app.js

var createError = require('http-errors');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var logger = require('morgan');
const dotenv = require('dotenv');
const connectDB = require('./config/db');
const errorHandler = require('./middleware/error');
const multer = require('multer');
const bodyParser = require('body-parser');

// Load environment variables
dotenv.config({ path: '.env' });

var indexRouter = require('./routes/index');
var usersRouter = require('./routes/users');
var midiRouter = require('./routes/midi');
var authRouter = require('./routes/auth');

// Connect to database
connectDB();

var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

// Allow File Upload and saving
const fileStorage = multer.diskStorage({
  destination: (req, file, cb) => {
    cb(null, 'midi_generation/output');
  },
  filename: (req, file, cb) => {
    cb(null, new Date().toISOString() + '-' + file.originalname);
  }
});

const fileFilter = (req, file, cb) => {
  if (
      file.mimetype === 'audio/midi'
  ) {
    cb(null, true);
  } else {
    return cb(new Error('File Type Not Allowed for Upload'), false);
  }
};

app.use(multer({ storage: fileStorage, fileFilter: fileFilter }).single('file'));
app.use(logger('dev'));
app.use(express.json());
app.use(express.urlencoded({ extended: false }));
app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));
app.use(express.static(path.join(__dirname, 'build')));

app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: true }));

app.get('/', (req, res) => {
  res.sendFile(path.join(__dirname, 'build', 'index.html'));
});
app.use('/', indexRouter);
app.use('/api/v1/users', usersRouter);
app.use('/api/v1/auth', authRouter);
app.use('/api/v1/midi', midiRouter);

//TODO look into returning error response
app.use(errorHandler);

app.use((req, res, next) => {
  res.setHeader('Access-Control-Allow-Origin', '*');
  res.setHeader(
      'Access-Control-Allow-Methods',
      'OPTIONS, GET, POST, PUT, PATCH, DELETE'
  );
  res.setHeader('Access-Control-Allow-Headers', 'Content-Type, Authorization');
  if(req.method === 'OPTIONS'){
    return res.sendStatus(200);
  }
  next();
});


// catch 404 and forward to error handler
app.use(function(req, res, next) {
  next(createError(404));
});


// error handler
app.use(function(err, req, res, next) {
  // set locals, only providing error in development
  res.locals.message = err.message;
  res.locals.error = req.app.get('env') === 'development' ? err : {};

  // render the error page
  res.status(err.status || 500);
  res.render('error');
});

module.exports = app;