server.js

const express = require('express');
const mongoose = require('mongoose');
const cors = require('cors');
const bodyParser = require('body-parser');
const path = require('path');
require('dotenv').config();
const User = require('./models/user');
const Exercise = require('./models/exercise');

const app = express();
const port = process.env.PORT;
const mongoDB = process.env.MONGODB_URI;

mongoose.connect(mongoDB, {
  useNewUrlParser: true,
  useUnifiedTopology: true,
  useFindAndModify: false,
  useCreateIndex: true
});
const db = mongoose.connection;
db.on('error', (err) => { console.log('Mongo DB connection error', err); });
db.once('open', () => { console.log('Mongo DB connected.'); });

app.use(cors({ optionSuccessStatus: 200 }));  // some legacy browsers choke on 204

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

app.use(express.static('public'));

app.get('/', (req, res) => {
  res.sendFile(path.join(__dirname, '/views/index.html'));
});

// Create new User route
app.post('/api/exercise/new-user/', (req, res) => {
  const username = req.body.username;

  if (username === '') {
    res.send('Username cannot be blank');
  } else if (username.length > 10) {
    res.send('Username cannot be greater than 10 characters');
  } else {
    const newUser = new User({
      username,
    });

    newUser.save((err, data) => {
      if (err) {
        if (err.name === 'MongoError' && err.code === 11000) { // Duplicate key error
          res.send('Duplicate username, try a different username');
        } else {
          res.send('Errpr pccurred while saving user');
        }
      } else {
        res.json(data);
      }
    });
  }
});

// Create new Exercise route
app.post('/api/exercise/add', (req, res) => {
  const username = req.body.username;
  const description = req.body.description;
  let duration = req.body.duration;
  let date = req.body.date;
  let userId;

  if (username === undefined || description === undefined || duration === undefined) {
    res.send('Required Field(s) are missing.');
  } else if (username === '' || description === '' || duration === '') {
    res.send('Required Field(s) are blank.');
  } else if (username.length > 10) {
    res.send('Username cannot be greater than 10 characters');
  } else if (description.length > 100) {
    res.send('Description cannot be greater than 100 characters');
  } else if (isNaN(duration)) {
    res.send('Duration must be a number');
  } else if (Number(duration) > 1440) {
    res.send('Duration must be less than 1440 minutes (24 hours)');
  } else if (date !== '' && isNaN(Date.parse(date)) === true) {
    res.send('Date is not a valid date');
  } else {
    // Find userId for username
    User.findOne({ username }, (err, user) => {
      if (err) {
        res.send('Error while searching for username, try again');
      } else if (!user) {
        res.send('Username not found');
      } else {
        userId = user.id;

        // Valiidations passed, convert duration
        duration = Number(duration);

        // Valiidations passed, convert date
        if (date === '') {
          date = new Date();
        } else {
          date = Date.parse(date);
        }

        const newExercise = new Exercise({
          userId,
          description,
          duration,
          date,
        });

        newExercise.save((errSave, data) => {
          if (errSave) {
            res.send('Error occurred while saving exercise');
          } else {
            res.json(data);
          }
        });
      }
    });
  }
});

// Read Exercise route
app.get('/api/exercise/:log', (req, res) => {
  const username = req.query.username;
  let from = req.query.from;
  let to = req.query.to;
  let limit = req.query.limit;
  let userId;
  const query = {};

  // console.log(req.query);

  if (username === undefined) {
    res.send('Required Field(s) are missing.');
  } else if (username === '') {
    res.send('Required Field(s) are blank.');
  } else if (username.length > 10) {
    res.send('Username cannot be greater than 10 characters');
  } else if (from !== undefined && isNaN(Date.parse(from)) === true) {
    res.send('From is not a valid date');
  } else if (to !== undefined && isNaN(Date.parse(to)) === true) {
    res.send('From is not a valid date');
  } else if (limit !== undefined && isNaN(limit) === true) {
    res.send('Limit is not a valid number');
  } else if (limit !== undefined && Number(limit) < 1) {
    res.send('Limit must be greater than 0');
  } else {
    // Find userId for username\
    User.findOne({ username }, (err, user) => {
      if (err) {
        res.send('Error while searching for username, try again');
      } else if (!user) {
        res.send('Username not found');
      } else {
        userId = user.id;
        query.userId = userId;

        if (from !== undefined) {
          from = new Date(from);
          query.date = { $gte: from};
        }

        if (to !== undefined) {
          to = new Date(to);
          to.setDate(to.getDate() + 1); // Add 1 day to include date
          query.date = { $lt: to};
        }

        if (limit !== undefined) {
          limit = Number(limit);
        }

        Exercise.find(query).select('userId description date duration ').limit(limit).exec((errExercise, exercises) => {
          if (err) {
            res.send('Error while searching for exercises, try again');
          } else if (!user) {
            res.send('Exercises not found');
          } else {
            res.json(exercises);
          }
        });
      }
    });
  }
});

const listener = app.listen(port, () => {
  console.log(`Your app is listening on port ${listener.address().port}`);
});