<?php
/**
* BlueWeather
*
* PHP version 7.2
*
* @category Tools
* @package BlueWeather
* @author Dorian Zedler <dorian@itsblue.de>
* @license GPLV3 gpl.com
* @link itsblue.de
*/
class BlueWeather
{
private $_config;
private $_con;
/**
* Constructor
*
* @param mixed $_config config array containing some stuff
*
* @return void
*/
public function __construct($_config)
{
$this->_config = $_config;
$this->_con = mysqli_connect(
$_config['dbhost'],
$_config['dbuser'],
$_config['dbpassword'],
$_config['dbname']
);
if (!$this->_con) {
echo "Error connecting to database: " . mysqli_connect_error();
http_response_code(500);
die();
}
}
// -------------------
// - user management -
// -------------------
/**
* Function to login users
*
* @param string $username username
* @param string $password passowrd
*
* @return string '' or session token
*/
public function loginUser($username, $password)
{
$sql = "SELECT * FROM `users`
WHERE`username`=\"".$this->_con->real_escape_string($username)."\"";
$result = $this->_con->query($sql);
// only one row will be returned
$data = $result->fetch_assoc();
if (!password_verify($password, $data['password'])) {
return "";
}
//generate random token
$length = 10;
$str = "";
$characters = array_merge(range('A', 'Z'), range('a', 'z'), range('0', '9'));
$max = count($characters) - 1;
for ($i = 0; $i < $length; $i++) {
$rand = mt_rand(0, $max);
$str .= $characters[$rand];
}
$token_hash = password_hash($str, PASSWORD_DEFAULT);
$sql = 'INSERT INTO `sessions` (userId, session)
VALUES ("'. $data['id'] .'", "'. $token_hash .'")';
if (!$this->_con->query($sql)) {
return "";
}
return $token_hash;
}
/**
* Function to check if a session token exists and get the corresponding user
*
* @param string $session session token
*
* @return int (-1: does not exist; >0: userId)
*/
public function checkSession($session)
{
$sql = "SELECT * FROM `sessions`
WHERE`session`=\"".$this->_con->real_escape_string($session)."\"";
$result = $this->_con->query($sql);
if (!$result->num_rows > 0) {
return -1;
}
// only one row will be returned
$data = $result->fetch_assoc();
return($data['userId']);
}
/**
* Function to user information
*
* @param int $userId id of the user
*
* @return mixed (array with some user information, or -1 if user not found)
*/
public function getUserInfo($userId)
{
$sql = "SELECT username,realname,email FROM `users`
WHERE`id`=\"".$this->_con->real_escape_string($userId)."\"";
$result = $this->_con->query($sql);
if (!$result->num_rows > 0) {
return -1;
}
// only one row will be returned
$data = $result->fetch_assoc();
$data["emailHash"] = md5(strtolower(trim($data["email"])));
return($data);
}
/**
* Function to destroy a user session
*
* @param string $session session-token
*
* @return int 200: OK; 401: session does not exist
*/
public function destroySession($session)
{
$sql = "DELETE FROM `sessions`
WHERE `session`=\"".$this->_con->real_escape_string($session)."\"";
if ($this->_con->query($sql)) {
return 200;
} else {
return 500;
}
}
// --------------------
// - getter functions -
// --------------------
/**
* Function to get all locations from the database
*
* @return mixed (array with all locations)
*/
public function getAllLocations()
{
// get all locations
$sql = "SELECT * FROM `locations`";
$result = $this->_con->query($sql);
//loop through the returned data
while ($row = $result->fetch_assoc()) {
$locations[] = $row;
}
return $locations;
}
/**
* Function to get the data of a specific location
*
* @param int $locId id of the location to return data of
* @param mixed $range contains 'from' and 'to' as unix timestamps
* @param mixed $maxVals array containing:
* 'count': maximum measvals to be transmitted
* 'mode':
* - 'newest': will return the newest <maxVals> values
* - 'oldest': will return the oldest <maxVals> values
* - 'avg' : <maxVals> sub avarages will be calculated
*
* @return mixed object with all information about the location (see docs)
*/
function getLocationData($locId, $range, $maxVals)
{
$locId = $this->_con->real_escape_string($locId);
$range["from"] = $this->_con->real_escape_string($range["from"]);
$range["to"] = $this->_con->real_escape_string($range["to"]);
$sql = "SELECT * FROM `locations`
WHERE`id`=$locId";
$result = $this->_con->query($sql);
// only one row will be returned
$data = $result->fetch_assoc();
if (!isset($range['from']) || $range['from'] === "") {
$range['from'] = time() - 24 * 60 * 60;
}
if ($range['from'] < 0) {
$range['from'] = time() + $range['from'];
}
if (!isset($range['to']) || $range['to'] === "") {
$range['to'] = time();
}
// get all measvalues of given location
$sql = "SELECT M.measvalue,M.sensorid,M.timestamp FROM measvalues M
JOIN sensors S ON M.sensorid = S.id
JOIN locations L ON S.locationid=L.id
WHERE L.id=$locId AND M.timestamp > " . $range['from'] .
" AND M.timestamp < " . $range['to'] .
" ORDER BY timestamp ASC";
$result = $this->_con->query($sql);
while ($row = $result->fetch_assoc()) {
$measvalues[] = $row;
}
// get all sensors of given location
$sql = "SELECT * FROM `sensors`
WHERE `locationid` = $locId";
$result = $this->_con->query($sql);
//loop through the returned data
while ($row = $result->fetch_assoc()) {
unset($row['locationid']); // remove locId as it is redundant
$sensors[] = $row;
}
// get all value types
$sql = "SELECT * FROM `valuetypes`";
$result = $this->_con->query($sql);
// get all necessaray valuetypes
while ($row = $result->fetch_assoc()) {
foreach ($sensors as $sensor) {
if ($sensor['valuetypeid'] == $row['id']) {
$valuetypes[] = $row;
break;
}
}
}
if (isset($maxVals) && isset($maxVals['count']) && isset($maxVals['mode'])) {
// build the new measvalues array with respect to maxVals for each sensor
$finalMeasvals = array();
foreach ($sensors as $sensor) {
$rawMeasvalsOfThisSensor = array();
$finalMeasvalsOfThisSensor = array();
// get all measvalues of the current sensor
foreach ($measvalues as $measvalue) {
if ($measvalue["sensorid"] === $sensor["id"]) {
array_push($rawMeasvalsOfThisSensor, $measvalue);
}
}
if (count($rawMeasvalsOfThisSensor) <= $maxVals['count']) {
// measvls don't exceed maxVals -> nothng needs to be done
$finalMeasvals = array_merge(
$finalMeasvals, $rawMeasvalsOfThisSensor
);
continue;
}
switch($maxVals['mode']) {
case "newest":
$finalMeasvalsOfThisSensor = array_slice(
$rawMeasvalsOfThisSensor,
count($rawMeasvalsOfThisSensor) - $maxVals['count'],
count($rawMeasvalsOfThisSensor)
);
break;
case "oldest":
$finalMeasvalsOfThisSensor = array_slice(
$rawMeasvalsOfThisSensor, 0, $maxVals['count']
);
break;
case "avg":
// always sum up the same amount of values to get a new array
// which doesn't have more than $maxVals values
$countOfValuesForAvarage = intval(
round(count($rawMeasvalsOfThisSensor) / $maxVals['count'], 0)
);
$takenValuesForNextSum = 0;
$tmpMeasvalueSum = 0;
$tmpTimestampSum = 0;
for ($i = 0; $i < count($rawMeasvalsOfThisSensor); $i++) {
// loop through all measvals of the sensor
$measvalue = $rawMeasvalsOfThisSensor[$i];
if ($measvalue["sensorid"] === $sensor["id"]) {
$tmpMeasvalueSum += $measvalue["measvalue"];
$tmpTimestampSum += $measvalue["timestamp"];
$takenValuesForNextSum += 1;
}
if ($takenValuesForNextSum === $countOfValuesForAvarage
|| $i === count($rawMeasvalsOfThisSensor) - 1
) {
array_push(
$finalMeasvalsOfThisSensor,
array(
"measvalue" => round(
$tmpMeasvalueSum / $takenValuesForNextSum, 2
),
"timestamp" => round(
$tmpTimestampSum / $takenValuesForNextSum, 0
),
"sensorid" => $sensor["id"]
)
);
$takenValuesForNextSum = 0;
$tmpMeasvalueSum = 0;
$tmpTimestampSum = 0;
}
}
break;
}
// insert the new vals of this sensor into the global new vals
$finalMeasvals = array_merge(
$finalMeasvals, $finalMeasvalsOfThisSensor
);
}
$measvalues = $finalMeasvals;
}
// find actual range
$min = null;
$max = null;
foreach ($measvalues as $value) {
if ($value['timestamp'] < $min || !isset($min)) {
$min = $value['timestamp'];
} else if ($value['timestamp'] > $max || !isset($max)) {
$max = $value['timestamp'];
}
}
// add sensors and value types to data object
$data['measvalues'] = $measvalues;
$data['sensors'] = $sensors;
$data['valuetypes'] = $valuetypes;
$data['range'] = array('from' => $min, 'to' => $max);
return $data;
}
// --------------------
// - setter functions -
// --------------------
/**
* Function to generate an api key for specific user
*
* @param int $userId userId
*
* @return bool
*/
function createApiKey($userId)
{
//generate random token
$length = 10;
$str = "";
$characters = array_merge(range('A', 'Z'), range('a', 'z'), range('0', '9'));
$max = count($characters) - 1;
for ($i = 0; $i < $length; $i++) {
$rand = mt_rand(0, $max);
$str .= $characters[$rand];
}
$apiKey = password_hash($str, PASSWORD_DEFAULT);
$sql = "INSERT INTO `apikeys` (userid, apikey)
VALUES (\"$userId\", \"$apiKey\")";
return $this->_con->query($sql);
}
/**
* Function to validate and insert submited sensor data
*
* @param mixed $sensorData object containing
* - identity (int)
* - signature (string)
* - data (string: JSON array[array[sensorId,measvalue,timestamp]])
*
* @return array
* 'status': 200: was inserted
* 400: format of request was wrong
* 401: signture verify failed
* 404: key identity was not found
* 500: internal error
* 900: format of data JSON string was invalid
* 901: signature was fine but one or more sensors have been ignored due to some error (see 'data') all other sensors were processes successfully
* 'data': Array[Array[sensorId, errorCode]] sensors which were ignored due to some error (401: user doesn't own sensor; 404: senso wasn't found)
* only set if status is 901
*/
function processSensorData($sensorData)
{
// check if request structure is valid
if (!isset($sensorData['identity']) || !isset($sensorData['signature']) || !isset($sensorData['data'])) {
return array("status"=>400);
}
// get private key from database
$thisIdentity = $this->_con->real_escape_string($sensorData['identity']);
$thisData = $sensorData['data'];
// get public key of user
$sql = "SELECT * FROM `apikeys` WHERE id=$thisIdentity";
$result = $this->_con->query($sql);
if ($result->num_rows < 1) {
// public key was not found
return array("status"=>404);
}
// only one row will be returned
$data = $result->fetch_assoc();
$key = $data['apikey'];
$thisUserId = $data["userid"];
// check signature
$signedHash = hash_hmac("sha256", $thisData, $key);
if ($signedHash !== strtolower($sensorData['signature'])) {
return array("status"=>401);
}
// signature is valid
$measvalues = json_decode($thisData, true);
if (!$measvalues) {
// the format of the data JSON is invalid
return array("status"=>901, "data"=>"malformed data JSON");
}
$allSensors = array();
$validSensors = array();
$ignoredSensors = array();
// find all sensors
foreach ($measvalues as $measvalue) {
$thisSensorId = $this->_con->real_escape_string($measvalue[0]);
if (!in_array($thisSensorId, $allSensors)) {
array_push($allSensors, $thisSensorId);
}
}
// check if all sensors are valid and belong to the user
foreach ($allSensors as $sensor) {
// check if sensor belongs to user
$sql = "SELECT userid FROM `sensors` WHERE id=\"$sensor\"";
$result = $this->_con->query($sql);
if ($result->num_rows < 1) {
// sensor was not found
array_push($ignoredSensors, array($sensor, 404));
continue;
}
// only one row will be returned
$data = $result->fetch_assoc();
if ($data['userid'] !== $thisUserId) {
// sensor does not belong to user
array_push($ignoredSensors, array($sensor, 401));
continue;
}
array_push($validSensors, $sensor);
}
// iterate through all measvalues
// and insert them into the database if the sensor is valid
foreach ($measvalues as $measvalue) {
if (!in_array($measvalue[0], $validSensors)) {
// if the sensor is not valid -> continue
continue;
}
$thisSensorId = $this->_con->real_escape_string($measvalue[0]);
$thisMeasvalue = $this->_con->real_escape_string($measvalue[1]);
$thisTimestamp = $this->_con->real_escape_string($measvalue[2]);
$sql = "INSERT INTO `measvalues` (sensorid,measvalue,timestamp)
VALUES (\"$thisSensorId\", \"$thisMeasvalue\", \"$thisTimestamp\")";
$this->_con->query($sql);
}
if (count($ignoredSensors) > 0) {
return array("status"=>901, "data"=>$ignoredSensors);
}
return array("status"=>200);
}
// --------------------
// - Helper functions -
// --------------------
/**
* Function to convert a string to hex
*
* @param string $string the string to be converted
*
* @return string
*/
function strToHex($string)
{
$hex = '';
for ($i=0; $i<strlen($string); $i++) {
$ord = ord($string[$i]);
$hexCode = dechex($ord);
$hex .= substr('0'.$hexCode, -2);
}
return strToUpper($hex);
}
/**
* Function to convert hex to string
*
* @param string $hex hex to be converted
*
* @return string
*/
function hexToStr($hex)
{
$string='';
for ($i=0; $i < strlen($hex)-1; $i+=2) {
$string .= chr(hexdec($hex[$i].$hex[$i+1]));
}
return $string;
}
}
?>