anuj1

const express = require('express');
const { ObjectId } = require('mongodb');
const {connectToDb, getDb} = require('./db')

const app = express();

let db;

connectToDb((err) =>{
    if(!err){
        app.listen(3000,()=>{
            console.log("app listening on post 3000")
        })
        db = getDb();
    }
})

app.use(express.json());

app.get('/books',(req,res)=>{
    let books = []
    db.collection('books')
    .find().sort({_id : 1})
    .forEach((book)=> books.push(book))
    .then(()=>{
        res.status(200).json(books);
    })
    .catch(()=>{
        console.log(err);
        res.status(500).sendDate('Not found');
    })
})

app.get('/books/:id',(req,res)=>{
    if(ObjectId.isValid(req.params.id)){
        db.collection('books')
        .findOne({_id : ObjectId(req.params.id)})
        .then((book) => res.status(200).json(book))
        .catch((err)=>res.status(400).json("Not found"))
    }
})

app.delete('/books/:id',(req,res)=>{
    if(ObjectId.isValid(req.params.id)){
        db.collection('books')
        .delete({_id : ObjectId(req.params.id)})
        .then((msg) => res.status(200).json(msg))
        .catch((err)=>res.status(400).json("Not found"))
    }
})

app.post('/books',(req,res)=>{
    db.collection('books')
    .insertOne(req.body)
    .then((msg) => res.json(msg))
    .catch((err) => res.json(err))
})

app.patch('/books/:id',(req,res)=>{
    const update = req.body;
    db.collection('books')
    .updateOne({_id : ObjectId(req.params.id)},{$set : {update}})
    .then((msg) => res.json(msg))
    .catch((err) => res.json(err))
})