const express = require('express')
const morgan = require('morgan');
const http = require('http')
const app = express()
const os = require('os');
const jwt = require('jsonwebtoken');
const concat = require('concat-stream');
const { promisify } = require('util');
const sleep = promisify(setTimeout);

app.set('json spaces', 2);
app.set('trust proxy', ['loopback', 'linklocal', 'uniquelocal']);

app.use(morgan('combined'));

app.use(function(req, res, next){
    req.pipe(concat(function(data){
        req.body = data.toString('utf8');
        next();
    }));
});

app.all('*', (req, res) => {
    const echo = {
        path: req.path,
        headers: req.headers,
        method: req.method,
        body: req.body,
        cookies: req.cookies,
        fresh: req.fresh,
        hostname: req.hostname,
        ip: req.ip,
        ips: req.ips,
        protocol: req.protocol,
        query: req.query,
        subdomains: req.subdomains,
        xhr: req.xhr,
        os: {
            hostname: os.hostname()
        },
        connection: {
            servername: req.connection.servername
        }
    };

    if(req.is('application/json')){
        echo.json = JSON.parse(req.body)
    }

    if (process.env.JWT_HEADER) {
        let token = req.headers[process.env.JWT_HEADER.toLowerCase()];
        if (!token) {
            echo.jwt = token;
        } else {
            token = token.split(" ").pop();
            const decoded = jwt.decode(token, {complete: true});
            echo.jwt = decoded;
        }
    }
    const setResponseStatusCode = parseInt(req.headers["x-set-response-status-code"] || req.query["x-set-response-status-code"], 10)
    if (100 <= setResponseStatusCode && setResponseStatusCode < 600) {
        res.status(setResponseStatusCode)
    }

    const sleepTime = parseInt(req.headers["x-set-response-delay-ms"] || req.query["x-set-response-delay-ms"], 0)
    sleep(sleepTime).then(() => {

        if (process.env.ECHO_BACK_TO_CLIENT != undefined && process.env.ECHO_BACK_TO_CLIENT == "false"){
            res.end();
        } else {
            res.json(echo);
        }

        if (process.env.LOG_IGNORE_PATH != req.path) {
            console.log('-----------------')

            let spacer = 4;
            if(process.env.LOG_WITHOUT_NEWLINE){
                spacer = null;
            }

            console.log(JSON.stringify(echo, null, spacer));
        }
    });


});

let httpServer = http.createServer(app).listen(process.env.HTTP_PORT || 8000);
console.log(`Listening on port ${process.env.HTTP_PORT || 8000}`);

let calledClose = false;

process.on('exit', function () {
    if (calledClose) return;
    console.log('Got exit event. Trying to stop Express server.');
    server.close(function() {
        console.log("Express server closed");
    });
});

process.on('SIGINT', shutDown);
process.on('SIGTERM', shutDown);

function shutDown(){
    console.log('Got a kill signal. Trying to exit gracefully.');
    calledClose = true;
    httpServer.close(function() {
        console.log("HTTP servers closed. Asking process to exit.");
    });
}