from http import HTTPStatus
from http.cookies import SimpleCookie
from urllib.parse import ParseResult, quote, urlencode, urlunparse

from authlib.oauth2 import OAuth2Error
from authlib.oauth2.rfc6749 import errors
from aws_lambda_powertools import Logger
from aws_lambda_powertools.event_handler import Response
from aws_lambda_powertools.event_handler.api_gateway import Router
from jose.exceptions import JWTError

from jose_ import verify_jwt
from oauth2 import server

router = Router()
logger = Logger(__name__)


@router.get('/authorize')
def authorize():
    current_event = router.current_event
    cookies = _parse_cookies(current_event.get('cookies', []))
    id_token = cookies.get('id_token')
    continue_url = _build_continue_url(
        current_event.path,
        current_event.query_string_parameters,
    )

    login_url = f'/login?continue={continue_url}'

    try:
        if not id_token:
            raise ValueError('Missing id_token')

        user = verify_jwt(id_token)
    except (ValueError, JWTError):
        return Response(
            status_code=HTTPStatus.FOUND,
            headers={'Location': login_url},
        )

    try:
        grant = server.get_consent_grant(
            request=router.current_event,
            end_user={'id': user['sub']},
        )
    except OAuth2Error as err:
        logger.exception(err)
        return dict(err.get_body())

    try:
        return server.create_authorization_response(
            request=router.current_event,
            grant_user={'id': user['sub']},
            grant=grant,
        )
    except errors.OAuth2Error as err:
        logger.exception(err)
        return {}


def _parse_cookies(cookies: list[str] | None) -> dict[str, str]:
    parsed_cookies = {}

    if not cookies:
        return parsed_cookies

    for s in cookies:
        c = SimpleCookie()
        c.load(s)
        parsed_cookies.update({k: morsel.value for k, morsel in c.items()})

    return parsed_cookies


def _build_continue_url(
    path: str,
    query_string_parameters: dict,
) -> str:
    query = urlencode(query_string_parameters)
    return quote(urlunparse(ParseResult('', '', path, '', query, '')), safe='')