import logging
from dataclasses import dataclass
from datetime import UTC, datetime, timedelta

from fansifter_common.adapters.db import Database

from app.adapters.aws.kms import KMSClient
from app.adapters.database.repository import AdAccountRepository
from app.adapters.meta.client import FacebookClient
from app.adapters.tiktok.client import TiktokClient
from app.models import CustomAudience, Event

logger = logging.getLogger(__name__)


@dataclass(kw_only=True)
class EventHandler:
    db: Database
    kms_client: KMSClient
    ad_account_repository: AdAccountRepository
    facebook_client: FacebookClient
    tiktok_client: TiktokClient

    def handle(self, event: Event) -> None:
        logger.info(
            "Starting deleting outdated audiences for %s platform, %s account",
            event.platform,
            event.ad_account,
        )
        with self.db.session_factory():
            encrypted_token = self.ad_account_repository.get_api_token(
                event.platform, event.ad_account
            )
        api_token = self.kms_client.decrypt(encrypted_token, context={"field": "token"})

        client: FacebookClient | TiktokClient

        if event.platform == "META":
            client = self.facebook_client
        elif event.platform == "TIKTOK":
            client = self.tiktok_client
        else:
            raise NotImplementedError(
                f"Client is not implemented for {event.platform} platform"
            )

        audiences = client.get_audiences(event.ad_account, api_token)
        outdated_audiences = self.filter_outdated_audiences(
            audiences, event.audience_ttl_days
        )
        if outdated_audiences:
            client.delete_audiences(event.ad_account, outdated_audiences, api_token)
            logger.info(
                "Outdated audiences for %s platform, %s account was deleted",
                event.platform,
                event.ad_account,
            )
        else:
            logger.info(
                "No outdated audiences was found for %s platform", event.platform
            )

    def filter_outdated_audiences(
        self, audiences: list[CustomAudience], audience_ttl_days: int
    ) -> list[CustomAudience]:
        now = datetime.now(UTC)
        outdated_audiences = []

        for audience in audiences:
            if audience.time_created + timedelta(days=audience_ttl_days) < now:
                outdated_audiences.append(audience)

        return outdated_audiences