from dataclasses import dataclass

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

from email_campaigns.adapters.db.decorators import transactional
from email_campaigns.campaigns.enums import EmailCampaignStatus
from email_campaigns.campaigns.exceptions import (
    CampaignAlreadyQueuedError,
    EmailCampaignMustBeScheduledError,
)
from email_campaigns.campaigns.services import EmailCampaignService


@dataclass(kw_only=True)
class UnscheduleCampaignRequest(AuthRequest):
    campaign_id: str


@singleton
class UnscheduleCampaignHandler:
    permission = Permission("email_campaign", "schedule")

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

    @transactional
    def handle(self, request: UnscheduleCampaignRequest) -> None:
        campaign = self.campaign_service.get_campaign(request.campaign_id)

        self.auth_service.authorize_account(
            request.identity_id,
            permission=self.permission,
            account=campaign.account,
        )

        # Do not allow un-scheduling of non-scheduled campaigns
        if not campaign.is_scheduled:
            raise EmailCampaignMustBeScheduledError

        # Do not allow un-scheduling of campaigns
        # that are scheduled to be sent in the period
        if self.campaign_service.should_enqueue_campaign(campaign):
            raise CampaignAlreadyQueuedError

        campaign.status = EmailCampaignStatus.DRAFT
        campaign.send_at = None
        campaign.scheduled_at = None
        campaign.send_at_timezone = None
        campaign.recipients_count = 0
        campaign.updated_by = request.identity_id

        # Save the email campaign
        self.campaign_service.save_campaign(campaign)