from datetime import datetime, timedelta, UTC

from cryptography.fernet import Fernet
from jose import jwt
from passlib.context import CryptContext
from pydantic import EmailStr

from app.config import settings
from app.exceptions import (
	UserDontHavePermissionException,
	IncorrectAuthDataException,
	UserNotFoundException,
	UserMustConfirmEmailException,
)
from app.unit_of_work import UnitOfWork
from app.users.schemas import SUser, SConfirmationData, SInvitationData

pwd_context = CryptContext(schemes=["bcrypt"], deprecated="auto")

cipher_suite = Fernet(settings.INVITATION_LINK_TOKEN_KEY)


def get_password_hash(password: str) -> str:
	return pwd_context.hash(password)


def verify_password(plain_password: str, hashed_password: str) -> bool:
	return pwd_context.verify(plain_password, hashed_password)


def create_access_token(data: dict[str, str | datetime]) -> str:
	to_encode = data.copy()
	expire = datetime.now(UTC) + timedelta(days=30)
	to_encode.update({"exp": expire})
	encoded_jwt = jwt.encode(to_encode, settings.SECRET_KEY, settings.ALGORITHM)
	return encoded_jwt


def encode_invitation_token(user_data: SInvitationData) -> str:
	invitation_token = cipher_suite.encrypt(user_data.model_dump_json().encode())
	return invitation_token.decode()


def decode_invitation_token(invitation_token: str) -> SInvitationData:
	user_code = invitation_token.encode()
	user_data = cipher_suite.decrypt(user_code)
	return SInvitationData.model_validate_json(user_data)


def encode_confirmation_token(user_data: SConfirmationData) -> str:
	invitation_token = cipher_suite.encrypt(user_data.model_dump_json().encode())
	return invitation_token.decode()


def decode_confirmation_token(invitation_token: str) -> SConfirmationData:
	user_code = invitation_token.encode()
	user_data = cipher_suite.decrypt(user_code)
	return SConfirmationData.model_validate_json(user_data)


class AuthService:
	@staticmethod
	async def authenticate_user_by_email(uow: UnitOfWork, email: EmailStr, password: str) -> SUser | None:
		async with uow:
			user = await uow.user.find_one_or_none(email=email)
			if not user or not verify_password(password, user.hashed_password):
				return None
			return user

	@staticmethod
	async def authenticate_user_by_username(uow: UnitOfWork, username: str, password: str) -> SUser | None:
		async with uow:
			user = await uow.user.find_one_or_none(username=username)
			if not user or not verify_password(password, user.hashed_password):
				return None
			return user

	@classmethod
	async def authenticate_user(cls, uow: UnitOfWork, email_or_username: str, password: str) -> SUser:
		user = await cls.authenticate_user_by_email(uow, email_or_username, password)
		if not user:
			user = await cls.authenticate_user_by_username(uow, email_or_username, password)
		if not user:
			raise IncorrectAuthDataException
		return user

	@staticmethod
	async def check_verificated_user(uow: UnitOfWork, user_id: int) -> bool:
		async with uow:
			user = await uow.user.find_one_or_none(id=user_id)
			if not user:
				raise UserNotFoundException
			return user.role >= settings.VERIFICATED_USER

	@classmethod
	async def check_verificated_user_with_exc(cls, uow: UnitOfWork, user_id: int):
		if not await cls.check_verificated_user(uow=uow, user_id=user_id):
			raise UserMustConfirmEmailException

	@staticmethod
	async def get_user_allowed_chats_id(uow: UnitOfWork, user_id: int) -> list[int]:
		async with uow:
			user_allowed_chats = await uow.user.get_user_allowed_chats(user_id)
			user_allowed_chats_id = [chat["chat_id"] for chat in user_allowed_chats]
			return user_allowed_chats_id

	@classmethod
	async def validate_user_access_to_chat(cls, uow: UnitOfWork, user_id: int, chat_id: int) -> bool:
		user_allowed_chats = await cls.get_user_allowed_chats_id(uow=uow, user_id=user_id)
		if chat_id not in user_allowed_chats:
			raise UserDontHavePermissionException
		return True

	@staticmethod
	async def validate_user_admin(uow: UnitOfWork, user_id: int) -> bool:
		async with uow:
			user_role = await uow.user.get_user_role(user_id=user_id)
			if user_role == settings.ADMIN_USER:
				return True
			return False