<?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_sockets = array();

while (true) {
    // prepare readable sockets
    $read_sockets = $client_sockets;
    $read_sockets[] = $server;

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

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

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

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

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

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

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

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

        switch (count($tk103_data)) {
            case 1: // 359710049095095 -> heartbeat requires "ON" response
                $response = "ON";
                echo "sent ON to client\n";
                break;
            case 3: // ##,imei:359710049095095,A -> this requires a "LOAD" response
                if ($tk103_data[0] == "##") {
                    $response = "LOAD";
                    echo "sent LOAD to client\n";
                }
                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[7], $tk103_data[8]);				
                $longitude = degree_to_decimal($tk103_data[9], $tk103_data[10]);
                $speed_in_knots = $tk103_data[11];
                $speed_in_mph = 1.15078 * $speed_in_knots;
                $bearing = $tk103_data[12];			

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

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

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

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

function insert_location_into_db($pdo, $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, 
                :speed,
                :direction, 
                :distance, 
                :gps_time, 
                :location_method,
                :accuracy, 
                :extra_info, 
                :event_type);');

    $stmt->execute($params);
    $timestamp = $stmt->fetchColumn();
    // echo "inserted into db: " . $timestamp . "\n";
}

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,'.','');
}