const express = require('express');
const compression = require('compression');
const util = require('util');
const fs = require('fs');
const path = require('path');
const os = require('os');

const exec = util.promisify(require('child_process').exec);
const readFileAsync = util.promisify(fs.readFile);

const app = express(); // app is an instance of express

app.use(compression()); // enables gzip compression

app.options('*', (req, res) => {
	res.set({
		'Access-Control-Allow-Origin': '*',
		'Access-Control-Allow-Methods': 'GET, OPTIONS',
		'Access-Control-Allow-Headers': 'Content-Type',
		'Access-Control-Max-Age': 600
	})
	res.status(200).end();
})

app.get('/dvbStatus', async (req, res) => {
	res.set({
		'Access-Control-Allow-Origin': '*'
	});
	const { stdout, stderr } = await exec('DTV');
	const i = parseInt(stdout) * 1e-6; // i is in Hz; divide by 1M to have MHz
	res.send({
		"id": "dvb-t-status",
		"data": `Frontend Frequency: ${i} Mhz`,
		"stderr": stderr
	});

});

app.get('/dvbChannel', async (req, res) => {
	res.set({
		'Access-Control-Allow-Origin': '*'
	});
	const { stdout, stderr } = await exec('DTV');
	const i = parseInt(stdout) * 1e-6; // i is in Hz; divide by 1M to have MHz
	readFileAsync(path.join(__dirname,"frequencies.json"))
	.then(res2 => {
		const db = JSON.parse(res2);
		res.send({
			"id": `dvb-t-channel`,
			"name": db[i]["name"].toString(),
			"data": db[i]["channels"].toString(),
			"stderr": stderr
		});
	})
	.catch(err => console.error(err))


});

app.get('/internetCheck', async (req, res) => {
	res.set({
		'Access-Control-Allow-Origin': '*'
	});
	const { stdout, stderr } = await exec('/media/hd/data/projects/icanhazip');
    res.send(
        {
            "id": "internet-check",
            "data": stdout,
            "stderr": stderr
		}
	)

});

app.get('/sysStatus', async (req, res) => {
	res.set({
		'Access-Control-Allow-Origin': '*'
	});
	readFileAsync('/sys/class/thermal/thermal_zone0/temp')
	.then(res2=>
	{	
		res.send(
			{
				"id": "sys-stats",
				"data": `Temp: ${(parseFloat(res2)*1e-3).toFixed(2)} °C Load Avg: ${os.loadavg().map(x=>x.toFixed(2)).toString()}`,
				"stderr": ""
			}
		)
	})
	.catch(err=> { 
		console.error(err)
		res.send(
			{
				"id": "sys-stats",
				"data": `Load Avg: ${os.loadavg().map(x=>x.toFixed(2)).toString()}`,
				"stderr": err
			}
		)
	})

});


app.use(express.static('/var/www/default')); // serve static build site

// app.get('*', (req, res) => {
//   res.sendFile(__dirname + '/public/index.html');
// });

//app.listen(8000,"192.168.10.14", () => console.log('listen on 8000')); 
app.listen(process.env.NODE_PORT,'127.0.0.80', () => console.log('listen on 3000'));