Backend/src/controllers/auth.controller.js

const userModel = require("../models/user.model")
const bcrypt = require("bcryptjs")
const jwt = require("jsonwebtoken")
const tokenBlacklistModel = require("../models/blacklist.model")

/**
 * @name registerUserController
 * @description register a new user, expects username, email and password in the request body
 * @access Public
 */
async function registerUserController(req, res) {
    try {
        const { username, email, password } = req.body

        if (!username || !email || !password) {
            return res.status(400).json({
                message: "Please provide username, email and password"
            })
        }

        const isUserAlreadyExists = await userModel.findOne({
            $or: [ { username }, { email } ]
        })

        if (isUserAlreadyExists) {
            if (isUserAlreadyExists.email === email) {
                return res.status(400).json({
                    message: "Account already exists with this email address"
                })
            }
            if (isUserAlreadyExists.username === username) {
                return res.status(400).json({
                    message: "Account already exists with this username"
                })
            }
        }

        const hash = await bcrypt.hash(password, 10)

        const user = await userModel.create({
            username,
            email,
            password: hash
        })

        res.status(201).json({
            message: "User registered successfully",
            user: {
                id: user._id,
                username: user.username,
                email: user.email
            }
        })
    } catch (err) {
        console.error("registerUserController error:", err)
        res.status(500).json({ message: "Registration failed. Please try again." })
    }
}


/**
 * @name loginUserController
 * @description login a user, expects email and password in the request body
 * @access Public
 */
async function loginUserController(req, res) {
    try {
        const { email, password } = req.body

        const user = await userModel.findOne({ email })

        if (!user) {
            return res.status(400).json({
                message: "Invalid email or password"
            })
        }

        const isPasswordValid = await bcrypt.compare(password, user.password)

        if (!isPasswordValid) {
            return res.status(400).json({
                message: "Invalid email or password"
            })
        }

        const token = jwt.sign(
            { id: user._id, username: user.username },
            process.env.JWT_SECRET,
            { expiresIn: "1d" }
        )

        res.cookie("token", token, { httpOnly: true, sameSite: "none", secure: true })
        res.status(200).json({
            message: "User loggedIn successfully.",
            user: {
                id: user._id,
                username: user.username,
                email: user.email
            }
        })
    } catch (err) {
        console.error("loginUserController error:", err)
        res.status(500).json({ message: "Login failed. Please try again." })
    }
}


/**
 * @name logoutUserController
 * @description clear token from user cookie and add the token in blacklist
 * @access public
 */
async function logoutUserController(req, res) {
    const token = req.cookies.token

    if (token) {
        await tokenBlacklistModel.create({ token })
    }

    res.clearCookie("token", { httpOnly: true, sameSite: "none", secure: true })

    res.status(200).json({
        message: "User logged out successfully"
    })
}

/**
 * @name getMeController
 * @description get the current logged in user details.
 * @access private
 */
async function getMeController(req, res) {

    const user = await userModel.findById(req.user.id)



    res.status(200).json({
        message: "User details fetched successfully",
        user: {
            id: user._id,
            username: user.username,
            email: user.email
        }
    })

}



module.exports = {
    registerUserController,
    loginUserController,
    logoutUserController,
    getMeController
}