app.js

require('dotenv').config();
global.setup={};
const umzug=require('./core/migration');
require('./core/models');
require('./core/function');
require('./core/services');
require('./core/multer')
const express=require('express');
const app=express();
const chalk=require('chalk');
const Confirm=require('prompt-confirm')
const bodyParser=require('body-parser');
const cookieParser=require('cookie-parser');
const authRoutes=require('./routes/auth');
const routes=require('./core/routes');
const fp=require('find-free-port');
const morgan=require('morgan');
const config=require('./config/config.json');
const crons=require('./core/cron');
const swaggerUi=require('swagger-ui-express');
const swaggerFile=require('./swagger_output.json');
//Middleware
app.use(bodyParser.json());
app.use(cookieParser());
app.use('/doc',swaggerUi.serve,swaggerUi.setup(swaggerFile));

let morganBody='';
morgan.token('header', function (req) { return JSON.stringify(req.headers) })
morgan.token('body', function (req) { return (Object.keys(req.body).length==0)?'':JSON.stringify(req.body)})
const {allowBody,allowHeaders}=config;  
if(allowBody && allowHeaders){
    morganBody=':remote-addr - ":method :url HTTP/:http-version" :status :res[content-length] [:date[clf]] :body :header '
}else if(allowBody || allowHeaders){
    morganBody=`:remote-addr - ":method :url HTTP/:http-version" :status :res[content-length] [:date[clf]] ${allowBody?':body':':header'} `
}else{
    morganBody=':remote-addr - ":method :url HTTP/:http-version" :status :res[content-length] [:date[clf]]';
}


app.use(morgan(morganBody));

app.use((req,res,next)=>{
    res.header("Access-Control-Allow-Origin","*");
    res.header(
        "Access-Control-Allow-Headers",
        "Origin, X-Requested-With, Content-Type,Accept, Authorization"
    );
    if(req.method==='OPTIONS'){
        res.header('Access-Control-Allow-Methods','PUT,POST,PATCH,DELETE,GET');
        return res.status(200).json({});
    }
    next();
})



app.use((req,res,next)=>{
    crons.forEach(func=>{
        func();
    })
    next();
})

//Routes
for(let route of routes){
    app[route.method](route.path,route.middlewares,route.action);
}

app.get('/',(req,res)=>{
    res.status(200).send('Homepage');
})

//migration
umzug.pending()
.then(migrations=>{
    if(migrations.length!=0){
        console.log(`All pending migrations are`);
        for(let migration of migrations){
            console.log(chalk.yellow(migration.file));
        }
        new Confirm('Do you want to migrate all the pending migrations (yes)?')
        .run()
        .then(answer=>{
            if(answer){
                umzug.up()
                .then(()=>{
                    console.log(chalk.green('Migration completed!'));
                    listenServer()
                })
            }
        })
    }else{
        console.log(chalk.green('No pending migrations'));
            listenServer();
    }
})

//If no routes was matched show 404 not found error
app.use((req,res,next)=>{
    const error=new Error('Not Found');
    error.statusCode=404;
    next(error);
})
//Express Error Handling Middleware
app.use((err,req,res,next)=>{
    const {statusCode=500,message="Something went wrong"}=err;
    res.status(statusCode).json({
        error:message
    })
    next(err);
})

//Logging the error
app.use((err,req,res,next)=>{
    let caller_line = err.stack.split("\n")[1];
    let index = caller_line.indexOf("at ");
    let clean = caller_line.slice(index+2, caller_line.length);
    let lineNumber=clean.substr(-6,2);
    console.log('Error:'+chalk.red(err.message));
    console.log(chalk.yellow(`Error occured at:`)+clean);
    console.log(chalk.yellow('Line Number in which error occured :')+lineNumber)
})


//my server
let PORT=parseInt(process.env.PORT);
process.on('uncaughtException', (error) => {
    if (error.code === 'EADDRINUSE') {
        fp(PORT).then(([freep]) => {
            new Confirm(`Port no ${PORT} is busy.Do you want to run it on the avalibale port (${freep})?`)
            .run()
            .then(answer=>{
                if(answer){
                    PORT=parseInt(freep);
                    listenServer(); 
                }
            })
        })
        /* console.log(`${PORT} already in use want to use ${freeport}`)
        PORT=parseInt(freeport); */
       // listenServer(); 
    }
})  
function listenServer(){
   app.listen(PORT,()=>{
        console.log(chalk.green(`server is listenining on port ${PORT}`));
    })     
}