from __future__ import annotations
from datetime import datetime
from typing import Optional, TYPE_CHECKING
from sqlalchemy import Boolean, DateTime, ForeignKey, Integer, String, Text, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column, relationship
from sqlalchemy.sql import func
from src.apps.base.models.base import Base

if TYPE_CHECKING:
    from src.apps.merchants.models.merchant import Merchant
    from src.apps.feature_control.models.feature_flag import FeatureFlag


class MerchantFeatureOverride(Base):
    __tablename__ = "merchant_feature_overrides"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    merchant_id: Mapped[int] = mapped_column(
        Integer, ForeignKey("merchants.id"), nullable=False, index=True
    )
    feature_slug: Mapped[str] = mapped_column(
        String(100), ForeignKey("feature_flags.slug"), nullable=False, index=True
    )
    is_enabled: Mapped[bool] = mapped_column(Boolean, nullable=False)
    reason: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
    set_by: Mapped[Optional[int]] = mapped_column(Integer, ForeignKey("users.id"), nullable=True)
    set_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), nullable=False
    )

    __table_args__ = (
        UniqueConstraint("merchant_id", "feature_slug", name="uq_merchant_feature_override"),
    )

    merchant: Mapped["Merchant"] = relationship("Merchant")
    feature: Mapped["FeatureFlag"] = relationship("FeatureFlag")