from collections.abc import Sequence
from dataclasses import dataclass
from typing import ClassVar

from anydi import singleton
from fansifter_common.auth.requests import AuthAccountFilterRequest
from fansifter_common.auth.services import AuthService
from fansifter_common.auth.types import Permission

from email_campaigns.campaigns.enums import EmailCampaignStatus
from email_campaigns.campaigns.models import EmailCampaign
from email_campaigns.campaigns.repositories import EmailCampaignRepository
from email_campaigns.campaigns.services import EmailCampaignService
from email_campaigns.campaigns.types import EmailCampaignCriteria, EmailCampaignOrderBy
from email_campaigns.rosters.types import FanDataListId


@dataclass(kw_only=True)
class GetCampaignsRequest(AuthAccountFilterRequest):
    DEFAULT_LIMIT: ClassVar[int] = 50
    DEFAULT_OFFSET: ClassVar[int] = 0
    DEFAULT_ORDER_BY: ClassVar[list[EmailCampaignOrderBy]] = ["updatedAt.desc"]

    search: str | None
    fandata_list_ids: set[FanDataListId] | None
    statuses: list[EmailCampaignStatus] | None
    audience_id: str | None = None
    order_by: list[EmailCampaignOrderBy]
    limit: int
    offset: int


@dataclass
class GetCampaignsResponse:
    items: Sequence[EmailCampaign]
    total: int


@singleton
class GetCampaignsHandler:
    permission = Permission("email_campaign", "view")

    def __init__(
        self,
        auth_service: AuthService,
        campaign_repository: EmailCampaignRepository,
        campaign_service: EmailCampaignService,
    ) -> None:
        self.auth_service = auth_service
        self.campaign_repository = campaign_repository
        self.campaign_service = campaign_service

    def handle(self, request: GetCampaignsRequest) -> GetCampaignsResponse:
        account_access = self.auth_service.authorize_for_permission(
            request.identity_id, permission=self.permission
        )

        vendor_ids = account_access.filter_vendor_ids(request.vendor_id)
        subaccount_ids = account_access.filter_subaccount_ids(request.subaccount_id)

        criteria = EmailCampaignCriteria(
            campaign_ids=None,
            vendor_ids=set(vendor_ids),
            subaccount_ids=set(subaccount_ids),
            fandata_list_ids=request.fandata_list_ids,
            search=request.search,
            statuses=request.statuses,
            audience_id=request.audience_id,
        )
        total = self.campaign_repository.count_by_criteria(criteria)
        if total == 0:
            return GetCampaignsResponse(total=0, items=[])

        campaigns = self.campaign_repository.find_by_criteria(
            criteria,
            order_by=request.order_by,
            limit=request.limit,
            offset=request.offset,
        )

        # Prefetch analytics for campaigns
        self.campaign_service.prefetch_analytics(campaigns)

        # Prefetch recipients count for draft campaigns
        self.campaign_service.prefetch_audience(campaigns)

        return GetCampaignsResponse(total=total, items=campaigns)