<?php
class Zend_Service_Digg extends Zend_Rest_Client
{
    protected $_uri = 'http://services.digg.com/';
    protected $_params = array();
    protected $_responseType = 'xml';
    protected $_responseTypes = array('php', 'xml', 'json');

    public function __construct()
    {
        $this->setUri($this->_uri);
        $client = self::getHttpClient();
        $client->setHeaders('Accept-Charset', 'ISO-8859-1,utf-8');
    }

    public function setParams($params)
    {
    	// Validate mandatory parameters to endpoint
    	if (!isset($params['appkey']) || !isset($params['appkey'])) {
            throw new Zend_Service_Digg_Exception('Param appkey missing');
        }

        foreach ($params as $key => $value) {
            switch (strtolower($key)) {
                case 'type':
                    $this->setResponseType($value);
                    break;
                default:
                    $this->_params[$key] = $value;
                    break;
            }
        }

        return $this;
    }

    public function getParams()
    {
    	return $this->_params;
    }

    public function setResponseType($responseType)
    {
        if (!in_array(strtolower($responseType), $this->_responseTypes)) {
            throw new Zend_Service_Digg_Exception('Invalid Response Type');
        }

        $this->_responseType = strtolower($responseType);
        return $this;
    }

    public function getResponseType()
    {
        return $this->_responseType;
    }

    public function sendRequest($requestType, $path)
    {
        $requestType = ucfirst(strtolower($requestType));
        if ($requestType !== 'Post' && $requestType !== 'Get') {
            throw new Zend_Service_Digg_Exception('Invalid request type: ' . $requestType);
        }

        try {
            $requestMethod = 'rest' . $requestType;
            $response = $this->{$requestMethod}($path, $this->getParams());
            return $this->formatResponse($response);
        } catch (Zend_Http_Client_Exception $e) {
            throw new Zend_Service_Digg_Exception($e->getMessage());
        }
    }

    public function formatResponse(Zend_Http_Response $reposne)
    {
        if ('json' === $this->getResponseType()) {
            return $response->getBody();
        } elseif ('php' === $this->getResponseType()) {
            return unserialize($response->getBody());
        } else {
            return new Zend_Rest_Client_Result($response->getBody());
        }
    }

    public function fetchPopularStoriesByTopic($topic, array $params = array())
    {
        $this->setParams($params);

        $path = sprintf('/stories/topic/%s/popular/', trim(strtolower($topic)));
        return $this->sendRequest('GET', $path);
    }
}