<?php
/*
 * Copyright 2010 Google Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
require_once realpath(dirname(__FILE__) . '/../../../autoload.php');

/**
 * This class implements the RESTful transport of apiServiceRequest()'s
 *
 * @author Chris Chabot <chabotc@google.com>
 * @author Chirag Shah <chirags@google.com>
 */
class Google_Http_REST
{

    /**
     * Executes a Google_Http_Request
     *
     * @param Google_Client $client            
     * @param Google_Http_Request $req            
     * @return array decoded result
     * @throws Google_Service_Exception on server side error (ie: not authenticated,
     *         invalid or malformed post body, invalid url)
     */
    public static function execute(Google_Client $client, Google_Http_Request $req)
    {
        $httpRequest = $client->getIo()->makeRequest($req);
        $httpRequest->setExpectedClass($req->getExpectedClass());
        return self::decodeHttpResponse($httpRequest, $client);
    }

    /**
     * Decode an HTTP Response.
     *
     * @static
     *
     * @throws Google_Service_Exception
     * @param Google_Http_Request $response
     *            The http response to be decoded.
     * @param Google_Client $client            
     * @return mixed|null
     */
    public static function decodeHttpResponse($response, Google_Client $client = null)
    {
        $code = $response->getResponseHttpCode();
        $body = $response->getResponseBody();
        $decoded = null;
        if ((intVal($code)) >= 300) {
            $decoded = json_decode($body, true);
            $err = 'Error calling ' . $response->getRequestMethod() . ' ' . $response->getUrl();
            if (isset($decoded['error']) && isset($decoded['error']['message']) && isset($decoded['error']['code'])) {
                // if we're getting a json encoded error definition, use that instead of the raw response
                // body for improved readability
                $err .= ": ({$decoded['error']['code']}) {$decoded['error']['message']}";
            } else {
                $err .= ": ($code) $body";
            }
            $errors = null;
            // Specific check for APIs which don't return error details, such as Blogger.
            if (isset($decoded['error']) && isset($decoded['error']['errors'])) {
                $errors = $decoded['error']['errors'];
            }
            if ($client) {
                $client->getLogger()->error($err, array(
                    'code' => $code,
                    'errors' => $errors
                ));
            }
            throw new Google_Service_Exception($err, $code, null, $errors);
        }
        // Only attempt to decode the response, if the response code wasn't (204) 'no content'
        if ($code != '204') {
            $decoded = json_decode($body, true);
            if ($decoded === null || $decoded === "") {
                $error = "Invalid json in service response: $body";
                if ($client) {
                    $client->getLogger()->error($error);
                }
                throw new Google_Service_Exception($error);
            }
            if ($response->getExpectedClass()) {
                $class = $response->getExpectedClass();
                $decoded = new $class($decoded);
            }
        }
        return $decoded;
    }

    /**
     * Parse/expand request parameters and create a fully qualified
     * request uri.
     *
     * @static
     *
     * @param string $servicePath            
     * @param string $restPath            
     * @param array $params            
     * @return string $requestUrl
     */
    public static function createRequestUri($servicePath, $restPath, $params)
    {
        $requestUrl = $servicePath . $restPath;
        $uriTemplateVars = array();
        $queryVars = array();
        foreach ($params as $paramName => $paramSpec) {
            if ($paramSpec['type'] == 'boolean') {
                $paramSpec['value'] = ($paramSpec['value']) ? 'true' : 'false';
            }
            if ($paramSpec['location'] == 'path') {
                $uriTemplateVars[$paramName] = $paramSpec['value'];
            } else 
                if ($paramSpec['location'] == 'query') {
                    if (isset($paramSpec['repeated']) && is_array($paramSpec['value'])) {
                        foreach ($paramSpec['value'] as $value) {
                            $queryVars[] = $paramName . '=' . rawurlencode(rawurldecode($value));
                        }
                    } else {
                        $queryVars[] = $paramName . '=' . rawurlencode(rawurldecode($paramSpec['value']));
                    }
                }
        }
        if (count($uriTemplateVars)) {
            $uriTemplateParser = new Google_Utils_URITemplate();
            $requestUrl = $uriTemplateParser->parse($requestUrl, $uriTemplateVars);
        }
        if (count($queryVars)) {
            $requestUrl .= '?' . implode($queryVars, '&');
        }
        return $requestUrl;
    }
}
