<?php

/**
 * Sends request to API
 * @param $request - associative array to pass to API, "format" 
 * key will be overridden
 * @param $cookie - cookies string to be passed
 * @return
 * * NULL - communication to API failed
 * * ($err_code, $data) if response was OK, $data is an associative
 * array, $err_code is an error numeric code 
 */

function _smsapi_communicate($request, $cookie=NULL){
	$request['format'] = "json";
	$curl = curl_init();
	curl_setopt($curl, CURLOPT_URL, "http://api2.ssms.su/");
	curl_setopt($curl, CURLOPT_POST, True);
	curl_setopt($curl, CURLOPT_POSTFIELDS, $request);
	curl_setopt($curl, CURLOPT_RETURNTRANSFER, True);
	if(!is_null($cookie)){
		curl_setopt($curl, CURLOPT_COOKIE, $cookie);
	}
	$data = curl_exec($curl);
	curl_close($curl);
	if($data === False){
		return NULL;
	}
	$js = json_decode($data, $assoc=True);
	if(!isset($js['response'])) return NULL;
	$rs = &$js['response'];
	if(!isset($rs['msg'])) return NULL;
	$msg = &$rs['msg'];
	if(!isset($msg['err_code'])) return NULL;
	$ec = intval($msg['err_code']);
	if(!isset($rs['data'])){ $data = NULL; }else{ $data = $rs['data']; }
	return array($ec, $data);
}


/**
 * Sends a message via ssms_su api, combining authenticating and sending
 * message in one request.
 * @param $email, $passwrod - login info
 * @param $phone - recipient phone number in international format (like 7xxxyyyzzzz)
 * @param $text - message text, ASCII or UTF-8.
 * @param $params - additional parameters as key => value array, see API doc.
 * @return 
 * * NULL if API communication went a wrong way
 * * array(>0) - if an error has occurred (see API error codes)
 * * array(0, n_raw_sms, credits) - number of SMS parts in message and 
 * price for a single part
 */
function smsapi_push_msg_nologin($email, $password, $phone, $text, $params = NULL){
	$req = array(
		"method" => "push_msg",
		"api_v"=>"1.1",
		"email"=>$email,
		"password"=>$password,
		"phone"=>$phone,
		"text"=>$text);
	if(!is_null($params)){
		$req = array_merge($req, $params);
	}
	$resp = _smsapi_communicate($req);
	if(is_null($resp)){
		// Broken API request
		return NULL;
		return "";
	}
	$ec = $resp[0];
	if($ec != 0){
		return array($ec);
		return "";
	}
	if(!isset($resp[1]['n_raw_sms']) OR !isset($resp[1]['credits'])){
		return NULL; // No such fields in response while expected
		return "";
	}
	$n_raw_sms = $resp[1]['n_raw_sms'];
	$credits = $resp[1]['credits'];
	return array(0, $n_raw_sms, $credits);
	return "";
}

/**
 * Logs in API, producing a session ID to be sent back in session 
 * cookie.
 * @param $email - user's email
 * @param $password - user's password
 * @return 
 * * array(0,$cookie) - if OK, where $cookie is a string 
 * "sid=${session_id}" to be passed to cURL
 * * array(>0) - if API returned an error code (included)
 * * NULL is API communication failed
 */
function smsapi_login($email, $password){
	$req = array("method" => "login",
		"format" => "json",
		"email" => $email,
		"password" => $password);
	$ret=_smsapi_communicate($req);
	if(is_null($ret)){
		return NULL;
	}
	$ec = $ret[0];
	if($ec != 0){
		return array($ec);
	}
	if( ! isset($ret[1]['sid'])){
		return NULL;
	}
	$usid = urlencode($ret[1]['sid']);
	$cookie = "sid=$usid";
	return array(0,$cookie);
}


/**
 * Sends message via API, using previously obtained cookie to 
 * authenticate.
 * @param $cookie - string, returned by smsapi_login, "sid=..."
 * @param $phone - target phone
 * @param $text - message text, ASCII or UTF-8
 * @param params - dictionary of optional parameters, see API 
 * documentation of push_msg method
 * @return 
 * * NULL if communication to API failed
 * * array(>0) if an error occured (see API error codes)
 * * array(0, n_raw_sms, credits) - number of SMS parts in message and 
 * price for a single part
 */
function smsapi_push_msg($cookie, $phone, $text, $params = NULL){
	$req = array(
		"method" => "push_msg",
		"api_v"=>"1.1",
		"phone"=>$phone,
		"text"=>$text);
	if(!is_null($params)){
		$req = array_merge($req, $params);
	}
	$resp = _smsapi_communicate($req, $cookie);
	if(is_null($resp)){
		// Broken API request
		return NULL;
	}
	$ec = $resp[0];
	if($ec != 0){
		return array($ec);
	}
	if(!isset($resp[1]['n_raw_sms']) OR !isset($resp[1]['credits'])){
		return NULL; // No such fields in response while expected
	}
	$n_raw_sms = $resp[1]['n_raw_sms'];
	$credits = $resp[1]['credits'];
	return array(0, $n_raw_sms, $credits);
}
?>