import bcrypt
from typing import Tuple, Union
from mysql.connector import Error as mysqlError

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.services.user import user_helper as helper
from app.messages.mail_responses.user_email import USER_EMAIL_SUCCESSFULLY_REGISTERED


def register(
    username: str, displayname: str, email: str, password: str
) -> Tuple[Union[dict, str], int]:
    """
    Registers a new user with the provided username, email, and password.

    :param username: User's username.
    :type username: str
    :param email: User's email address.
    :type email: str
    :param password: User's password.
    :type password: str
    :return: Tuple containing a dictionary and an HTTP status code.
    :rtype: Tuple[Union[dict, str], int]
    """

    try:
        if not helper.verify_username(username):
            return response.INVALID_USERNAME_FORMAT

        if not helper.verify_displayname(displayname):
            return response.INVALID_DISPLAYNAME_FORMAT

        if not helper.verify_email(email):
            return response.INVALID_EMAIL_FORMAT

        if not helper.verify_password(password):
            return response.INVALID_PASSWORD_FORMAT

        hashed_password = bcrypt.hashpw(password.encode("utf-8"), bcrypt.gensalt())

        new_user: User = User(
            username=username,
            displayname=displayname,
            email=email,
            password=hashed_password,
        )

        user_db.insert_user(new_user)

    except mysqlError as e:
        if "email" in e.msg:
            return response.EMAIL_ALREADY_IN_USE
        if "username" in e.msg:
            return response.USERNAME_ALREADY_IN_USE

        return errors.UNKNOWN_DATABASE_ERROR(e)

    send_mail(USER_EMAIL_SUCCESSFULLY_REGISTERED, new_user.email)

    return response.USER_CREATED_SUCCESSFULLY