"""
Qdrant 向量数据库包装器。
"""

import logging
import os
import time
from typing import List, Optional, Dict, Any

from langchain_core.documents import Document
from langchain_qdrant import QdrantVectorStore as LangchainQdrantVS
from qdrant_client import QdrantClient
from qdrant_client.http.models import Distance, VectorParams
from httpx import RemoteProtocolError
from qdrant_client.http.exceptions import ResponseHandlingException
from rag_core.client import create_qdrant_client

logger = logging.getLogger(__name__)

QDRANT_URL = os.getenv("QDRANT_URL", "http://127.0.0.1:6333")
QDRANT_API_KEY = os.getenv("QDRANT_API_KEY")


class QdrantVectorStore:
    """Qdrant 向量数据库操作包装器。"""

    def __init__(
        self,
        collection_name: str,
        embeddings: Optional[Any] = None,
    ):
        self.collection_name = collection_name
        self._client: Optional[QdrantClient] = None
        self._connection_attempts = 0
        self._last_connection_time: Optional[float] = None

        if embeddings is None:
            from rag_core.embedders import LlamaCppEmbedder
            embedder = LlamaCppEmbedder()
            self.embeddings = embedder.as_langchain_embeddings()
        else:
            self.embeddings = embeddings

        self.create_collection()

        self.vector_store = LangchainQdrantVS(
            client=self.get_client(),
            collection_name=self.collection_name,
            embedding=self.embeddings,
        )

    def get_client(self) -> QdrantClient:
        if self._client is None:
            self._client = create_qdrant_client(timeout=300)
            self._connection_attempts += 1
            self._last_connection_time = time.time()
            logger.debug("Qdrant 客户端已创建 (第 %d 次连接)", self._connection_attempts)
        return self._client

    def refresh_client(self):
        """关闭旧连接，创建新连接。"""
        if self._client is not None:
            try:
                self._client.close()
                logger.debug("Qdrant 旧连接已关闭")
            except Exception as e:
                logger.warning("关闭 Qdrant 连接时出现异常: %s", e)
            finally:
                self._client = None
                self._last_connection_time = None

    def check_connection_health(self) -> bool:
        """检查连接健康状态，如果连接已失效则自动重建。"""
        if self._client is None:
            logger.info("Qdrant 客户端未初始化，将创建新连接")
            return False
        
        try:
            client = self.get_client()
            client.get_collections()
            logger.debug("Qdrant 连接健康检查通过")
            return True
        except (RemoteProtocolError, ConnectionError, OSError, ResponseHandlingException) as e:
            logger.warning("Qdrant 连接健康检查失败: %s", e)
            self.refresh_client()
            return False

    def get_connection_stats(self) -> Dict[str, Any]:
        """获取连接统计信息。"""
        return {
            "connection_attempts": self._connection_attempts,
            "last_connection_time": self._last_connection_time,
            "client_initialized": self._client is not None,
        }

    def create_collection(self, vector_size: Optional[int] = None, force_recreate: bool = False):
        """创建集合，设置合适的向量维度。"""
        if vector_size is None:
            from rag_core.embedders import LlamaCppEmbedder
            embedder = LlamaCppEmbedder()
            vector_size = embedder.get_embedding_dimension()

        max_retries = 3
        base_delay = 2
        for attempt in range(max_retries):
            try:
                client = self.get_client()
                collections = client.get_collections().collections
                exists = any(c.name == self.collection_name for c in collections)

                if exists and force_recreate:
                    client.delete_collection(self.collection_name)
                    exists = False

                if not exists:
                    client.create_collection(
                        collection_name=self.collection_name,
                        vectors_config=VectorParams(size=vector_size, distance=Distance.COSINE),
                    )
                    logger.info("集合 '%s' 已创建（维度=%d）", self.collection_name, vector_size)
                else:
                    logger.info("集合 '%s' 已存在", self.collection_name)
                return
            except (RemoteProtocolError, ConnectionError, OSError, ResponseHandlingException) as e:
                if attempt == max_retries - 1:
                    logger.error("创建集合 '%s' 重试 %d 次后仍然失败: %s", self.collection_name, max_retries, e)
                    raise
                wait_time = base_delay * (2 ** attempt)
                error_type = type(e).__name__
                logger.warning(
                    "创建集合 '%s' 遇到网络异常 [%s]，%d秒后重试 (%d/%d): %s",
                    self.collection_name, error_type, wait_time, attempt + 1, max_retries, e
                )
                self.refresh_client()
                logger.debug("已刷新 Qdrant 客户端连接")
                time.sleep(wait_time)

    def add_documents(self, documents: List[Document], batch_size: int = 100):
        """将文档添加到向量数据库。"""
        if not documents:
            return []
        self.create_collection()
        ids = self.vector_store.add_documents(documents, batch_size=batch_size)
        logger.info("已向 '%s' 添加 %d 个文档", self.collection_name, len(ids))
        return ids

    def similarity_search(self, query: str, k: int = 5) -> List[Document]:
        return self.vector_store.similarity_search(query, k=k)

    def similarity_search_with_score(self, query: str, k: int = 5) -> List[tuple[Document, float]]:
        return self.vector_store.similarity_search_with_score(query, k=k)

    def delete_collection(self):
        self.get_client().delete_collection(self.collection_name)
        logger.info("集合 '%s' 已删除", self.collection_name)

    def get_collection_info(self) -> Dict[str, Any]:
        info = self.get_client().get_collection(self.collection_name)
        vectors_config = info.config.params.vectors
        if isinstance(vectors_config, dict):
            first_config = next(iter(vectors_config.values()), None)
            vector_size = first_config.size if first_config else 0
        else:
            vector_size = vectors_config.size if vectors_config else 0
        return {
            "name": self.collection_name,
            "vectors_count": info.points_count or 0,
            "status": info.status,
            "vector_size": vector_size,
        }

    def as_langchain_vectorstore(self):
        return self.vector_store

    def get_langchain_vectorstore(self):
        """返回 LangChain Qdrant 向量存储对象（别名）"""
        return self.vector_store

    def get_qdrant_client(self):
        """返回原生 Qdrant 客户端（如需手动管理 collection）"""
        return self.get_client()