index.js

require('dotenv').config()
const express = require('express')
const app = express()
const morgan = require('morgan')
const cors = require('cors')
app.use(express.json())
app.use(express.static('build'))
morgan.token('data', function (req) { return JSON.stringify(req.body) })
app.use(morgan(':method :url :status :res[content-length] - :response-time ms :data'))
app.use(cors())

const Person = require('./models/person')

app.get('/api/persons', (request, response) => {
  Person.find({}).then(result => {
    response.json(result)
  })
})

app.get('/api/info', (request, response) => {
  Person.find({}).then(result => {
    const len = result.length
    const date = new Date()
    response.send(`The phonebook site has ${len} people.`+ '\n' + date)
  })
})

app.get('/api/persons/:id', (request, response, next) => {
  Person.findById(request.params.id)
    .then(person => {
      if (person) {
        response.json(person)
	    } else {
        response.status(404).end()
	    }
    })
    .catch(error => next(error))
})

app.delete('/api/persons/:id', (request, response, next) => {
  Person.findByIdAndRemove(request.params.id)
    .then(() => {
	    response.status(204).end()
    })
    .catch(error => next(error))
})

app.post('/api/persons', (request, response, next) => {
  const body = request.body
  if (!body.name) {
    return response.status(400).json({
      error: 'name missing'
    })
  } else if (!body.number) {
    return response.status(400).json({
      error: 'number missing'
    })
  }

  Person.find({ name: body.name })
    .then(person => {
	    if (person.length !== 0) {
        return response.status(400).json({
		    error: 'Duplicate name'
        })
	    } else {
        const person = new Person({
		    name: body.name,
		    number: body.number,
        })

        person.save().then(savedPerson => {
		    return response.json(savedPerson)
        })
		    .catch(error => next(error))
	    }
    })
    .catch(error => next(error))
})

app.put('/api/persons/:id', (request, response, next) => {
  const body = request.body

  const person = {
    number: body.number,
  }

  Person.findByIdAndUpdate(request.params.id, person, { new: true, runValidators: true, context: 'query' })
    .then(updatedPerson => {
      response.json(updatedPerson)
    })
    .catch(error => next(error))
})


const errorHandler = (error, request, response, next) => {
  console.error(error.message)

  if (error.name === 'CastError') {
    return response.status(400).send({ error: 'malformatted id' })
  } else if (error.name === 'ValidationError') {
    return response.status(400).json({ error: error.message })
  }

  next(error)
}

// this has to be the last loaded middleware.
app.use(errorHandler)

const PORT = process.env.PORT
app.listen(PORT, () => {
  console.log(`Server running on port ${PORT}`)
})