var express = require('express')
var app = express()
var MongoClient = require('mongodb').MongoClient
var ObjectID = require('mongodb').ObjectID
const url = "mongodb://localhost:27017"

app.get('/get_user_by_id', (req, res) => {
    MongoClient.connect(url, (err, db) => {
        if(err) throw err;
        var dbo = a(db)
        dbo.collection("users").findOne({_id: ObjectID("5cc6e5bca560a302a84ff60f")}, (err, result) => {
            if(err) throw err;
            res.json(result)
            db.close()
        })
    })
})

app.get('/new_user', (req, res) => {
    let obj = {
        login: req.query.login,
        password: req.query.password
    }
    MongoClient.connect(url, (err, db) => {
        if(err) throw err;
        var dbo = db.db("my_db")
        dbo.collection("users").insertOne(obj, (err, result) => {
            res.json({type: "ok"})
            db.close()
        })
    })
})

app.get('/login', (req, res) => {
    let password = req.query.password
    let obj = {
        login: req.query.login
    }
    MongoClient.connect(url, (err, db) => {
        if(err) throw err;
        var dbo = db.db("my_db")
        dbo.collection("users").findOne(obj, (err, result) => {
            if (err) throw err;
            if(result){
                if(result.password === password){
                    res.json({type: "ok"})
                }else{
                    res.json({type: "bad_password"})
                }
            }else{
                res.json({type: "no"})
            }
            db.close()
        })
    })
})

app.get('/get_user', (req, res) => {
    let obj = {
        login: req.query.login
    }
    MongoClient.connect(url, (err, db) => {
        if(err) throw err;
        var dbo = db.db("my_db")
        dbo.collection("users").findOne(obj, (err, result) => {
            if (err) throw err;
            var user = result;
            delete user.password;
            res.json(user)
            db.close()
        })
    })
})

app.get('/users', (req, res) => {
    MongoClient.connect(url, (err, db) => {
        if(err) throw err;
        var dbo = a(db)
        dbo.collection("users").find({}, { projection: { password: 0 } }).toArray((err, result) => {
            if(err) throw err;
            res.json(result)
            db.close()
        })
    })
})

app.get('/change_password', (req, res) => {
    let obj = {
        login: req.query.login,
        password: req.query.old_password
    }
    MongoClient.connect(url, (err, db) => {
        if(err) throw err;
        var dbo = a(db)
        dbo.collection("users").findOne(obj, (err, result) => {
            if(err) throw err;
            if(result){
                var user = result;
                user.password = req.query.new_password;
                dbo.collection("users").updateOne(obj, {$set: user}, (err, result) => {
                    if(err) throw err;
                    res.json({type: "ok"})
                    db.close()
                })
            }else{
                res.json({type: "bad"})
                db.close()
            }
        })
    })
})

let a = (db) => {
    return db.db("my_db")
}

app.listen(1337, () => {
    console.log("Server listening on port 1337!")
    MongoClient.connect(url, (err, db) => {
        if(err) throw err;
        console.log('Database is connected')
        db.close()
    })
})