from dataclasses import dataclass

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

from dmp.adapters.db import DefaultDB, ReportingDB
from dmp.adapters.features import AUDIENCE_ALLOW_AUDIENCE_EXPORT_TO_FILE, Features
from dmp.audiences.enums import (
    AudienceExportFormat,
    AudienceExportJustification,
    AudienceExportReason,
    AudienceTarget,
)
from dmp.audiences.exceptions import AudienceTargetNotSupportedError, EmptyAudienceError
from dmp.audiences.models import AudienceExport
from dmp.audiences.repositories import AudienceExportRepository
from dmp.audiences.services import AudienceService


@dataclass
class ExportAudienceRequest(AuthRequest):
    audience_id: str
    reason: AudienceExportReason
    justification: AudienceExportJustification
    reason_notes: str | None


@singleton
class ExportAudienceHandler:
    permission = Permission("audience", "export_to_csv")

    def __init__(
        self,
        db: DefaultDB,
        reporting_db: ReportingDB,
        auth_service: AuthService,
        audience_service: AudienceService,
        audience_export_repository: AudienceExportRepository,
        features: Features,
    ) -> None:
        self.db = db
        self.reporting_db = reporting_db
        self.auth_service = auth_service
        self.audience_service = audience_service
        self.audience_export_repository = audience_export_repository
        self.features = features

    def handle(self, request: ExportAudienceRequest) -> AudienceExport:
        if not self.features.is_on_for_identity(
            feature_flag_name=AUDIENCE_ALLOW_AUDIENCE_EXPORT_TO_FILE,
            identity_id=request.identity_id,
        ):
            raise PermissionDenied

        with self.db.transaction():
            audience = self.audience_service.get_audience(request.audience_id)

            self.auth_service.check_account_resource(
                request.identity_id,
                account=audience.account,
                permission=self.permission,
                resource_id=audience.id,
            )

            if audience.target == AudienceTarget.TEXT:
                raise AudienceTargetNotSupportedError(
                    "Export audience target not supported"
                )

            latest_snapshot = audience.latest_snapshot

            if latest_snapshot is None or not latest_snapshot.fan_count:
                raise EmptyAudienceError

            export = AudienceExport(
                audience=audience,
                snapshot=latest_snapshot,
                format=AudienceExportFormat.CSV,
                reason=request.reason,
                justification=request.justification,
                reason_notes=request.reason_notes,
                created_by=request.identity_id,
            )

            self.audience_service.export_audience_to_csv(export)

            self.audience_export_repository.add(export)

            return export