import uuid
from datetime import datetime

from sqlalchemy import Boolean, DateTime, ForeignKey, String, func
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.database import Base


class Chat(Base):
    __tablename__ = "chats"

    user_id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True), ForeignKey("users.id", ondelete="CASCADE"), nullable=False, index=True
    )
    title: Mapped[str] = mapped_column(String(255), nullable=False, default="New Chat")
    skill_id: Mapped[uuid.UUID | None] = mapped_column(
        UUID(as_uuid=True), ForeignKey("skills.id", ondelete="SET NULL"), nullable=True
    )
    is_archived: Mapped[bool] = mapped_column(Boolean, nullable=False, default=False)
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), server_default=func.now(), onupdate=func.now(), nullable=False
    )

    user: Mapped["User"] = relationship(back_populates="chats")  # noqa: F821
    skill: Mapped["Skill | None"] = relationship()  # noqa: F821
    messages: Mapped[list["Message"]] = relationship(back_populates="chat", cascade="all, delete-orphan")  # noqa: F821