from collections.abc import Sequence
from dataclasses import dataclass

from anydi import singleton
from fansifter_common.identifiers.types import ProfileToken

from preference_center.profile.cache import ProfileCache
from preference_center.profile.dispatcher import ProfileDispatcher
from preference_center.profile.models import Subscription
from preference_center.profile.services import ProfileService


@dataclass(kw_only=True)
class UpdateSubscriptionsRequest:
    token: ProfileToken
    data: dict[str, bool]


@singleton
class UpdateSubscriptionsHandler:
    def __init__(
        self,
        dispatcher: ProfileDispatcher,
        cache: ProfileCache,
        profile_service: ProfileService,
    ) -> None:
        self.dispatcher = dispatcher
        self.cache = cache
        self.profile_service = profile_service

    def handle(self, request: UpdateSubscriptionsRequest) -> Sequence[Subscription]:
        identifier = self.profile_service.decode_profile_identifier(request.token)

        # Ignore empty update payloads
        if not request.data:
            return []

        profile = self.profile_service.get_profile_by_identifier_cached(identifier)

        changed_subscriptions: list[Subscription] = []
        subscriptions = self.profile_service.get_subscriptions_cached(profile.id)

        # Toggle subscription status flags
        for subscription in subscriptions:
            if subscription.id not in request.data:
                continue
            is_active = request.data[subscription.id]
            if is_active is subscription.is_active:
                continue
            subscription.is_active = is_active
            changed_subscriptions.append(subscription)

        # Skip persistence if nothing changed
        if not changed_subscriptions:
            return subscriptions

        profile.updated_by = identifier.impersonated_by

        # Invalidate cached subscriptions
        self.cache.set_subscriptions(profile.id, subscriptions=subscriptions)

        self.dispatcher.dispatch_subscriptions_updated(
            profile,
            subscriptions=changed_subscriptions,
            origin_id=identifier.origin_id,
            origin_type=identifier.origin_type,
        )

        return subscriptions