"""菌群知识库加载器: 从 Java 后端同步文章到 ChromaDB"""
import logging
import httpx
from langchain_chroma import Chroma
from langchain_core.documents import Document
from app.config import settings
from app.rag.embeddings import get_embeddings
from app.rag.splitter import get_knowledge_splitter

logger = logging.getLogger(__name__)
COLLECTION_NAME = "microbiome_kb"


class MicrobiomeLoader:

    def __init__(self):
        self.embeddings = get_embeddings()
        self.vectorstore = Chroma(
            collection_name=COLLECTION_NAME,
            embedding_function=self.embeddings,
            persist_directory=settings.chroma_db_path,
        )
        self.splitter = get_knowledge_splitter()

    async def fetch_articles(self, keyword=None) -> list[dict]:
        client = httpx.AsyncClient(base_url=settings.java_base_url, timeout=120)
        try:
            if keyword:
                resp = await client.post("/api/microbiome/article/search", json={"keyword": keyword})
                data = resp.json()
                if data.get("code") == 200:
                    return data.get("data", [])
            else:
                page = 1
                size = 50
                records = []
                while True:
                    resp = await client.post("/api/microbiome/article/list",
                                             json={"page": page, "size": size, "keyword": "", "category": ""})
                    data = resp.json()
                    if data.get("code") != 200:
                        break
                    body = data.get("data", {}) or {}
                    items = body.get("records", []) or []
                    records.extend(items)
                    total = body.get("total", 0)
                    if page * size >= int(total or 0) or not items:
                        break
                    page += 1
                return records
        except Exception as e:
            logger.warning("获取菌群文章失败: %s", e)
        finally:
            await client.aclose()
        return []

    async def fetch_article(self, article_id: int) -> dict | None:
        client = httpx.AsyncClient(base_url=settings.java_base_url, timeout=120)
        try:
            resp = await client.post("/api/microbiome/article/detail", json={"id": article_id})
            data = resp.json()
            if data.get("code") == 200:
                return data.get("data")
        except Exception as e:
            logger.warning("获取菌群文章详情失败: %s", e)
        finally:
            await client.aclose()
        return None

    def _build_chunks(self, article: dict) -> list[Document]:
        content = f"{article.get('title', '')}\n\n{article.get('content', '')}"
        split_texts = self.splitter.split_text(content)
        category = article.get("category", "科普")
        tags = article.get("tags", "")
        docs = []
        for i, text in enumerate(split_texts):
            docs.append(Document(
                page_content=text,
                metadata={
                    "id": f"article_{article['id']}_{i}",
                    "postId": str(article["id"]),
                    "title": article.get("title", ""),
                    "category": category,
                    "tags": tags,
                    "source_url": article.get("sourceUrl", ""),
                    "pub_date": article.get("pubDate", ""),
                    "chunk_index": i,
                    "chunk_total": len(split_texts),
                    "source": "microbiome_kb",
                },
            ))
        return docs

    async def sync_all(self):
        articles = await self.fetch_articles()
        if not articles:
            logger.info("菌群知识库同步: 无文章")
            return
        try:
            existing_ids = self.vectorstore.get()["ids"]
            if existing_ids:
                self.vectorstore.delete(existing_ids)
        except Exception:
            pass
        all_docs = []
        for article in articles:
            all_docs.extend(self._build_chunks(article))
        for i in range(0, len(all_docs), 200):
            await self.vectorstore.aadd_documents(all_docs[i:i + 200])
        logger.info("菌群知识库全量同步完成: %d 篇文章, %d 个chunk", len(articles), len(all_docs))

    async def sync_one(self, article_id: int):
        article = await self.fetch_article(article_id)
        if not article:
            logger.warning("菌群文章不存在: %d", article_id)
            return
        prefix = f"article_{article_id}_"
        try:
            existing = self.vectorstore.get()
            ids_to_delete = [i for i in existing["ids"] if i.startswith(prefix)]
            if ids_to_delete:
                self.vectorstore.delete(ids_to_delete)
        except Exception:
            pass
        docs = self._build_chunks(article)
        if docs:
            await self.vectorstore.aadd_documents(docs)
        logger.info("菌群文章同步完成: %d (%s), %d 个chunk",
                    article_id, article.get("title", ""), len(docs))