from __future__ import annotations

import datetime
from dataclasses import field

import sqlalchemy as sa
from fansifter_common.adapters.db.types import ChoiceType
from fansifter_common.email import EmailType
from fansifter_common.utils import timezone
from fansifter_common.utils.uuid import uuid_string
from sqlalchemy.orm import Mapped, mapped_column, relationship

from email_campaigns.adapters.db import Model
from email_campaigns.audiences.models import Audience
from email_campaigns.campaigns.enums import (
    EmailCampaignCancelReason,
    EmailCampaignStatus,
)
from email_campaigns.emails.models import BaseEmail


class EmailCampaign(BaseEmail, Model, kw_only=True, repr=False):
    __tablename__ = "email_campaign"

    email_type = EmailType.CAMPAIGN

    id: Mapped[str] = mapped_column(primary_key=True, default_factory=uuid_string)
    status: Mapped[EmailCampaignStatus] = mapped_column(
        ChoiceType(EmailCampaignStatus), default=EmailCampaignStatus.DRAFT
    )
    audience_id: Mapped[str | None] = mapped_column(default=None)
    recipients_count: Mapped[int] = mapped_column(default=0)
    scheduled_at: Mapped[datetime.datetime | None] = mapped_column(default=None)
    send_at: Mapped[datetime.datetime | None] = mapped_column(default=None)
    send_at_timezone: Mapped[str | None] = mapped_column(default=None)
    cancel_reason: Mapped[EmailCampaignCancelReason | None] = mapped_column(
        default=None
    )
    cancelled_at: Mapped[datetime.datetime | None] = mapped_column(default=None)

    _audience: Audience | None = field(default=None, init=False, compare=False)

    @property
    def is_draft(self) -> bool:
        return self.status == EmailCampaignStatus.DRAFT

    @property
    def is_scheduled(self) -> bool:
        return self.status == EmailCampaignStatus.SCHEDULED

    def is_ready_for_queue(self, window_minutes: int = 10) -> bool:
        return self.status == EmailCampaignStatus.IN_PROGRESS or (
            self.status == EmailCampaignStatus.SCHEDULED
            and self.send_at is not None
            and timezone.now()
            >= self.send_at - datetime.timedelta(minutes=window_minutes)
        )

    @property
    def audience(self) -> Audience | None:
        return self._audience

    @audience.setter
    def audience(self, audience: Audience | None) -> None:
        if audience is None:
            self._audience = None
            self.audience_id = None
            self.recipients_count = 0
            return

        self._audience = audience

        # Override audience
        if self.audience_id != audience.id:
            self.audience_id = audience.id
            self.recipients_count = audience.fan_count


class CampaignBatch(Model, kw_only=True):
    __tablename__ = "email_campaign_batch"

    id: Mapped[int] = mapped_column(primary_key=True, init=False)
    campaign_id: Mapped[str] = mapped_column(
        sa.ForeignKey(EmailCampaign.id, ondelete="RESTRICT")
    )
    domain_id: Mapped[str]
    provider: Mapped[str]
    batch_size: Mapped[int]
    batch_offset: Mapped[int] = mapped_column(default=0, server_default=sa.text("0"))
    completed_at: Mapped[datetime.datetime | None] = mapped_column(default=None)
    cancelled_at: Mapped[datetime.datetime | None] = mapped_column(default=None)

    # relation
    campaign: Mapped[EmailCampaign | None] = relationship(lazy="raise", init=False)


class DeliveryQuota(Model, kw_only=True):
    """Delivery quota tracking for email sending."""

    __tablename__ = "email_campaign_delivery_quota"

    domain_id: Mapped[str] = mapped_column(primary_key=True)
    provider: Mapped[str] = mapped_column(primary_key=True)
    last_sent_at: Mapped[datetime.datetime | None] = mapped_column(default=None)
    last_hour_sent_emails: Mapped[int] = mapped_column(default=0)
    last_hourly_quota: Mapped[float | None] = mapped_column(default=None)