teasense/index.js

/*
 temperato.py - Driver of querying service
 Copyright (C) 2021,2022  William R. Moore <william@nerderium.com>

 This program is free software; you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation; either version 3 of the License, or
 (at your option) any later version.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License along
 with this program.  If not, see <https://www.gnu.org/licenses/>.
*/

import 'dotenv/config';
import fetch from 'node-fetch';
import Koa from 'koa';
import Router from '@koa/router';

const PORT = process.env.PORT || 3000;
const SET_POINT = parseFloat(process.env.SET_POINT);
const USERNAME = process.env.USERNAME;
const PASSWORD = process.env.PASSWORD;
const NOTIF_URL = process.env.NOTIF_URL;
const MESSAGE = process.env.MESSAGE;
const SENSOR_URL = process.env.SENSOR_URL;
const SLEEP_TIMER = 1000;

const app = new Koa();
const router = new Router();

router.get('/', async ctx => {
   try {
       ctx.body = `{"temperature": ${currentSensorReading}}`;
   } catch (e) {
       ctx.body = 'There was an error retrieving the sensor data.';
       ctx.status = 500;
   }
});

app
    .use(router.routes())
    .use(router.allowedMethods());

app.listen(PORT);

let currentSensorReading=0.0

async function temperatoTick() {
    try {
        const sensor = await fetch(SENSOR_URL);
        const reading = await sensor.json();
        currentSensorReading = reading.temperature;
        if (reading.temperature >= SET_POINT) {
            const basicAuth = Buffer.from(`${USERNAME}:${PASSWORD}`).toString('base64');
            await fetch(NOTIF_URL, {
                method: 'post',
                body: `{"message": "${MESSAGE}"}`,
                headers: { 'Content-Type': 'application/json', 'Authorization': `Basic ${basicAuth}` },
            });
        }
    } catch (e) {
        console.error(e);
    }
}

setInterval(() => temperatoTick(), SLEEP_TIMER);