from __future__ import annotations

from datetime import datetime
from decimal import Decimal

from sqlalchemy import DateTime, ForeignKey, Index, JSON, Numeric, String
from sqlalchemy.orm import Mapped, mapped_column

from app.enums.credit_subscription import CreditSubscriptionStatus
from app.models.base import Base, TimestampMixin


class UserCreditSubscription(Base, TimestampMixin):
    __tablename__ = "user_credit_subscriptions"
    __table_args__ = (
        Index("ix_user_credit_subscriptions_current", "user_id", "status", "expires_at"),
        Index("ix_user_credit_subscriptions_expire_due", "status", "expires_at", "id"),
        Index("ix_user_credit_subscriptions_grant_due", "status", "next_grant_at", "id"),
        Index("uq_user_credit_subscriptions_payment", "payment_order_id", unique=True),
    )

    id: Mapped[str] = mapped_column(String(32), primary_key=True)
    user_id: Mapped[str] = mapped_column(
        String(32), ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
    )
    product_id: Mapped[str | None] = mapped_column(
        String(32), ForeignKey("credit_products.id", ondelete="SET NULL"), nullable=True
    )
    payment_order_id: Mapped[str] = mapped_column(
        String(32), ForeignKey("payment_orders.id", ondelete="RESTRICT"), nullable=False
    )
    status: Mapped[str] = mapped_column(
        String(32), nullable=False, default=CreditSubscriptionStatus.PENDING.value,
        server_default=CreditSubscriptionStatus.PENDING.value,
    )
    purchase_scene: Mapped[str] = mapped_column(String(24), nullable=False)
    tier_code: Mapped[str] = mapped_column(String(32), nullable=False)
    tier_rank: Mapped[int] = mapped_column(nullable=False)
    billing_cycle: Mapped[str] = mapped_column(String(24), nullable=False)
    anchor_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
    start_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
    expires_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), nullable=False)
    next_grant_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True), nullable=True)
    monthly_grant_credits_snapshot: Mapped[Decimal] = mapped_column(Numeric(20, 2), nullable=False)
    grant_count: Mapped[int] = mapped_column(nullable=False)
    granted_count: Mapped[int] = mapped_column(nullable=False, default=0, server_default="0")
    paid_amount_snapshot: Mapped[Decimal] = mapped_column(Numeric(20, 2), nullable=False)
    product_snapshot_json: Mapped[dict] = mapped_column(JSON, nullable=False)
    source_subscription_id: Mapped[str | None] = mapped_column(
        String(32), ForeignKey("user_credit_subscriptions.id", ondelete="SET NULL"), nullable=True
    )
    upgrade_order_id: Mapped[str | None] = mapped_column(
        String(32), ForeignKey("payment_orders.id", ondelete="SET NULL"), nullable=True
    )