from dataclasses import dataclass

from campaigns.connectors.aws.kms import BaseKMS
from campaigns.connectors.db import Database, session_context
from campaigns.connectors.facebook.base import FacebookClient
from campaigns.core.handler import Handler
from campaigns.meta import constants
from campaigns.meta.dtos import FacebookConnection, FacebookUser
from campaigns.meta.enums import FacebookConnectionStatus
from campaigns.meta.repositories import FacebookAssociationRepository


@dataclass(frozen=True)
class GetFacebookConnectionStatusRequest:
    identity_id: str


@dataclass
class GetFacebookConnectionStatusHandler(
    Handler[GetFacebookConnectionStatusRequest, FacebookConnection],
):
    db: Database
    kms: BaseKMS
    facebook_client: FacebookClient
    facebook_association_repository: FacebookAssociationRepository

    @session_context(in_transaction=False)
    async def handle(
        self, request: GetFacebookConnectionStatusRequest
    ) -> FacebookConnection:
        association = (
            await self.facebook_association_repository.get_by_identity_id_or_none(
                identity_id=request.identity_id
            )
        )
        if not association:
            return FacebookConnection.not_connected()

        required_scopes = constants.REQUIRED_SCOPES

        if not association or (association and not association.is_connected):
            return FacebookConnection.not_connected()

        if association.is_expired:
            return FacebookConnection(
                user=FacebookUser(id=association.user_id, name=association.user_name),
                status=FacebookConnectionStatus.INVALID,
            )

        access_token = await self.kms.decrypt(
            association.token, context={"field": "token"}
        )
        debug_token = await self.facebook_client.debug_token(access_token)

        if not debug_token.is_valid:
            return FacebookConnection(
                user=FacebookUser(id=association.user_id, name=association.user_name),
                status=FacebookConnectionStatus.INVALID,
            )

        api_user = await self.facebook_client.get_user(
            user_id=association.user_id,
            user_access_token=access_token,
        )

        user = FacebookUser.from_api_obj(api_user)
        user.granted_scopes = debug_token.scopes

        if not user.has_pages_scope():
            return FacebookConnection(
                user=user, status=FacebookConnectionStatus.NO_PAGES
            )

        if not user.scopes_sufficient(scopes=required_scopes):
            return FacebookConnection(
                user=user,
                status=FacebookConnectionStatus.SCOPES_MISSING,
            )

        return FacebookConnection(
            user=user,
            status=FacebookConnectionStatus.CONNECTED,
        )