server.js

const express = require('express')
const app = express()
const cors = require('cors')
require('dotenv').config()
const validator = require('validator')
const bodyParser = require('body-parser')
const { format, parseISO } = require('date-fns')
const { connecter } = require('./src/database')

const  {
  newID,
  Users,
  createAndSaveUser,
  findUser,
  findUsers,
  deleteUser,
  deleteUsers,
  deleteAllUsers,
} = require('./src/model/users');
const {
  Logs,
  createAndSaveLogs,
  findLog,
  findLogs,
  findLogsByUser,
  findLogsByDesc,
  deleteAllLogs,
  deleteLogs,
  deleteLog,
} = require('./src/model/logs');

deleteLogs('test');
deleteUsers('fcc');

class Final extends Object{
  constructor(){
    super();
    this.result = undefined;
  }
}


//log all request
//request object, response object, next function
const posthandler = (req,res,next) => {
    //log the request
    console.log(`${req.method} ${req.path} - ${req.ip}`);
    // you need to declare, coz your server will get stuck
    next();
}
//report result (callback)
const done = (error,result) => {
    console.log(result);
}
const doneresult = (error, result) => {
  return result;
}

//GET /api/users
//display all users
const allUsers = async (req,res,next) => {
  findUsers(null,done)
  .then(result => {
    res.send(result);
  });
}

//POST /api/users
//this function will add new user
const newUser = async (req,res,next) => {
  const username = req.body.username;
  //add first to mongodb atlas using User
  //use async
  if (validator.matches(username,/\w+/)) {
    const id = newID();
    createAndSaveUser({username:username,_id:id},done)
    res.send({ username : `${username}`, _id:`${id}`});
 } else {
   res.send('')
 }

}

//POST api/users/:_id/exercises
//this function will add new log to db
//steps:
//1. check if userid is valid
//2. check if user exists, findUser
//3. if exists get all inputs from req.body
// and check for conformity
// if pass:
//4. call createAndSaveLogs with the inputs
//5. upon save, send an object
const newLog = async (req,res,next) => {
  const userid = req.params._id;
  if (!validator.isAlphanumeric(userid)){
    res.send('')
  }

  findUser(userid)
  .then(user=> {
    if (user===null){
      res.send('')
    }
    else {

      const desc = req.body.description;
      const duration = req.body.duration;
      let date = req.body.date || Date.now();
      date = new Date(date);
      if ((validator.matches(desc,/[\w-$&\\.\\+\\\\\\*\\/\[\]#@!%^\{\}]+/)||desc===undefined||desc==="") && validator.isNumeric(duration) && validator.isDate(date) && date!==null) {
        createAndSaveLogs({user:userid,date:date,duration:Number.parseInt(duration),description:desc}).then(result=>{
          res.send({ username:user.username, description:desc, duration:Number.parseInt(duration), date:date.toDateString(), _id:userid })
        });
      }

    }
  })
  .catch(error=>console.log('error:',error))

}

///GET api/users/:_id/logs?[from=value][to=value][limit=value]
//brackets([]) means optional
//this function will display the logs of a particular user using an _id
//steps:
//1. determine if the user included the optional
//2. check if _id is valid and _limit is a number, findUser
//3. all goes well, check if user (_id) exists
//4. check if the that particular user have logs, findLogs
//5. consolidate these logs and send as an object
const userLogs = async (req,res,next) => {

  const userid = req.params._id;
  const _from = req.query.from;
  const _to = req.query.to;

  let searchDate = {};
  let pattern = /\d{4}-\d\d-\d\d/;

  if (_to!==undefined && validator.matches(_to,pattern)) searchDate['$lte'] = new Date(_to);
  if (_from!==undefined && validator.matches(_from,pattern)) searchDate['$gte'] = new Date(_from);

  const _limit = !isNaN(req.query.limit)?Number.parseInt(req.query.limit):0;

  const toSearch = Object.keys(searchDate).length===0?{user:userid}:{user:userid,date:searchDate};

  if (!validator.isAlphanumeric(userid) && isNaN(_limit)) res.send('');
  else {
      findUser(userid)
      .then(user => {

          if (user===null){
            res.send('');
          }
          else {
              let cleanuser = {username: user.username, count: 0, _id:user.id, log: []}
              findLogs(toSearch,_limit,done).then(logs => {
                  if (logs!==null) {
                      const count = logs.length;
                      let cleanlogs = Object.assign([],logs);
                      cleanlogs = cleanlogs.map(log => {

                          const logduration = (typeof log.duration)==='number'?log.duration:Number.parseInt(log.duration);

                          return {description: log.description, duration: logduration, date:format(log.date,'EEE MMM dd yyyy')}
                      });
                      cleanuser['count']=count;
                      cleanuser['log']=cleanlogs;
                      console.log(cleanuser);

                  }
                  res.send(cleanuser);
              });

          }
      })
      .catch(error=>console.log('error:',error))
  }

}

app.use(cors())
app.use(express.static('public'))
app.use(bodyParser.urlencoded({ extended: false }))
app.use(bodyParser.json())
app.use(posthandler);
app.get('/', (req, res) => {
  res.sendFile(__dirname + '/views/index.html')
});


app.route('/api/users').post(newUser).get(allUsers);
app.get('/api/users/exercises',(req,res)=>res.send('Invalid ID!'));
app.post('/api/users/:_id/exercises',newLog)
app.get('/api/users/:_id/logs',userLogs)


const listener = app.listen(process.env.PORT || 3000, () => {
  console.log('Your app is listening on port ' + listener.address().port)
})