttpContent($url, $method, $post_data = array(), $header = '', $post_contenttype = 'application/x-www-form-urlencoded', $connection = 'close')
    {
        $pUrl = parse_url($url);

        if (isset($pUrl['query'])) {
            $pUrl['query'] = '?' . $pUrl['query'];
            if (substr($pUrl['query'], -1, 1) == '_') {
                $pUrl['query'] = str_replace('_', '', $pUrl['query']); // ### GoogleCalendarのバグ？アンダーバーが含まれる場合が
            }
        } else {
            $pUrl['query'] = '';
        }
        $pUrl['port'] = $pUrl['scheme'] == 'https' ? 443 : 80;

        $request  = $method . ' ' . $pUrl['path'] . $pUrl['query'] . " HTTP/1.1\r\n";

        $request .= 'Host: ' . $pUrl['host'] . "\r\n";
        $request .= 'User-Agent: '.MY_USER_AGENT."\r\n";
        $request .= $header;
        $request .= 'Connection: '."$connection\r\n";

        switch ($method) {
            case 'POST':
            case 'PUT':
                $str = '';
                if (is_array($post_data)) {
                    foreach ($post_data as $key => $val) {
                        $str .= $key . '=' . urlencode($val) . '&';
                    }
                } else {
                    $str = $post_data;
                }
                $request .= "Content-Type: $post_contenttype\r\n";
                $request .= "Content-Length: ".strlen($str)."\r\n";
                $request .= "\r\n";
                $request .= $str;
                break;
            default:
                $request .= "\r\n";
                break;
        }

        $host = $pUrl['scheme'] == 'https' ? 'ssl://' . $pUrl['host'] : $pUrl['host'];

        $fp = fsockopen($host, $pUrl['port']);

        if (!$fp) {
            die("ERROR\n"); // ###
        }

        $this->_debug_print("\$request: $request");
        fwrite($fp, $request);

        $response = '';
        while (!feof($fp)) {
            $buf = fgets($fp);
            $response .= $buf;
        }

        fclose($fp);

        return $response;
    }

    /**
     *  Parse atom feed
     *
     *  @param  string
     *  @return array
     */
    function _parseEntry($buf)
    {
        $reg = "'<entry><id>.*?/([a-z0-9]+?)</id>.*?<title .*?>(.*?)</title><content .*?>(.*?)</content>.*?<link rel=\'edit\'.*? href=\'.*?/(\d+)\'>.*?<gd:where valueString=\'(.*?)\'>.*?<gd:when startTime=\'(\d{4})-(\d{2})-(\d{2})T.*?\'.*?</entry>'";
        $c = preg_match_all($reg, $buf, $match);
        $data = array();
        for ($i = 0; $i < $c; $i++) {
            $t = mktime(0, 0, 0, $match[7][$i], $match[8][$i], $match[6][$i]);
            $data[] = array('id' => $match[1][$i], 'title' => $match[2][$i], 'content' => $match[3][$i], 'editid' => $match[4][$i], 'where' => $match[5][$i], 'timestamp' => $t);
        }
        return $data;
    }

    /**
     *
     */
    function _getFeedUrl($email = '')
    {
        $email = ($email == '') ? $this->_authOptions['Email'] : $email;
        $email = urlencode($email);
        return sprintf($this->_feedUrlFormat, $email);
    }

    /**
     *
     */
    function _getRedirectUrl($buf)
    {
        if (preg_match("'Location: (.*)'", $buf, $match)) {
            return $match[1];
        } else {
            return false;
        }
    }

    /**
     *
     */
    function _buildGoogleLoginHeader($authToken)
    {
        return 'Authorization: GoogleLogin auth=' . $authToken . "\r\n";
    }

    /**
     *
     */
    function _buildEntry()
    {
    }

    /**
     *
     */
    function _debug_print($str)
    {
        if (defined('_DEBUG')) {
            echo $str . "\n";
        }
    }
}