www/getfermentlog.php

<?php

require_once('config.php');

if (isset($_GET["code"]))
	$code = $_GET["code"];
else
	$code = "TB0015";

$query = "SELECT datetime,temperature_air,temperature_beer,temperature_chiller,temperature_room,target_low,target_high,heater_usage,cooler_usage FROM log_fermentation WHERE product_code='".$code."'";
$connect = mysqli_connect(DBASE_HOST,DBASE_USER,DBASE_PASS,DBASE_NAME);
if (! $connect) {
	echo "[]";
	return;
}
$step = 600; // Must be a multiple of 300
$ld = 0;
$lh = 0;
$ch = 0;
$lc = 0;
$cc = 0;
$result = mysqli_query($connect, $query);
while ($row = mysqli_fetch_array($result, MYSQLI_ASSOC)) {

	$dt = new DateTime($row['datetime'], new DateTimeZone('Europe/Amsterdam'));
	$ts = $dt->getTimestamp();
	$diff = $ts - $ld;

	if ($diff < $step) {
		// Read on
	} else if ($diff > $step) {
		// Reset, out of sync.
		$ld = $ts;
		$lh = $ch = $row['heater_usage'];
		$lc = $cc = $row['cooler_usage'];
	} else {
		// This is a valid timeframe.
		$ch = $row['heater_usage'];
		$cc = $row['cooler_usage'];
		$heat = round(($ch - $lh) / ($step / 100));
		$cool = round(($cc - $lc) / ($step / 100));
//		echo $heat . ' ' . $cool . PHP_EOL;
		$logs[] = array(
			'date' => $row['datetime'],
			'air' => $row['temperature_air'],
			'beer' => $row['temperature_beer'],
			'chiller' => $row['temperature_chiller'],
			'room' => $row['temperature_room'],
			'tlo' => $row['target_low'],
			'thi' => $row['target_high'],
			'heater' => $heat,
			'cooler' => $cool
		);
		$ld = $ts;
		$lh = $ch;
		$lc = $cc;
	}
}
echo json_encode($logs);