from __future__ import annotations

from datetime import datetime

from sqlalchemy import DateTime, ForeignKey, Index, Integer, String, func
from sqlalchemy.orm import Mapped, mapped_column

from app.core.database import Base
from app.utils.ids import prefixed_id


class UserPlan(Base):
    __tablename__ = "user_plans"

    id: Mapped[str] = mapped_column(
        String(40),
        primary_key=True,
        default=lambda: prefixed_id("plan"),
    )
    user_id: Mapped[str] = mapped_column(
        String(40),
        ForeignKey("users.id"),
        unique=True,
        index=True,
        nullable=False,
    )
    selected_plan: Mapped[str] = mapped_column(
        String(60),
        default="free",
        nullable=False,
    )
    status: Mapped[str] = mapped_column(
        String(40),
        default="active",
        nullable=False,
    )
    trial_started_at: Mapped[datetime | None] = mapped_column(
        DateTime(timezone=True),
        nullable=True,
    )
    trial_ends_at: Mapped[datetime | None] = mapped_column(
        DateTime(timezone=True),
        nullable=True,
    )
    # Tracks the start of the current billing period for monthly reset logic
    period_start: Mapped[datetime | None] = mapped_column(
        DateTime(timezone=True),
        nullable=True,
    )
    monthly_video_limit: Mapped[int] = mapped_column(Integer, default=3, nullable=False)
    monthly_video_used: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    monthly_generation_limit: Mapped[int] = mapped_column(Integer, default=30, nullable=False)
    monthly_generation_used: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        server_default=func.now(),
        nullable=False,
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        server_default=func.now(),
        onupdate=func.now(),
        nullable=False,
    )

    # Supabase/Postgres best practices: explicit indexes for common query patterns
    # (user lookups already have unique+index on user_id; add for plan filtering + period resets)
    __table_args__ = (
        Index("ix_user_plans_selected_plan_status", "selected_plan", "status"),
        Index("ix_user_plans_period_start", "period_start"),
    )