const express = require("express");

const app = express();

const fs = require("fs");

const { Pool } = require("pg");

const bodyParser = require("body-parser");

const PORT = 4000;

const getFunction = (request, response) => {

//reading file

fs.readFile("hello.json", "utf8", (error, data) => {

const obj = JSON.parse(data);

response.json(obj);

});

};

const pool = new Pool({

user: "postgres",

host: "localhost",

database: "cyf-hotels",

password: "idkfaiddqd",

port: 5432,

});

const dbFunction = (request, response) => {

pool.query("select * from hotels", (error, result) => {

response.json(result.rows);

});

};

//POST endpoint for a new hostel

app.use(bodyParser.json());

app.post("/hotels", function (req, res) {

const newHotelName = req.body.name;

let newHotelRooms = req.body.rooms;

const newHotelPostcode = req.body.postcode;

if (!Number.isInteger(newHotelRooms) || newHotelRooms <= 0) {

return res

.status(400)

.send("The number of rooms should be a positive integer.");

}

pool

.query("SELECT * FROM hotels WHERE name=$1", [newHotelName])

.then((result) => {

if (result.rows.length > 0) {

return res

.status(400)

.send("An hotel with the same name already exists!");

} else {

const query =

"INSERT INTO hotels (name, rooms, postcode) VALUES ($1, $2, $3) RETURNING id";

pool

.query(query, [newHotelName, newHotelRooms, newHotelPostcode])

.then(() => res.status(201).send("Hotel created!"))

.catch((e) => console.error(e));

}

});

});

// POST customers endpoint

app.post("/customers", function (req, res) {

const newCustomerName = req.body.name;

const newCustomerEmail = req.body.email;

const newCustomerAddress = req.body.address;

const newCustomerCity = req.body.city;

const newCustomerPostcode = req.body.postcode;

const newCustomerCountry = req.body.country;

pool

.query("SELECT * FROM customers WHERE name=$1", [newCustomerName])

.then((result) => {

if (result.rows.length > 0) {

return res

.status(400)

.send("A customer with the same name already exists!");

} else {

const query =

"INSERT INTO customers (name, email, address, city, postcode, country ) VALUES ($1, $2, $3, $4, $5, $6) RETURNING id";

pool

.query(query, [

newCustomerName,

newCustomerEmail,

newCustomerAddress,

newCustomerCity,

newCustomerPostcode,

newCustomerCountry,

])

.then(() =>

res.status(201).send(`Customer ${newCustomerId} created!`)

)

.catch((e) => console.error(e));

}

});

});

// customer name, check in date, number of nights, hotel name, hotel postcose.

const getCustomerBookings = (req, res) => {

const customerId = req.params.customerId;

// res.send(customers.find((u) => u.id === customerId));

pool

.query(

`select

c.name as customer_name,

b.checkin_date,

b.nights,

h.name,

h.postcode

from customers c

inner join bookings b on b.customer_id = c.id

inner join hotels h on h.id = b.hotel_id

where c.id =$1 `,

[customerId]

)

.then((result) => res.json(result.rows))

.catch((e) => console.error(e));

};

// const getFunction = (request, response) => {

// //reading file

// const text = fs.readFileSync("hello.json");

// const obj = JSON.parse(text);

// //return content

// return response.json(obj);

// };

const getHotels = async (req, res) => {

try {

const queryRows = await pool.query("SELECT * FROM hotels");

await res.json(queryRows.rows);

} catch (err) {

console.log(err);

}

};

const getHotelById = async (req, res) => {

const hotelId = req.params.hotelId;

pool

.query(

`select

*

from hotels h

where h.id =$1 `,

[hotelId]

)

.then((result) => res.json(result.rows))

.catch((e) => console.error(e));

};

const getCustomers = async (req, res) => {

try {

const queryRows = await pool.query(

`select

* from customers c

order by name`

);

await res.json(queryRows.rows);

} catch (err) {

console.log(err);

}

};

const getCustomerById = async (req, res) => {

const customerId = req.params.customerId;

pool

.query(

`select

*

from customers c

where c.id =$1 `,

[customerId]

)

.then((result) => res.json(result.rows))

.catch((e) => console.error(e));

};

// PATCH FUNCTION

const updateCustomer = async (req, res) => {

const customerId = req.params.customerId;

const newEmail = req.body.email;

const newAddress = req.body.address;

const newCity = req.body.city;

const newPostcode = req.body.postcode;

const newCountry = req.body.country;

if (newEmail.length <= 0) {

return res.status(400).send("The email field shouldn't be empty");

}

pool

.query(

"UPDATE customers SET email=$1 address=$2 city=$3 postcode=$4 country=$5 WHERE id=$6",

[newEmail, newAddress, newCity, newPostcode, newCountry, customerId]

)

.then(() => res.send(`Customer ${customerId} updated!`))

.catch((e) => console.error(e));

};

const deleteCustomer = async (req, res) => {

const customerId = req.params.customerId;

pool

.query("DELETE FROM bookings WHERE customer_id=$1", [customerId])

.then(() => {

pool

.query("DELETE FROM customers WHERE id=$1", [customerId])

.then(() => res.send(`Customer ${customerId} deleted!`))

.catch((e) => console.error(e));

})

.catch((e) => console.error(e));

};

const deleteHotel = async (req, res) => {

const hotelId = req.params.hotelId;

pool

.query("DELETE FROM bookings WHERE hotel_id=$1", [hotelId])

.then(() => {

pool

.query("DELETE FROM hotels WHERE id=$1", [hotelId])

.then(() => res.send(`Hotel ${hotelId} deleted!`))

.catch((e) => console.error(e));

})

.catch((e) => console.error(e));

};

// Finish and Ex 4

app.delete("/hotels/:hotelId", deleteHotel);

app.delete("/customers/:customerId", deleteCustomer);

app.patch("/customers/:customerId", updateCustomer);

app.get("/customers/:customerId/bookings", getCustomerBookings);

app.get("/customers/:customerId", getCustomerById);

app.get("/hotels", getHotels);

app.get("/hotels/:hotelId", getHotelById);

app.get("/customers", getCustomers);

app.get("/hello", getFunction);

app.get("/db", dbFunction);

app.get("/", (req, res) => {

res.json("Welcome to the Hotels application.");

});

app.listen(PORT, () => console.log(`listening to ${PORT}`));