<?php
# Copyright (c) 2013-2014, OVH SAS.
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/**
 * This file contains code about \Ovh\Api class
 */

namespace Ovh;

use GuzzleHttp\Client as GClient;
use GuzzleHttp\Stream\Stream;

/**
 * Wrapper to manage login and exchanges with simpliest Ovh API
 *
 * This class manage how works connections to the simple Ovh API with
 * login method and call wrapper
 * Http connections use guzzle http client api and result of request are
 * object from this http wrapper
 *
 * @package Ovh
 * @category Ovh
 * @author Vincent Cassé <vincent.casse@ovh.net>
 */
class Api
{

    /**
     * Url to communicate with Ovh API
     */
    private $endpoints = array(
        'ovh-eu' => 'https://api.ovh.com/1.0',
        'ovh-ca' => 'https://ca.api.ovh.com/1.0',
        'runabove-ca' => 'https://api.runabove.com/1.0');

    /**
     * Contain endpoint selected to choose API
     */
    private $endpoint = null;

    /**
     * Contain key of the current application
     */
    private $application_key = null;

    /**
     * Contain secret of the current application
     */
    private $application_secret = null;

    /**
     * Contain consumer key of the current application
     */
    private $consumer_key = null;

    /**
     * Contain delta between local timestamp and api server timestamp
     */
    private $time_delta = null;

    /**
     * Contain http client connection
     */
    private $http_client = null;

    /**
     * Construct a new wrapper instance
     *
     * @param $application_key key of your application.
     * For OVH APIs, you can create a application's credentials on https://api.ovh.com/createApp/
     * @param $application_secret secret of your application.
     * @param $api_endpoint name of api selected
     * @param $consumer_key If you have already a consumer key, this parameter prevent to do a
     * new authentication
     * @param $http_client instance of http client
     *
     * @throws InvalidParameterException if one parameter is missing or with bad value
     */
    public function __construct(
        $application_key,
        $application_secret,
        $api_endpoint,
        $consumer_key = null,
        GClient $http_client = null
    ) {
        if (!isset($application_key)) {
            throw new Exceptions\InvalidParameterException("Application key parameter is empty");
        }

        if (!isset($application_secret)) {
            throw new Exceptions\InvalidParameterException("Application secret parameter is empty");
        }

        if (!isset($api_endpoint)) {
            throw new Exceptions\InvalidParameterException("Endpoint parameter is empty");
        }

        if (!array_key_exists($api_endpoint, $this->endpoints)) {
            throw new Exceptions\InvalidParameterException("Unknown provided endpoint");
        }

        if (!isset($http_client)) {
            $http_client = new GClient();
        }

        $this->application_key = $application_key;
        $this->endpoint = $this->endpoints[$api_endpoint];
        $this->application_secret = $application_secret;
        $this->http_client = $http_client;
        $this->consumer_key = $consumer_key;
        $this->time_delta = null;
    }

    /**
     * Calculate time delta between local machine and API's server
     *
     * @throws \GuzzleHttp\Exception\ClientException if http request is an error
     */
    private function calculateTimeDelta()
    {
        if (!isset($this->time_delta)) {
            $response = $this->http_client->get($this->endpoint . "/auth/time");
            $serverTimestamp = (int) (String) $response->getBody();
            $this->time_delta = $serverTimestamp - (int) \time();
        }
        return $this->time_delta;
    }

    /**
     * Request a consumer key from the API and the validation link to
     * authorize user to validate this consumer key
     *
     * @param $accessRules list of rules your application need.
     * @param $redirection url to redirect on your website after authentication
     *
     * @throws \GuzzleHttp\Exception\ClientException if http request is an error
     */
    public function requestCredentials(
        $accessRules,
        $redirection = null
    ) {
        $parameters = new \StdClass();
        $parameters->accessRules = $accessRules;
        $parameters->redirection = $redirection;

        //bypass authentication for this call
        $response = $this->rawCall(
            'POST',
            '/auth/credential',
            $parameters,
            false
        );

        $this->consumer_key = $response["consumerKey"];
        return $response;
    }

    /**
     * This is the main method of this wrapper. It will
     * sign a given query and return its result.
     *
     * @param $method HTTP method of request (GET,POST,PUT,DELETE)
     * @param $path relative url of API request
     * @param $content body of the request
     * @param $is_authenticated if the request use authentication
     *
     * @throws \GuzzleHttp\Exception\ClientException if http request is an error
     */
    private function rawCall(
        $method,
        $path,
        $content = null,
        $is_authenticated = true
    ) {
        $url = $this->endpoint . $path;

        $request = $this->http_client->createRequest(
            $method,
            $url
        );

        if (isset($content) && $method == 'GET') {
            $query = $request->getQuery();
            foreach ($content as $key => $value) {
                $query->set($key, $value);
            }
            $url .= '?'.$query;
            $body = "";
        } elseif (isset($content)) {
            $body = json_encode($content);
            $request->setBody(Stream::factory($body));
        } else {
            $body = "";
        }

        $request->setHeader('Content-Type', 'application/json; charset=utf-8');
        $request->setHeader('X-Ovh-Application', $this->application_key);

        if ($is_authenticated) {
            if (!isset($this->time_delta)) {
                $this->calculateTimeDelta();
            }
            $now = time() + $this->time_delta;

            $request->setHeader('X-Ovh-Timestamp', $now);

            if (isset($this->consumer_key)) {
                $toSign =  $this->application_secret.'+'.$this->consumer_key.'+'.$method.'+'.$url.'+'.$body.'+'.$now;
                $signature = '$1$' . sha1($toSign);
                $request->setHeader('X-Ovh-Consumer', $this->consumer_key);
                $request->setHeader('X-Ovh-Signature', $signature);
            }
        }
        return $this->http_client->send($request)->json();
    }

    /**
     * Wrap call to Ovh APIs for GET requests
     *
     * @param $path path ask inside api
     * @param $content content to send inside body of request
     *
     * @throws \GuzzleHttp\Exception\ClientException if http request is an error
     */
    public function get(
        $path,
        $content = null
    ) {
        return $this->rawCall("GET", $path, $content);
    }

    /**
     * Wrap call to Ovh APIs for POST requests
     *
     * @param $path path ask inside api
     * @param $content content to send inside body of request
     *
     * @throws \GuzzleHttp\Exception\ClientException if http request is an error
     */
    public function post(
        $path,
        $content
    ) {
        return $this->rawCall("POST", $path, $content);
    }

    /**
     * Wrap call to Ovh APIs for PUT requests
     *
     * @param $path path ask inside api
     * @param $content content to send inside body of request
     *
     * @throws \GuzzleHttp\Exception\ClientException if http request is an error
     */
    public function put(
        $path,
        $content
    ) {
        return $this->rawCall("PUT", $path, $content);
    }

    /**
     * Wrap call to Ovh APIs for DELETE requests
     *
     * @param $path path ask inside api
     * @param $content content to send inside body of request
     *
     * @throws \GuzzleHttp\Exception\ClientException if http request is an error
     */
    public function delete(
        $path,
        $content = null
    ) {
        return $this->rawCall("DELETE", $path, $content);
    }

    /**
     * Get the current consumer key
     */
    public function getConsumerKey()
    {
        return $this->consumer_key;
    }

    /**
     * Return instance of http client
     */
    public function getHttpClient()
    {
        return $this->http_client;
    }
}