import bcrypt from "bcrypt";
import { Request, Response } from "express";
import jwt from "jsonwebtoken";
import { QueryResult } from "pg";
import db from "../database/postgres.js";
import { ErrorResponse } from "../types/error.js";
import type { LoginRequest } from "../types/request.js";
import type {
    AuthorizedUser,
    DatabaseUser,
    LoginResponse,
} from "../types/user.js";

async function loginUser(req: Request, res: Response) {
    const { email, password } = req.body as LoginRequest;

    if (!email || !password) {
        return res.status(400).json({
            message: "E-mail and password are required.",
        });
    }

    try {
        // Get data for user with login email address
        const queryResult: QueryResult<DatabaseUser> = await db.query(
            "SELECT id, email, password_hash, created_at FROM users WHERE email = $1;",
            [email]
        );

        const user = queryResult.rows[0];

        if (!user) {
            return res.status(401).json({ message: "Login data invalid." });
        }

        // Check if password is correct
        const isValidPassword = await bcrypt.compare(
            password,
            user.password_hash
        );

        if (!isValidPassword) {
            return res.status(401).json({
                message: "The password is incorrect.",
            });
        }

        const userData: AuthorizedUser = {
            id: user.id,
            email: user.email,
            createdAt: user.created_at,
        };

        // Create token for authentication
        const token = jwt.sign(userData, process.env.JWT_SECRET!);

        const loginResponse: LoginResponse = {
            message: "Successful login.",
            user: userData,
            token,
        };

        return res.status(200).json(loginResponse);
    } catch (error) {
        console.error("Error on login attempt: ", error);

        const errorResponse: ErrorResponse = {
            message: "Internal server error on login attempt.",
            error,
        };
        return res.status(500).json(errorResponse);
    }
}

export default loginUser;