# -*- coding: utf-8 -*-
"""相似片段检索接口。"""

from typing import List, Optional

from pydantic import BaseModel, Field
from fastapi import APIRouter, HTTPException
from starlette.concurrency import run_in_threadpool
from foundation.observability.logger.loggering import write_logger as logger
from foundation.infrastructure.tracing import TraceContext, auto_trace
from core.construction_write.component.similar_fragment_service import (
    CHILD_COLLECTION,
    PARENT_COLLECTION,
    search_similar_fragments,
)

# ==================== 路由 ====================

similar_fragment_router = APIRouter(prefix="/sgbx", tags=["施工方案编写"])

# ==================== 数据模型 ====================


class SimilarFragmentSearchRequest(BaseModel):
    title_level_1: Optional[str] = Field(None, description="一级标题展示文本", example="施工工艺技术")
    title_level_2: Optional[str] = Field(None, description="二级标题展示文本", example="主要施工方法概述")
    chapter_level_1: str = Field(..., description="一级章节类型，需与向量库字段匹配", example="technology")
    chapter_level_2: str = Field(..., description="二级章节类型，需与向量库字段匹配", example="MethodsOverview")
    chapter_id: str = Field(..., description="当前章节ID（原样回传）")
    project_id: str = Field(..., description="方案ID（原样回传）")
    sgbx_code: Optional[str] = Field(None, description="施工编写章节编码")
    search_text: str = Field(..., description="用户输入的检索信息")

    class Config:
        extra = "ignore"


class SimilarFragmentItem(BaseModel):
    chapter_level_1: str = Field(..., description="一级标题")
    chapter_level_2: str = Field(..., description="二级标题")
    chapter_id: str = Field(..., description="请求传入的章节ID，原样回传")
    project_id: str = Field(..., description="请求传入的方案ID，原样回传")
    text: str = Field(..., description="相似片段内容")
    file_name: str = Field(..., description="文件名称")
    similarity_percent: float = Field(..., description="相似度百分比", ge=0.0, le=100.0)


class SimilarFragmentSearchResponse(BaseModel):
    code: int
    message: str
    data: List[SimilarFragmentItem] = Field(default_factory=list)


# ==================== API 路由 ====================


@similar_fragment_router.post("/similar_fragment_search", response_model=SimilarFragmentSearchResponse)
@auto_trace(generate_if_missing=True)
async def similar_fragment_search(request: SimilarFragmentSearchRequest):
    """
    相似片段检索接口

    根据用户输入的一级/二级标题和检索信息，从知识库向量表中检索出最相关的相似片段。

    Args:
        request: 检索请求，包含一级标题、二级标题、章节ID、方案ID、检索文本

    Returns:
        相似片段列表，包含内容、文件名、相似度百分比
    """
    trace_id = TraceContext.get_trace_id()
    logger.info(
        f"[{trace_id}] 相似片段检索: title_level_1={request.title_level_1}, "
        f"title_level_2={request.title_level_2}, chapter_level_1={request.chapter_level_1}, "
        f"chapter_level_2={request.chapter_level_2}, 检索文本={request.search_text[:50]}..."
    )

    # 参数校验
    if not request.chapter_level_1.strip() or not request.chapter_level_2.strip():
        return SimilarFragmentSearchResponse(
            code=400,
            message="章节类型 chapter_level_1 和 chapter_level_2 不能为空",
            data=[]
        )

    if not request.search_text.strip():
        return SimilarFragmentSearchResponse(
            code=400,
            message="检索信息不能为空",
            data=[]
        )

    if len(request.search_text.strip()) < 3:
        return SimilarFragmentSearchResponse(
            code=400,
            message="检索信息过短，请输入至少3个字符",
            data=[]
        )

    try:
        raw_results = await run_in_threadpool(
            search_similar_fragments,
            level1=request.chapter_level_1,
            level2=request.chapter_level_2,
            search_text=request.search_text,
            top_k=5,
        )

        # 组装返回
        items = []
        for r in raw_results:
            similarity_percent = round(r["similarity"] * 100, 2)
            items.append(SimilarFragmentItem(
                chapter_level_1=r["chapter_level_1"],
                chapter_level_2=r["chapter_level_2"],
                chapter_id=request.chapter_id,
                project_id=request.project_id,
                text=r["text"],
                file_name=r["file_name"],
                similarity_percent=similarity_percent,
            ))

        return SimilarFragmentSearchResponse(
            code=200,
            message="success",
            data=items
        )

    except Exception as e:
        logger.error(f"[{trace_id}] 相似片段检索异常: {e}", exc_info=True)
        raise HTTPException(
            status_code=500,
            detail=f"相似片段检索失败: {str(e)}"
        )


@similar_fragment_router.get("/similar_fragment_search_health")
async def health_check():
    """相似片段检索健康检查"""
    return {
        "status": "healthy",
        "vector_db": "Milvus (lq_db)",
        "child_collection": CHILD_COLLECTION,
        "parent_collection": PARENT_COLLECTION,
    }