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 http = require("http");
const ping = require('ping');

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': '*'
        });
        let tuner = 0;
        tuner = req.query.t;
        const { stdout, stderr } = await exec(`DTV2 -t ${tuner}`);
        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': '*'
        });
        let tuner = 0;
        tuner = req.query.t;
        const { stdout, stderr } = await exec(`DTV2 -t ${tuner}`);
        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': '*'
        });
        http.get('http://icanhazip.com', (httpRes) => {
                httpRes.setEncoding('utf8');
                httpRes.on('data', (body) => {
                        res.send(
                                {
                                        "id": "internet-check",
                                        "data": body,
                                        "stderr": ""
                                }
                        )
                });
        });

});
app.get('/vpnCheck', async (req, res) => {
        res.set({
                'Access-Control-Allow-Origin': '*'
        });
        let ifaces = os.networkInterfaces()
        if(ifaces.hasOwnProperty('tun0')){
                res.send(
                        {
                                "id": "vpn-check",
                                "data": ifaces["tun0"][0]["cidr"],
                                "stderr": ""
                        })
        } else {
                res.send(
                        {
                                "id": "vpn-check",
                                "data": "Not connected",
                                "stderr": ""
                        })

        }

});

app.get('/sysStatus', (req, res) => {
        res.set({
                'Access-Control-Allow-Origin': '*'
        });
        readFileAsync('/sys/class/thermal/thermal_zone0/temp')
                .then(res2=>
                        {
                                res.send({
                                        "id": "sys-stats",
                                        "data": `${(parseFloat(res2)*1e-3).toFixed(2)} °C Load: ${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.get('/lancianoCheck', async (req, res) => {
        res.set({
                'Access-Control-Allow-Origin': '*'
        });
        let hostRes='';
        let hosts = ["10.8.0.45","10.8.0.46"];
        let promArr=[];
        for(let host of hosts) {
                promArr.push(ping.promise.probe(host));
        }
        Promise.all(promArr)
                .then(function (res) {
                        for (let item of res) {
                                if(item.alive) {
                                        hostRes+=item.host+' alive ';
                                }
                                else{
                                        hostRes+=item.host+' dead ';
                                }
                        }
                })
                .finally(()=>{
                        res.send({
                                "id": "lanciano-check",
                                "data": hostRes.toString(),
                                "stderr": ""
                        })
                })
})

app.use(express.static('/var/www/forbidden-fruit-dashboard')); // 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,process.env.NODE_IP, () => console.log(`Bind on ${process.env.NODE_IP}:${process.env.NODE_PORT}`));