from collections.abc import Sequence

from anydi import singleton
from fansifter_common.email import EmailType
from fansifter_common.utils import timezone

from email_campaigns.audiences.repositories import AudienceRepository
from email_campaigns.campaigns.exceptions import EmailCampaignNotFoundError
from email_campaigns.campaigns.models import EmailCampaign
from email_campaigns.campaigns.repositories import EmailCampaignRepository
from email_campaigns.campaigns.validators import CampaignValidator
from email_campaigns.config import Settings
from email_campaigns.emails.repositories import EmailAnalyticsRepository


@singleton
class EmailCampaignService:
    def __init__(
        self,
        campaign_validator: CampaignValidator,
        campaign_repository: EmailCampaignRepository,
        email_analytics_repository: EmailAnalyticsRepository,
        audience_repository: AudienceRepository,
        settings: Settings,
    ) -> None:
        self.campaign_validator = campaign_validator
        self.campaign_repository = campaign_repository
        self.email_analytics_repository = email_analytics_repository
        self.audience_repository = audience_repository
        self.settings = settings

    def get_campaign(self, campaign_id: str) -> EmailCampaign:
        email_campaign = self.campaign_repository.get(campaign_id)
        if email_campaign is None:
            raise EmailCampaignNotFoundError
        return email_campaign

    def save_campaign(self, campaign: EmailCampaign) -> None:
        self.campaign_repository.save(campaign)

    def delete_campaign(
        self, campaign: EmailCampaign, identity_id: str | None = None
    ) -> None:
        campaign.deleted_at = timezone.now()
        campaign.deleted_by = identity_id

        self.campaign_repository.save(campaign)

    def prefetch_audience(
        self, campaigns: Sequence[EmailCampaign]
    ) -> Sequence[EmailCampaign]:
        """Prefetch recipients count for draft campaigns."""
        audience_ids = [
            campaign.audience_id
            for campaign in campaigns
            if campaign.audience_id is not None
        ]
        audiences_by_id = {
            audience.id: audience
            for audience in self.audience_repository.find_by_ids(audience_ids)
        }
        for campaign in campaigns:
            if campaign.audience_id and campaign.audience_id in audiences_by_id:
                audience = audiences_by_id[campaign.audience_id]
                campaign.audience = audience
        return campaigns

    def prefetch_analytics(
        self, campaigns: Sequence[EmailCampaign]
    ) -> Sequence[EmailCampaign]:
        return self.email_analytics_repository.prefetch_analytics(
            campaigns,
            email_type=EmailType.CAMPAIGN,
        )

    def should_enqueue_campaign(self, campaign: EmailCampaign) -> bool:
        return campaign.is_ready_for_queue(
            window_minutes=self.settings.campaign_schedule_in_queue_minutes,
        )