<?php
//-----------------------------------------CONSTANTS-------------------------------------------
//include push notification file to send a notification if necessary
include 'push-notification.php';

// Prepare variables for database connection
$dbusername = "test-minme";  // enter database username, I used "arduino" in step 2.2
$dbpassword = "Minlab2016!";  // enter database password, I used "arduinotest" in step 2.2
$server = "mysql.cae.wisc.edu"; // IMPORTANT: if you are using XAMPP enter "localhost", but if you have an online website enter its address, ie."www.yourwebsite.com"

//temperature and humidity limits that cause push notifications
$tempUpLimit = 24.5;
$tempLowLimit = 21.5;
$humidUpLimit = 70.0;
$humidLowLimit = 0.0;

//minimum number of minutes between push notifications if out of range
//seconds is needed for when times are subtracted
$minPushMinutes = 30;
$minPushSeconds = $minPushMinutes*60;
//--------------------------------------------------------------------------------------------


//current temperature and humidity in string form -- will use if push notification is sent out
$tempString = $_GET["temperature"];
$humidString = $_GET["humidity"];

//removes the unit on the end of the temperature and humidity and converts to a float
$temperature = floatval(substr($tempString, 0, -1));
$humidity = floatval(substr($humidString, 0, -1));

// Connect to your database
$dbconnect = mysql_pconnect($server, $dbusername, $dbpassword);
$dbselect = mysql_select_db($dbArduino,$dbconnect);

$sql = "INSERT INTO Arduinodata.sensor(temperature, humidity) VALUES ('".$_GET["temperature"]."', '".$_GET["humidity"]."')";

//Execute SQL statement to put new data point in database then close the connection
mysql_query($sql);

//variables out of range and last notification was longer ago than threshold
if (shouldSendNotification() == 1) {
	//message to send out with the push notification
	$message = '';

	//custom message for all possibilities
	if ($temperature >= $tempUpLimit) {
		$message = 'Temperature is too high! The current temperature is ' + $tempString;
	} else if ($temperature <= $tempLowLimit) {
		$message = 'Temperature is too low! The current temperature is ' + $tempString;
	} else if ($humidity >= $humidUpLimit) {
		$message = 'Humidity is too high! The current humidity is ' + $humidString;
	} else if ($humidity <= $humidLowLimit) {
		$message = 'Humidity is too low! The current humidity is ' + $humidString;
	}

	//construct the message to be sent based on which parameter is out of order
	sendPushNotification($message);
}
//push notification should not be sent
else {
	//don't need to do anything here for now
}

//close the database connection
mysql_close($dbconnect);






//-----------------------------------------FUNCTIONS-------------------------------------------

/**
 * Uses thresholds and time to check whether or not to send out a push notification.
 *
 * @return 1 if notification should be sent. -1 otherwise.
 */
function shouldSendPushNotification() {
	//formatted this way so it is easier to add new variables. You can make it one if statement, but it will
	//get very long as more parameters are added

	//last notification sent out was longer ago than the threshold. (specified in constants above)
	if (compareTime() == 1) {
		//variables are out of range -- return 1
		if ($temperature >= $tempUpLimit OR $temperature <= $tempLowLimit) {
			return 1;
		}
		else if ($humidity >= $humidUpLimit OR $humidity <= $humidLowLimit) {
			return 1;
		}



		//ADD MORE PARAMETERS HERE AS NEEDED WITH 'ELSE IF' STATEMENTS



		//none of the variables were out of range
		//don't send push notification -- return -1
		else {
			return -1;
		}
	}

}


/**
 * Compares the current time and the time a push notification was last sent.
 *
 * @return 1 if a push notification should be sent and returns -1 if a push notification
 * should not be sent.
 */
function compareTime() {
	//get the date/time the last push notification was sent from the database
	$dbselect = mysql_select_db($dbName, $dbconnect);

	//mySQL query to get the date of last push notification
	//gets all data (only 1 entry) from the last push date table
	$result = mysql_query("SELECT * FROM PushNotificationData.LastPushData");

	//make sure the time zone is correct
	date_default_timezone_set('America/Chicago');
	//get the current date and time
	$dateString = date('Y-m-d H:i:s');


	//check if the table is empty -- if empty just insert immediately and return 1 (send notification)
	if (mysql_num_rows($result) == 0) {
		//update the date/time of the last push notification sent to the server database
		//id will always be 1 so the date will just get overwritten each time
		$sql = "INSERT INTO PushNotificationData.LastPushData (id, date) VALUES (1, '$dateString')";
		$insertResult = mysql_query($sql);

		if ($insertResult == TRUE) {
			echo "initial new date added successfully";
		}
		//insert failed try one more time
		else {
			echo "Error when adding new date. Trying again.";
			//echo mysql_error($dbconnect);
			mysql_query($sql);
		}

		//no date in system -- send out notification
		return 1;
	}
	//there was a date in a system need to check if it was more than 30 min ago.
	else {
		$date = strtotime($dateString);

		//gets the date string from the query result
		$prevDateString = mysql_fetch_assoc($result)['date'];
		//converts the date string into a time in seconds
		$prevDate = strtotime($prevDateString);

		//check if the minutes apart is larger than the minimum limit
		if (($date-$minPushSeconds) >= $prevDate) {
			//update the date/time of the last push notification sent to the server database
			//id will always be 1 so the date will just get overwritten each time
			$sql = "UPDATE PushNotificationData.LastPushData SET date='$dateString' WHERE id=1";
			//$sql = "INSERT INTO PushNotificationData.LastPushData (id, date) VALUES (1, '$dateString') ON DUPLICATE id UPDATE date='$dateString'";
			$insertResult = mysql_query($sql);

			if ($insertResult == TRUE) {
				echo "updated new date added successfully";
			}
			//insert failed try one more time
			else {
				echo "Error when adding new date. Trying again. ";
				echo msql_error($dbconnect);
				mysql_query($sql);
			}

			//return 1 to send a push notification
			return 1;
		}
		//not enough time has passed to send another notification -- return -1
		else {
			return -1;
		}
	}

}


/**
 * Sends a push notification out to all devices with the given message
 *
 * @param message the message to send with the notification
 */
function sendPushNotification($message) {
	$push = new PushNotification();

	//get the array of device tokens with a server request
	$dbselect = mysql_select_db($dbPushNotification,$dbconnect);
	//get the tokens from its database
	$token_query = mysql_query("SELECT token FROM PushNotificationData.Tokens");

	//convert the data from the table into an array of tokens
	$tokens = array();

	//loop through all rows of tokens and make an array
	while($row = mysql_fetch_assoc($token_query)) {
		// Add each token into an array
		array_push($tokens, $row['token']);
	}

	//data for the push notification -- array of device tokens and the message
	$data = array('deviceToken' => $tokens,'message' => $message);

	//send out the push notification
	$push->Notification($data);
}

?>