"""检索 API — /api/search"""
from fastapi import APIRouter, Request, HTTPException, Query
from typing import Optional

from app.services.retriever import Retriever
from app.services.embedding import embed_text
from app.services.history import add_search_history
from app.config import MAX_QUERY_LENGTH

router = APIRouter()


@router.get("/search")
async def search(
    request: Request,
    query: str = Query(..., min_length=1, max_length=MAX_QUERY_LENGTH, description="查询文本"),
    mode: str = Query("semantic", description="检索模式:semantic(语义) / keyword(关键词精确)"),
    category: Optional[str] = Query(None, description="法规类别过滤"),
    province: Optional[str] = Query(None, description="省份过滤"),
    city: Optional[str] = Query(None, description="市级过滤"),
    top_k: int = Query(20, ge=1, le=100, description="返回数量"),
    page: int = Query(1, ge=1, description="页码"),
    page_size: int = Query(20, ge=1, le=100, description="每页数量"),
):
    """检索法规条文(语义检索或关键词精确搜索)

    - mode=semantic: 向量化查询 → FAISS 检索 → metadata 过滤(默认)
    - mode=keyword: 按法规名+条号精确匹配,支持"郑州市劳动用工条例 第三十二条"
    """
    trace_id = getattr(request.state, "trace_id", "")

    retriever = Retriever.get_instance()
    if not retriever.is_ready():
        raise HTTPException(status_code=503, detail="索引未加载,请等待或检查索引文件")

    if mode == "keyword":
        # 关键词精确搜索
        results = retriever.keyword_search(
            query=query,
            top_k=top_k * 3 if (category or province or city) else top_k,
            category=category,
            province=province,
            city=city,
        )
    else:
        # 语义检索
        try:
            query_vec = await embed_text(query)
        except Exception as e:
            raise HTTPException(
                status_code=503,
                detail=f"embedding 服务不可用: {str(e)}",
            )
        fetch_k = top_k * 3 if (category or province or city) else top_k
        results = retriever.search(
            query_vec=query_vec,
            top_k=fetch_k,
            category=category,
            province=province,
            city=city,
        )

    # 分页
    total = len(results)
    start = (page - 1) * page_size
    end = start + page_size
    page_results = results[start:end]

    # 记录检索历史
    add_search_history(
        query=query,
        category=category,
        province=province,
        city=city,
        result_count=total,
        top_k=top_k,
    )

    return {
        "code": 0,
        "message": "ok",
        "data": {
            "results": page_results,
            "total": total,
            "page": page,
            "page_size": page_size,
        },
        "trace_id": trace_id,
    }