import uuid
from fastapi import APIRouter
from app.models.chat import ChatRequest, ChatResponse, SourceInfo
from app.graphs.chat_graph import create_chat_graph

router = APIRouter(prefix="/api/v1", tags=["chat"])

_graph = None


def get_graph():
    global _graph
    if _graph is None:
        _graph = create_chat_graph()
    return _graph


@router.post("/chat", response_model=ChatResponse)
async def chat(req: ChatRequest):
    """家庭聊天: 意图分类→上下文→LLM→记忆"""
    trace_id = str(uuid.uuid4())
    graph = get_graph()

    initial_state = {
        "query": req.query,
        "user_id": req.user_id,
        "conversation_id": req.conversation_id,
        "child_id": req.context.child_id if req.context else None,
        "intent": None,
        "context": None,
        "messages": None,
        "answer": None,
        "tasks": [],
        "sources": [],
    }

    config = {
        "configurable": {"thread_id": req.conversation_id or str(req.user_id)},
    }

    result = await graph.ainvoke(initial_state, config)

    sources = []
    for s in result.get("sources", []):
        sources.append(SourceInfo(
            type=s.get("type", "tool"),
            title=s.get("name", ""),
        ))

    conv_id = req.conversation_id or f"conv_{req.user_id}_{__import__('time').time()}"

    return ChatResponse(
        answer=result.get("answer", ""),
        conversation_id=conv_id,
        sources=sources,
        tasks=result.get("tasks", []),
        trace_id=trace_id,
    )