"""Standalone AI assistant chat model.

Persistent conversation history for general IT questions with RAG context.
"""
import uuid
from datetime import datetime, timezone
from typing import Optional, Any

from sqlalchemy import String, DateTime, ForeignKey, Integer, Boolean
from sqlalchemy.orm import Mapped, mapped_column
from sqlalchemy.dialects.postgresql import UUID, JSONB

from app.core.database import Base


class AssistantChat(Base):
    __tablename__ = "assistant_chats"

    id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True), primary_key=True, default=uuid.uuid4
    )
    user_id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True),
        ForeignKey("users.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    account_id: Mapped[uuid.UUID] = mapped_column(
        UUID(as_uuid=True),
        ForeignKey("accounts.id", ondelete="CASCADE"),
        nullable=False,
        index=True,
    )
    title: Mapped[str] = mapped_column(
        String(255), nullable=False, default="New Chat"
    )
    messages: Mapped[list[dict[str, Any]]] = mapped_column(
        JSONB, nullable=False, default=list
    )
    message_count: Mapped[int] = mapped_column(
        Integer, nullable=False, default=0
    )
    total_input_tokens: Mapped[int] = mapped_column(
        Integer, nullable=False, default=0
    )
    total_output_tokens: Mapped[int] = mapped_column(
        Integer, nullable=False, default=0
    )
    pinned: Mapped[bool] = mapped_column(
        Boolean, nullable=False, default=False
    )
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True),
        default=lambda: datetime.now(timezone.utc),
        onupdate=lambda: datetime.now(timezone.utc),
    )
