<?php

include 'dbconnect.php';

$ip_address = "0.0.0.0";
$port = "7331";

// open a server on port 7331
$server = stream_socket_server("tcp://$ip_address:$port", $errno, $errorMessage);

if ($server === false) {
    die("stream_socket_server error: $errorMessage");
}

$client_socks = array();

while (true) {
    // prepare readable sockets
    $read_socks = $client_socks;
    $read_socks[] = $server;

    // start reading and use a large timeout
    if(!stream_select($read_socks, $write, $except, 300000)) {
        die('stream_select error.');
    }

    // new client
    if(in_array($server, $read_socks)) {
        $new_client = stream_socket_accept($server);

        if ($new_client) {
            //print remote client information, ip and port number
            echo 'new connection: ' . stream_socket_get_name($new_client, true) . "\n";

          $client_socks[] = $new_client;
            echo "total clients: ". count($client_socks) . "\n";

            // $output = "hello new client.\n";
            // fwrite($new_client, $output);
        }

        //delete the server socket from the read sockets
        unset($read_socks[ array_search($server, $read_socks) ]);
    }

    // message from existing client
    foreach ($read_socks as $sock) {
        $data = fread($sock, 128);
        
        echo "data: " . $data . "\n";

		$tk103_data = explode( ',', $data);
		$response = "";		

        switch (count($tk103_data)) {
            case 1: // 359710049095095 -> heartbeat requires "ON" response
				$response = "ON";
            break;
            case 3: // ##,imei:359710049095095,A -> this requires a "LOAD" response
				if (tk103_data[0] == "##") {
					$response = "LOAD"
				}
            break;
            case 19: // imei:359710049095095,tracker,151006012336,,F,172337.000,A,5105.9792,N,11404.9599,W,0.01,322.56,,0,0,,,  -> this is our gps data
				$imei = substr($tk103_data[0], 5);
				$alarm = $tk103_data[1];
				$gps_time = nmea_to_mysql_time($tk103_data[2]);
				$latitude = degree_to_decimal($tk103_data[8], $tk103_data[8]);				
				$latitude = degree_to_decimal($tk103_data[10], $tk103_data[11]);
				$speed_in_knots = $tk103_data[12];
				$speed_in_mph = 1.15078 * $speed_in_knots;
				$bearing = $tk103_data[13];			

				insert_location_into_db($imei, $gps_time, $latitude, $longitude, $speed_in_mph, $bearing);

				if ($alarm == "help me") {
					$response = "**,imei:" + $imei + ",E;";
				}
            break;
        }

        if (!$data) {
            unset($client_socks[ array_search($sock, $client_socks) ]);
            @fclose($sock);
            echo "client disconnected. total clients: ". count($client_socks) . "\n";
            continue;
        }

        //send the message back to client
        if (sizeof($response) > 0) {
        	fwrite($sock, $response);
	}
    }
} // end while loop

function insert_location_into_db($imei, $gps_time, $latitude, $longitude,$speed_in_mph, $bearing) {

	$params = array(':latitude'          => $latitude, 
                    ':longitude'         => $longitude,
                    ':user_name'         => "tk103-user",
                    ':phone_number'      => $imei,
                    ':session_id'        => "1",
                    ':speed'             => $speed_in_mph,
                    ':direction'         => $bearing,
                    ':distance'          => "0",
                    ':gps_time'          => $gps_time,
                    ':location_method'   => "",
                    ':accuracy'          => "0",
                    ':extra_info'        => "",
                    ':event_type'        => "tk103");

	// PLEASE NOTE, I am hardcoding the wordpress table prefix (wp_) until I can find a better way
	$stmt = $pdo->prepare('CALL wp_save_gps_location(
				:latitude, 
                :longitude, 
                :user_name,
				:phone_number,
				:session_id 
                :direction, 
                :distance, 
                :gps_time, 
                :location_method,
                :accuracy, 
                :extra_info, 
                :event_type);');
    
	$stmt->execute($params);
	$timestamp = $stmt->fetchColumn();
	echo $timestamp;
}

function nmea_to_mysql_time($date_time){
	$year = substr($date_time,0,2);
	$month = substr($date_time,2,2);
	$day = substr($date_time,4,2);
        $hour = substr($date_time,6,2);
    	$minute = substr($date_time,8,2);
    	$second = substr($date_time,10,2);
		
    	return date("Y-m-d H:i:s", mktime($hour,$minute,$second,$month,$day,$year));
}
           
function degree_to_decimal($coordinates_in_degrees, $direction){
    	$degrees = (int)($coordinates_in_degrees / 100); 
    	$minutes = $coordinates_in_degrees - ($degrees * 100);
    	$seconds = $minutes / 60;
    	$coordinates_in_decimal = $degrees + $seconds;
    		
        if (($direction == "S") || ($direction == "W")) {
        	$coordinates_in_decimal = $coordinates_in_decimal * (-1);
    	}
            
       	return number_format($coordinates_in_decimal, 6,'.','');
}