index.js

const express = require("express");
const morgan = require("morgan");
const cors = require("cors");

const entryModel = require("./models/entry");
//  data for the application
let data = [
  {
    id: 1,
    name: "Arto Hellas",
    number: "040-123456",
  },
  {
    id: 2,
    name: "Ada Lovelace",
    number: "39-44-5323523",
  },
  {
    id: 3,
    name: "Dan Abramov",
    number: "12-43-234345",
  },
  {
    id: 4,
    name: "Mary Poppendieck",
    number: "39-23-6423122",
  },
  {
    id: 5,
    name: "Fiona Poppendieck",
    number: "39-23-6423123",
  },
];


// initializing the server app
const server = express();

// cors handling
server.use(cors())

// need the following parser that allows easy access to request body that contains the post info
server.use(express.json())

// morgan token to display a POST requests body
morgan.token('body', function(req, res){
  return JSON.stringify(req.body)
});

// following logger used to log HTTP requests made to the server
server.use(morgan(':method :url :status :res[content-length] - :response-time ms :body'))

server.use(express.static('build'))

const generateRandomId = () => {
  return Math.floor(Math.random() * 10000)
}

// api definitions
server.get("/", (req, res) =>
  res.send("<h1>Hello! this is the server speaking...</h1>")
);

server.get("/info", (req, res, next) => {
  let timestamp = new Date();
  let day = new Intl.DateTimeFormat("en-US", { weekday: "short" }).format(
    timestamp
  );
  let month = new Intl.DateTimeFormat("en-US", { month: "short" }).format(
    timestamp
  );
  let date = timestamp.getDate();
  let year = timestamp.getFullYear();
  let time = timestamp.toTimeString();
  
  return entryModel.count({})
  .then(dbRes => {
    res.send( `<div>Phonebook has info for ${dbRes} people</div><div>${day} ${month} ${date} ${year} ${time}</div>` );
  })
  .catch(err => next(err))
  
});

server.get("/api/persons", (req, res, next) => {
  return entryModel.find({})
  .then(dbRes => res.json(dbRes))
  .catch(err => {
    console.log('Something went wrong while fetching all entries:',err)
    next(err)
  })
  
});

server.post("/api/persons", (req, res, next) => {
  let body = req.body
  if(!body) {
    res.status(400).json({ error: 'content missing' })
  }
  else{
    const entry = new entryModel({...body })
    return entry.save()
    .then(dbRes => res.json(dbRes))
    .catch(err => next(err))
    }
  });

server.get("/api/persons/:id", (req, res, next) => {
  const id = req.params.id;
  return entryModel.findOne({ _id: id })
  .then(dbRes => {
    if (dbRes) res.json(dbRes);
    else res.status(404).json({ error: `No entry with id- ${id} found` })
  })
  .catch(err => next(err))
});

server.put("/api/persons/:id", (req, res, next) => {
  const id = req.params.id;
  let body = req.body;
  if(!body) {
    res.status(400).json({ error: 'content missing' })
  }
  else{
    return entryModel.findOneAndUpdate({ _id: id }, { "number": body.number }, { runValidators: true })
    .then(dbRes => {
      console.log(dbRes)
      if(dbRes != null ) res.status(200).json({ message: `Successfully updated number for entry with id-${id}`})
      else res.status(404).json({ error: `No entry with id- ${id} was found for updation` })
    })
    .catch(err => next(err))
  }
})

server.delete("/api/persons/:id", (req, res, next) => {
  const id = req.params.id;
  return entryModel.deleteOne({_id: id })
  .then(dbRes => {
    if(dbRes.deletedCount > 0) res.status(200).json({ message: `Successfully deleted entry for the phonebook.` })
    else res.status(404).json({ message: `Entry with id-${id} does not exist in the database` })
  })
  .catch(err => next(err))
})

// making the server listen to requests on a port
const PORT = process.env.PORT || 3001;
server.listen(PORT, () => {
  console.log(`Server running on port ${PORT}`);
});

// error handling middleware
const unknownEndpoint = (req, res) => {
  res.status(404).send({ error: 'Invalid endpoint' })
}
server.use(unknownEndpoint)

const errorHandler = (error, req, res, next) => {
  if(error.name === 'CastError'){
    return res.status(400).json({ error: 'Malformatted id' })
  }
  else if (error.name === 'ValidationError') {
    return res.status(400).json({ error: error.message })
  }
  next(error)
}
server.use(errorHandler)