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

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

from dmp.ad_reporting.dtos import (
    AdReportingAd,
    AdReportingAdCriteria,
    AdReportingSummary,
)
from dmp.ad_reporting.enums import AdReportingObjective, AdReportingPlatform
from dmp.ad_reporting.repositories import (
    AdReportingAdRepository,
)
from dmp.ad_reporting.services import (
    AdReportingAccountService,
    AdReportingBenchmarkService,
)
from dmp.ad_reporting.types import AdReportingAdOrderBy


@dataclass(kw_only=True)
class GetAdReportingAdsRequest(AuthRequest):
    DEFAULT_LIMIT: ClassVar[int] = 25
    DEFAULT_OFFSET: ClassVar[int] = 0
    DEFAULT_ORDER_BY: ClassVar[list[AdReportingAdOrderBy]] = [
        "startAt.desc",
        "name.asc",
    ]

    search: str | None
    campaign_id: str | None
    ad_set_id: str | None
    global_participant_id: str | None
    platform: AdReportingPlatform | None
    objective: AdReportingObjective | None
    countries: list[str] | None = None
    order_by: list[AdReportingAdOrderBy]
    limit: int
    offset: int


@dataclass
class GetAdReportingAdsResponse:
    items: Sequence[AdReportingAd]
    summary: AdReportingSummary
    # deprecated
    total: int = field(init=False)

    def __post_init__(self) -> None:
        self.total = self.summary.total


@singleton
class GetAdReportingAdsHandler:
    permission = Permission("ad_campaign", "view")

    def __init__(
        self,
        auth_service: AuthService,
        ad_repository: AdReportingAdRepository,
        account_service: AdReportingAccountService,
        benchmark_service: AdReportingBenchmarkService,
    ) -> None:
        self.auth_service = auth_service
        self.ad_repository = ad_repository
        self.account_service = account_service
        self.benchmark_service = benchmark_service

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

        ad_account_labels = self.account_service.get_allowed_ad_account_labels(
            account_access, platform=request.platform
        )

        if not ad_account_labels:
            return GetAdReportingAdsResponse(items=[], summary=AdReportingSummary())

        criteria = AdReportingAdCriteria(
            search=request.search,
            ad_set_id=request.ad_set_id,
            global_participant_id=request.global_participant_id,
            platform=request.platform,
            objective=request.objective,
            campaign_ids={request.campaign_id} if request.campaign_id else None,
            account_ids=set(ad_account_labels.keys()),
            countries=request.countries,
        )

        summary = self.ad_repository.summary_by_criteria(criteria)

        if summary.total == 0:
            return GetAdReportingAdsResponse(items=[], summary=summary)

        ads = self.ad_repository.find_by_criteria(
            criteria,
            order_by=request.order_by,
            limit=request.limit,
            offset=request.offset,
        )

        # Prefetch label ad accounts
        for ad in ads:
            ad.accounts = ad_account_labels.get(ad.account_id, set())

        if not request.countries or len(request.countries) <= 1:
            self.benchmark_service.prefetch_campaign_benchmarks(
                items=ads,
                allowed_ad_account_labels=ad_account_labels,
                countries=request.countries,
            )

        return GetAdReportingAdsResponse(items=ads, summary=summary)