"""Define API routes for rag."""

from __future__ import annotations

import json
from typing import AsyncGenerator

from fastapi import APIRouter, Depends
from fastapi.responses import StreamingResponse

from app.api.dependencies.auth import get_current_user
from app.config.settings import settings
from app.domain.auth.models import UserClaims
from app.schemas.rag import RagChatRequest, QuickQuestionsResponse, QuickQuestion
from app.shared.async_utils import iter_in_thread
from app.shared.bootstrap import get_agent_conversation_service


router = APIRouter(prefix="/rag", tags=["RAG问答"])

_DEFAULT_QUICK_QUESTIONS = [
    {"id": "1", "question": "请总结最新入库法规对电池安全的核心要求", "category": "法规解读"},
    {"id": "2", "question": "我上传的制度文档与新能源法规有哪些潜在冲突？", "category": "差距分析"},
    {"id": "3", "question": "请给出法规依据，并按条款列出整改建议", "category": "整改建议"},
    {"id": "4", "question": "请解释 UN-ECE 与 GB 标准在网络安全方面的差异", "category": "标准对比"},
    {"id": "5", "question": "IATF 16949 对供应商质量管理有哪些强制要求？", "category": "法规解读"},
    {"id": "6", "question": "ISO 45001 与 AQ 标准在职业健康安全方面的主要差异是什么？", "category": "标准对比"},
]


@router.post("/chat")
async def rag_chat(
    request: RagChatRequest,
    current_user: UserClaims = Depends(get_current_user),
):
    """Stream RAG Q&A using the real agent service."""
    session_id, event_stream = get_agent_conversation_service().stream_chat(
        query=request.query,
        session_id=request.session_id,
        filters=request.filters,
        top_k=request.top_k or settings.rag_top_k,
    )

    async def generate() -> AsyncGenerator[str, None]:
        """Translate agent SSE events to rag format."""
        yield (
            "event: message\n"
            f"data: {json.dumps({'type': 'session', 'session_id': session_id}, ensure_ascii=False)}\n\n"
        )
        async for event in iter_in_thread(event_stream):
            event_type = event.get("event", "")
            data = event.get("data", "")
            if event_type == "sources":
                docs = [
                    {
                        "id": str(s.get("chunk_id") or s.get("doc_id") or idx + 1),
                        "score": s.get("score", 0),
                        "preview": s.get("text", s.get("content", ""))[:200],
                        "doc_name": s.get("doc_title", s.get("doc_name", "")),
                        "clause": s.get("section_title", "法规片段"),
                        "doc_id": s.get("doc_id"),
                        "download_url": (
                            f"/api/v1/documents/download/{s['doc_id']}" if s.get("doc_id") else None
                        ),
                    }
                    for idx, s in enumerate(data if isinstance(data, list) else [])
                ]
                yield (
                    "event: message\n"
                    f"data: {json.dumps({'type': 'retrieved', 'docs': docs}, ensure_ascii=False)}\n\n"
                )
            elif event_type == "content":
                if data:
                    yield (
                        "event: message\n"
                        f"data: {json.dumps({'type': 'chunk', 'text': data}, ensure_ascii=False)}\n\n"
                    )
            elif event_type == "done":
                yield (
                    "event: message\n"
                    f"data: {json.dumps({'type': 'done', 'session_id': session_id}, ensure_ascii=False)}\n\n"
                )
            elif event_type == "status":
                yield (
                    "event: message\n"
                    f"data: {json.dumps({'type': 'status', 'text': data}, ensure_ascii=False)}\n\n"
                )
            elif event_type == "error":
                yield (
                    "event: message\n"
                    f"data: {json.dumps({'type': 'error', 'text': str(data)}, ensure_ascii=False)}\n\n"
                )

    return StreamingResponse(
        generate(),
        media_type="text/event-stream",
        headers={"Cache-Control": "no-cache", "Connection": "keep-alive", "X-Accel-Buffering": "no"},
    )


@router.get("/quick-questions", response_model=QuickQuestionsResponse)
async def get_quick_questions():
    """Return configurable quick questions from settings or defaults."""
    raw = getattr(settings, "rag_quick_questions", None)
    if raw and isinstance(raw, list):
        questions = [
            QuickQuestion(id=str(i + 1), question=q if isinstance(q, str) else q.get("question", ""), category=q.get("category", "法规问答") if isinstance(q, dict) else "法规问答")
            for i, q in enumerate(raw)
        ]
    else:
        questions = [QuickQuestion(**q) for q in _DEFAULT_QUICK_QUESTIONS]
    return QuickQuestionsResponse(questions=questions)