import datetime
from typing import Tuple, Union

import bcrypt
from mysql.connector import Error as mysqlError
from flask_jwt_extended import create_access_token

import app.messages.api_responses.user_responses as response
import app.messages.api_errors as errors
from app.db import user_db
from app.mail.mail import send_mail
from app.models.user_model import User
from app.messages.mail_responses.user_email import USER_EMAIL_SUCCESSFULLY_LOGGED_IN


def login(username: str, password: str) -> Tuple[Union[dict, str], int]:
    """
    Authenticates a user with the provided username and password.

    :param username: User's username.
    :type username: str
    :param password: User's password.
    :type password: str
    :return: Tuple containing a dictionary with a token and an HTTP status code.
    :rtype: Tuple[Union[dict, str], int]
    """
    try:
        user: User = user_db.fetch_by_username(username)

        if user is None:
            return response.USERNAME_NOT_FOUND

        if not bcrypt.checkpw(password.encode("utf-8"), user.password.encode("utf-8")):
            return response.INCORRECT_PASSWORD

        expire = datetime.timedelta(hours=1)
        token = create_access_token(identity=user.user_id, expires_delta=expire)

        send_mail(USER_EMAIL_SUCCESSFULLY_LOGGED_IN, user.email)

        return {"token": token}, 200

    except mysqlError as e:
        return errors.UNKNOWN_DATABASE_ERROR(e)