from __future__ import annotations

from datetime import datetime
from typing import Any

from sqlalchemy import DateTime, ForeignKey, JSON, String, UniqueConstraint, func
from sqlalchemy.orm import Mapped, mapped_column

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


class ClassSessionProgress(Base):
    """Per-user, per-class tuition class progress (the 11-step guided class).

    One row per (user, class_session_id). The resumable class state is stored as
    a JSON blob so the step shape can evolve freely.
    """

    __tablename__ = "class_session_progress"
    __table_args__ = (
        UniqueConstraint("user_id", "class_session_id", name="uq_class_session_user_session"),
    )

    id: Mapped[str] = mapped_column(
        String(40),
        primary_key=True,
        default=lambda: prefixed_id("cprog"),
    )
    user_id: Mapped[str] = mapped_column(
        String(40),
        ForeignKey("users.id"),
        index=True,
        nullable=False,
    )
    class_session_id: Mapped[str] = mapped_column(String(200), nullable=False)
    data: Mapped[dict[str, Any]] = mapped_column(JSON, default=dict, 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,
    )