#!/usr/bin/env php
<?php

use Mosquitto\Client;
use Mosquitto\Message;

define("MQTT_HOST", getenv("MQTT_HOST"));
define("ENERGY_METER_TOPIC", getenv("ENERGY_METER_TOPIC"));
define("DOOR_TOPIC", getenv("DOOR_TOPIC"));
define("ENERGY_PRICE", floatval(getenv("ENERGY_PRICE")));
define("OUTPUT_TOPIC_PREFIX", getenv("OUTPUT_TOPIC_PREFIX"));


echo "using configuration:\n";
echo "  MQTT_HOST: " . MQTT_HOST . "\n";
echo "  ENERGY_METER_TOPIC: " . ENERGY_METER_TOPIC . "\n";
echo "  DOOR_TOPIC: " . DOOR_TOPIC . "\n";
echo "  ENERGY_PRICE: " . ENERGY_PRICE . "\n";
echo "  OUTPUT_TOPIC_PREFIX: " . OUTPUT_TOPIC_PREFIX . "\n";



$doorStatus = null;
$energyCounter = null;
$doorOpenEnergy = null;
$doorOpenTime = null;
$lastOutput = 0;

$c = new Client();

if (getenv("MQTT_USER") && getenv("MQTT_PASS")) {
    echo "using credentials\n";
    echo "  MQTT_USER: " . getenv("MQTT_USER") . "\n";
    echo "  MQTT_PASS: " . str_repeat("*", strlen(getenv("MQTT_PASS"))) . "\n";

    $c->setCredentials(getenv("MQTT_USER"), getenv("MQTT_PASS"));
}

$c->connect(MQTT_HOST, 1883, 60);
$c->subscribe(ENERGY_METER_TOPIC, 2);
$c->subscribe(DOOR_TOPIC, 2);

$c->onMessage(function (Message $message) {
    switch ($message->topic) {
        case ENERGY_METER_TOPIC:
            energy($message->payload);
            break;
        case DOOR_TOPIC:
            door($message->payload);
            break;
    }
});

while (true) {
    while ($lastOutput > time() - 10) {
        $c->loop(1000);
    }
    output();
}

function door($newStatus)
{
    global $doorStatus, $energyCounter, $doorOpenEnergy, $doorOpenTime;
    if (is_null($energyCounter)) {
        return;
    }
    $newStatus = (bool) $newStatus;
    if ($newStatus === $doorStatus) {
        return;
    }
    $doorStatus = $newStatus;
    if (!$newStatus) {
        $doorOpenEnergy = $energyCounter;
        $doorOpenTime = time();
    }
    output();
}
function energy($value)
{
    global $energyCounter;
    $energyCounter = (float) $value;
    output();
}

function output()
{
    global $doorStatus,
        $energyCounter,
        $doorOpenEnergy,
        $doorOpenTime,
        $lastOutput,
        $c;
    if ($doorStatus) {
        $myUsage = $energyCounter - $doorOpenEnergy;
        $myCost = $myUsage * ENERGY_PRICE;
        $c->publish(
            OUTPUT_TOPIC_PREFIX . "/used_energy_float",
            strval($myUsage),
            2
        );
        $c->publish(OUTPUT_TOPIC_PREFIX . "/price_float", strval($myCost), 2);
        $c->publish(
            OUTPUT_TOPIC_PREFIX . "/price_string",
            number_format($myCost, 2, ",", "."),
            2
        );
    } else {
        $c->publish(OUTPUT_TOPIC_PREFIX . "/used_energy_float", "", 2);
        $c->publish(OUTPUT_TOPIC_PREFIX . "/price_float", "", 2);
        $c->publish(OUTPUT_TOPIC_PREFIX . "/price_string", "", 2);
    }
    $lastOutput = time();
}