text: const createError = require('http-errors')
  const express = require('express')
  const path = require('path')
  const cookieParser = require('cookie-parser')
  const logger = require('morgan')
  const validator = require('express-validator')
  const cors = require('cors')
  
  const indexRouter = require('./routes/index')
  const sampleRouter = require('./routes/api/samples')
  const instrumentRouter = require('./routes/api/instruments')
  const mappingRouter = require('./routes/api/mappings')
  
  const app = express()
  
  const swaggerUi = require('swagger-ui-express')
  const swaggerDocument = require('./openapi')
  
  const {NotAudioFileError, DatabaseError} = require('./errors')
  
  // view engine setup
  app.set('views', path.join(__dirname, 'views'))
  app.set('view engine', 'pug')
  
  app.use(logger('dev'))
  app.use(cors())
  app.use(express.json())
  app.use(express.urlencoded({extended: false}))
  app.use(validator())
  app.use(cookieParser())
  app.use(express.static(path.join(__dirname, 'public')))
  app.use('/static', express.static(path.join(__dirname, 'static')))
  
  // router
  app.use('/', indexRouter)
  app.use('/api/samples', sampleRouter)
  app.use('/api/instruments', instrumentRouter)
  app.use('/api/mappings', mappingRouter)
  
  app.use('/api-docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument))
  
  // catch 404 and forward to error handler
  app.use(function (req, res, next) {
    next(createError(404))
  })
  
  app.use(function handleDatabaseError (err, req, res, next) {
    if (err instanceof DatabaseError) {
      return res.status(err.status).json(err)
    }
    next(err)
  })
  
  app.use(function handleMulterError (err, req, res, next) {
    if (err instanceof NotAudioFileError) {
      return res.status(err.status).json(err)
    }
    next(err)
  })
  
  // error handler
  app.use(function handleGenericError (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 : {}
  
    res.status(err.status || 500).json(err)
  })
  
  module.exports = app
  