<?php
	class sm_api {

		private $api_url = 'https://local-api.123devis.com';
		private $api_version = "0.5";
		private $cache_mechanism = "ETAG";
		private $api_country;
		private $path = array();
		private $sm_settings;
		private $headers;
		private $more_xfer_data = array();

		public function __construct($sm_aff_id = "0", $sm_token = "not stated"){
			$this->sm_settings = array(
				'sm_aff_id' => $sm_aff_id,
				'sm_token' => $sm_token
			);

			//setup the headers to transmit sm creds
			$this->headers = array(
				"user-agent" => "Servicemagic API Lib {$this->api_version}",
				"x-sm-token" => $this->sm_settings['sm_token']
			);

			//forward the php session id and the users ip for better tracking
			$session_id = session_id();

			if (!empty($session_id)){
				$this->headers["X-SMF-FORWARDED-SESSION-ID"] = $session_id;
			}

			//more tracking data
			if (!empty($_SERVER['REMOTE_ADDR'])){
				$this->headers["X-SMF-FORWARDED-IP"] = $_SERVER['REMOTE_ADDR'];
			}

			//if (!empty($_SERVER['HTTP_USER_AGENT'])){
			//	$this->headers["X-SMF-FORWARDED-USER-AGENT"] = $_SERVER['HTTP_USER_AGENT'];
			//}

			if (!empty($_SERVER['REQUEST_URI'])){
				$this->headers["X-SMF-FORWARDED-PATH"] = $_SERVER['REQUEST_URI'];
			}

			if (!empty($_SERVER["HTTP_HOST"])){
				$this->more_xfer_data["serving_host"] = $_SERVER["HTTP_HOST"];
			}
		}

		public function get_api_version(){
			return  $this->api_version;
		}

		public function set_api_url($api_url, $api_server){
			$this->api_url = $api_url;
			$this->api_server = $api_server;
		}

		public function set_cache_mechanism($cache_mechanism){
			$this->cache_mechanism = $cache_mechanism;
		}

		public function add_xfer_data($name, $data_str){
			$this->more_xfer_data[$name] = $data_str;
		}

		public function add_header($name, $val){
			$this->headers[$name] = $val;
		}

		public function delete_header($name){
			unset($this->headers[$name]);
		}

		public function get_country(){
			return preg_replace("/^(dev-|local-)/", "", $this->api_server);
		}

		public function get($a = array()){
			return $this->call("get", $a);
		}

		public function post($a = array()){
			return $this->call("post", $a);
		}

		public function delete($a = array()){
			return $this->call("delete", $a);
		}

		//shortcut to not make http request but use template hierarchy polymorphically
		public function renderable($a = array()){
			return $this->call("renderable", $a);
		}

		private function call($mthd, $call_args){
			//init var
			$from_cache = 0;

			//merge the xtra transfer data
			$call_args = array_merge($this->more_xfer_data, $call_args);

			//save the path to here for reeuse in rendering
			$renderable_class_name = "sm_" . implode("_", $this->path);

			//if $more contains any same path references need to add to array
			$more_path = array();
			foreach ($this->path as $spath){
				$more_path[] = $spath;
				if (array_key_exists($spath, $call_args)){
					$more_path[] = $call_args[$spath];
				}
			}

			//clear the path for object reeuse
			$this->path = array();

			//can be called for renderable so that we just give back the renderable object without traumatizing all the data variables
			if ($mthd == "renderable"){
				return new $renderable_class_name($call_args, $this->sm_settings, $this);
			}

			//determine the whole url
			$url = implode("/", array_merge(array($this->api_url, $this->api_server, $this->sm_settings['sm_aff_id'], $this->api_version),  $more_path));

			// clean for local dev urls since these have the info in the subdomain
			if (false !== strpos($url, '123devis')) {
				$url = preg_replace("/(local|dev)-(uk|fr|de|it|es)\//", "", $url);
			}
			// URL locale
			if( false !== strpos($this->api_server, 'local-')) {
				$this->api_url = 'https://local-api.123devis.com';
				$url = implode("/", array_merge(array($this->api_url, $this->sm_settings['sm_aff_id'], $this->api_version),  $more_path));
			}

			switch($mthd){
				case 'get' :
					//only get requests should ever be cached
					//make a cache name that is ok relative to wp multisite potential conflicts
					$cache_identifyer_str = implode("_", $more_path) . '__' . $this->sm_settings['sm_aff_id'] . '_' . $this->get_country();

					//now that we have name, check the cache for quicker response
					$cache = new sm_cacheing();
					$cached_api_data = $cache->retrieve($cache_identifyer_str);

					if (isset($cached_api_data['etag']) and $this->cache_mechanism == 'ETAG'){
						$this->add_header('If-None-Match', $cached_api_data['etag']);
					} else {
						$this->delete_header('If-None-Match');
					}

					if ($this->cache_mechanism == 'Timeout' and !empty($cached_api_data)){
						$api_data = $cached_api_data;
						$from_cache = 1;
					} else {
						$sm_http = $this->http_factory(array( 'headers' => $this->prep_headers() ));

						//make the call
						$sm_http->get($url, $call_args);

						if ($sm_http->get_response_field('status_code') == '304'){
							$from_cache = 1;
							$api_data = $cached_api_data;
							unset($api_data['etag']);
						} else {
							$api_data_str = $sm_http->get_response_field("body");
							$api_data_str = str_replace("SMTP Error: Could not connect to SMTP host smtp-host\n", "", $api_data_str);
							$api_data = json_decode($api_data_str, 1);
						}
					}

				break;
				case 'post' :
					$sm_http = $this->http_factory(array( 'headers' => $this->prep_headers() ));
					$sm_http->post($url, $call_args);
					$api_data_str = $sm_http->get_response_field("body");
					$api_data_str = str_replace("SMTP Error: Could not connect to SMTP host smtp-host\n", "", $api_data_str);
					$api_data = json_decode($api_data_str, 1);
				break;
				default :
					throw new Exception('Invalid http method. Please use get or post.');
				break;
			}

			//do something for misformatted or empty response
			if (empty($api_data)) {
				$error_data = array(
					"from_cache" => $from_cache,
					"url"=> $url
				);
				if (isset($api_data_str)){
					$error_data["api_data_str"] = $api_data_str;
					throw new sm_exception_httperror ("data failed json decode with string : "
						. substr($api_data_str, 0, 40)
						. (strlen($api_data_str) > 40 ? "..." : "."), $error_data);
				}
				//print_r($error_data);
				throw new sm_exception_httperror ("api_data failed", $error_data);
			}

			//the api throws errors with the json key success = false (empty), do something in this case
			if (isset($api_data['success']) and $api_data['success'] === false) {
				$error_data = array(
					"from_cache" => $from_cache,
					"url"=> $url
				);
				if (isset($api_data_str)){
					$error_data["api_data_str"] = $api_data_str;
				}
				if (isset($call_args)){
					$error_data["call_args"] = $call_args;
				}

				throw new sm_exception_httperror ("api error", $error_data);
			}

			if ($mthd == "get" and !$from_cache and $sm_http->get_response_field("status_code") != "304"){
				//save etag for cacheing reeuse
				if ($etag = $sm_http->get_response_field("etag")){
					$api_data['etag'] = $etag;
				}
				$cache->save($cache_identifyer_str, $api_data);
			}
			unset($api_data['etag']);

			return new $renderable_class_name($api_data, $this->sm_settings, $this);
		}

		private function http_factory($data){
			$http_loader = new sm_http();

			$http = $http_loader->get_http_obj();

			$http->set_timeout("get", (getenv("SM_DEV") ? 20 : 4));
			$http->set_timeout("post", (getenv("SM_DEV") ? 40 : 12));

			foreach ($data['headers'] as $header){
				$http->add_http_header($header);
			}
			return $http;
		}

		private function prep_headers(){
			$headers = array();
			foreach ($this->headers as $header_key => $header_val){
				$headers[] = $header_key . ": " . $header_val;
			}
			return $headers;
		}

		//magic method used to build path url for api ex $api->account->validate->get();
		public function __get($name){
			$this->path[] = strtolower($name);
			return $this;
		}
	}