class Redmine
{
    private $service_url    = 'http://meine-domain.de:3000/';
    private $key            = 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX';

    public function createIssue( redmineIssueModel $issueModel )
    {
        $issue = array('issue' => $issueModel );
        $curl_post_data = json_encode( $issue );

        $curl = curl_init( $this->service_url . 'issues.json?key=' . $this->key );
        curl_setopt( $curl, CURLOPT_RETURNTRANSFER, true );
        curl_setopt( $curl, CURLOPT_POST, true );
        curl_setopt( $curl, CURLOPT_HTTPHEADER, array( 'Content-Type: application/json') );
        curl_setopt( $curl, CURLOPT_POSTFIELDS, $curl_post_data );
        $result = $this->execute( $curl );
        return $result->issue->id;
    }
    
    /**
     * @param integer $id
     * @return models\redmineIssueModel
     * @throws Exception
     */
    public function getIssue( $id )
    {
        $curl = curl_init( $this->service_url . 'issues/' . $id . '.json?key=' . $this->key );
        curl_setopt( $curl, CURLOPT_RETURNTRANSFER, true );
        curl_setopt( $curl, CURLOPT_HTTPHEADER, array( 'Content-Type: application/json') );
        curl_setopt( $curl, CURLOPT_CUSTOMREQUEST, "GET");
        $result = $this->execute( $curl );

        if( $result === null )
        {
            return null;
        }

        $issueModel                 = new models\redmineIssueModel();
        $issueModel->subject        = $result->issue->subject;
        $issueModel->description    = $result->issue->description;
        $issueModel->done_ratio     = $result->done_ratio;
        $issueModel->assigned_to_id = $result->issue->assigned_to->id;
        $issueModel->priority_id    = $result->issue->priority->id;
        $issueModel->status_id      = $result->issue->status->id;
        $issueModel->tracker_id     = $result->issue->tracker->id;
        return $issueModel;
    }

    /**
     * @param redmineIssueModel $issueModel
     * @param integer $id
     * @return bool
     * @throws Exception
     */
    public function updateIssue( redmineIssueModel $issueModel, $id )
    {
        $issue = array('issue' => $issueModel );
        $curl_post_data = json_encode( $issue );

        $curl = curl_init( $this->service_url . 'issues/' . $id . '.json?key=' . $this->key );
        curl_setopt( $curl, CURLOPT_RETURNTRANSFER, true );
        curl_setopt( $curl, CURLOPT_CUSTOMREQUEST, "PUT");
        curl_setopt( $curl, CURLOPT_HTTPHEADER, array( 'Content-Type: application/json') );
        curl_setopt( $curl, CURLOPT_POSTFIELDS, $curl_post_data );
        $result = $this->execute( $curl );

        if( $result === '' )
        {
            return true;
        }

        return false;
    }

    /**
     * @param integer $id
     * @return bool
     * @throws Exception
     */
    public function deleteIssue( $id )
    {
        $curl = curl_init( $this->service_url . 'issues/' . $id . '.json?key=' . $this->key );
        curl_setopt( $curl, CURLOPT_RETURNTRANSFER, true );
        curl_setopt( $curl, CURLOPT_HTTPHEADER, array( 'Content-Type: application/json') );
        curl_setopt( $curl, CURLOPT_CUSTOMREQUEST, "DELETE");
        $result = $this->execute( $curl );

        if( $result === '' )
        {
            return true;
        }

        return false;
    }

    /**
     * @param  $curl
     * @return mixed
     * @throws Exception
     */
    private function execute( $curl )
    {
        $curl_response = curl_exec( $curl );

        if( $curl_response === false )
        {
            curl_close( $curl );
            throw new \Exception( 'Service Unavailable', 503 );
        }

        curl_close( $curl );
        $decoded = json_decode( $curl_response );

        if( isset( $decoded->error ) )
        {
            throw new \Exception( $decoded->error, $decoded->status );
        }

        return $decoded;
    }
}