blueweather/api/json.php

<?php

/**
 * BlueWeather
 *
 * PHP version 7.2
 *
 * @param locId
 * @param range   (range[from]: from UNIX time; range[to]: to UNIX time)
 * @param maxVals (maximum measvals to be transmitted; if more are present in the timespan, the avarage will be calculated)
 *
 * @category Tools
 * @package  BlueWeather
 * @author   Dorian Zedler <dorian@itsblue.de>
 * @license  GPLV3 gpl.com
 * @link     itsblue.de
 */

require_once './config.php';



header('Content-Type: application/json');
header('Access-Control-Allow-Origin: *');

$con = mysqli_connect($config['dbhost'], $config['dbuser'], $config['dbpassword'], $config['dbname']);
if (!$con) {
    echo "<h1>Fatal internal Error! :-/</h1>";
    echo "Error connecting to database: " . mysqli_connect_error();
    http_response_code(500);
    exit();
}

if (isset($_GET['locId'])) {
    // get data of given location
    $locId = $con->real_escape_string($_GET['locId']);
    $range['from'] = $con->real_escape_string($_GET['range']['from']);
    $range['to'] = $con->real_escape_string($_GET['range']['to']);
    $maxVals = $con->real_escape_string($_GET['maxVals']);

    $sql = "SELECT * FROM `locations`
    WHERE`id`=$locId";
    $result = $con->query($sql);

    // only one row will be returned
    $data = $result->fetch_assoc();

    if (!isset($range['from']) || $range['from'] === "") {
        $range['from'] = time() - 24 * 60 * 60;
    }

    if (!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 = $con->query($sql);

    while ($row = $result->fetch_assoc()) {
        $measvalues[] = $row;
    }

    // get all sensors of given location
    $sql = "SELECT * FROM `sensors`
    WHERE `locationid` = $locId";

    $result = $con->query($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 = $con->query($sql);

    //loop through the returned data
    while ($row = $result->fetch_assoc()) {
        foreach ($sensors as $sensor) {
            if ($sensor['valuetypeid'] == $row['id']) {
                $valuetypes[] = $row;
                break;
            }
        }
    }

    if (isset($maxVals) && $maxVals > 0 && count($measvalues) > $maxVals) {
        // build the new measvalues array with respect to maxVals for each sensor

        $finalMeasvals = array();

        foreach ($sensors as $sensor) {


            $rawMeasvalsOfThisSensor = array();
            $finalMeasvalsOfThisSensor = array();

            foreach ($measvalues as $measvalue) {
                if ($measvalue["sensorid"] === $sensor["id"]) {
                    array_push($rawMeasvalsOfThisSensor, $measvalue);
                }
            }

            $countOfValuesForAvarage = intval(round(count($rawMeasvalsOfThisSensor) / $maxVals, 0));

            $takenValuesForNextSum = 0;
            $tmpMeasvalueSum = 0;
            $tmpTimestampSum = 0;

            for ($i = 0; $i < count($rawMeasvalsOfThisSensor); $i++) {
                $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;
                }
            }


            //print_r($finalMeasvalsOfThisSensor);

            $finalMeasvals = array_merge($finalMeasvals, $finalMeasvalsOfThisSensor);
        }

        $measvalues = $finalMeasvals;
    }

    // find actual range
    $min;
    $max;
    foreach ($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);
} else {
    // get all locations
    $sql = "SELECT * FROM `locations`";
    $result = $con->query($sql);

    //loop through the returned data
    while ($row = $result->fetch_assoc()) {
        $data[] = $row;
    }
}

http_response_code(200);

echo json_encode($data);