"""会话列表与消息：从 DB 读取，需登录。"""
from fastapi import APIRouter, Depends
from sqlalchemy import select
from sqlalchemy.ext.asyncio import AsyncSession

from app.database import get_db
from app.deps import get_current_user_id
from app.logging_config import get_trace_id
from app.models import ChatSession, Message

router = APIRouter()


def _session_row(s: ChatSession) -> dict:
    return {
        "id": s.id,
        "external_user_id": s.external_user_id,
        "external_name": s.external_name,
        "status": s.status,
        "created_at": s.created_at.isoformat() if s.created_at else None,
    }


def _message_row(m: Message) -> dict:
    return {
        "id": m.id,
        "role": m.role,
        "content": m.content,
        "created_at": m.created_at.isoformat() if m.created_at else None,
    }


@router.get("")
async def list_sessions(
    db: AsyncSession = Depends(get_db),
    _user: str = Depends(get_current_user_id),
):
    """会话列表。"""
    r = await db.execute(select(ChatSession).order_by(ChatSession.updated_at.desc()))
    rows = r.scalars().all()
    return {"code": 0, "message": "ok", "data": [_session_row(s) for s in rows], "trace_id": get_trace_id()}


@router.get("/{session_id}/messages")
async def list_messages(
    session_id: int,
    db: AsyncSession = Depends(get_db),
    _user: str = Depends(get_current_user_id),
):
    """某会话消息列表。"""
    r = await db.execute(select(Message).where(Message.session_id == session_id).order_by(Message.id))
    rows = r.scalars().all()
    return {"code": 0, "message": "ok", "data": [_message_row(m) for m in rows], "trace_id": get_trace_id()}