from fastapi import APIRouter, Depends
from sqlalchemy.orm import Session
from starlette.responses import StreamingResponse

from app.core.response import ApiResponse, ok
from app.core.user_context import UserContext, get_user_context
from app.db.session import get_db
from app.schemas.learning_assistant import LearningAssistantChatRequest, LearningAssistantChatResponse
from app.services.learning_assistant_service import LearningAssistantService

router = APIRouter()


@router.post("/chat", response_model=ApiResponse[LearningAssistantChatResponse], include_in_schema=False)
async def learning_assistant_chat(
    payload: LearningAssistantChatRequest,
    ctx: UserContext = Depends(get_user_context),
    db: Session = Depends(get_db),
):
    """AI 学习助手调试接口：非流式返回回答，正式前端联调使用流式接口。"""
    result = await LearningAssistantService(db).chat(ctx, payload)
    db.commit()
    return ok(result)


@router.post("/chat/stream", response_class=StreamingResponse)
async def learning_assistant_stream_chat(
    payload: LearningAssistantChatRequest,
    ctx: UserContext = Depends(get_user_context),
    db: Session = Depends(get_db),
):
    """AI 学习助手流式问答：返回 retrieval_done、answer_delta、answer_done 事件。"""
    stream = LearningAssistantService(db).stream_chat(ctx, payload)
    db.commit()
    return StreamingResponse(
        stream,
        media_type="text/event-stream",
        headers={"Cache-Control": "no-cache", "Connection": "keep-alive", "X-Accel-Buffering": "no"},
    )