import os
import chromadb
from chromadb.config import Settings
from typing import List, Dict, Optional
from config import Config
from core.openai_client import OpenAIClient

class MemoryManager:
    """向量记忆管理器 - 存储和检索角色相关的文本片段"""
    
    def __init__(self, character_name: str):
        self.character_name = character_name
        self.client = OpenAIClient.get_client()
        
        # 创建向量数据库目录
        os.makedirs(Config.VECTOR_DB_PATH, exist_ok=True)
        
        try:
            self.chroma_client = chromadb.Client(Settings(
                persist_directory=Config.VECTOR_DB_PATH,
                anonymized_telemetry=False
            ))
        except:
            # 如果上面的方式失败，尝试使用 PersistentClient
            self.chroma_client = chromadb.PersistentClient(
                path=Config.VECTOR_DB_PATH
            )
        
        # 为每个角色创建独立的集合
        collection_name = f"char_{character_name.replace(' ', '_').lower()}"
        collection_name = collection_name[:63]  # ChromaDB 限制集合名长度
        
        try:
            self.collection = self.chroma_client.get_or_create_collection(
                name=collection_name,
                metadata={"character": character_name}
            )
        except Exception as e:
            print(f"创建集合时出错: {e}")
            # 如果创建失败，尝试使用更简单的名称
            collection_name = f"char_{hash(character_name) % 10000}"
            self.collection = self.chroma_client.get_or_create_collection(
                name=collection_name,
                metadata={"character": character_name}
            )
    
    def add_text_chunks(self, chunks: List[Dict], character_chunks: List[int]):
        """添加与角色相关的文本块
        
        Args:
            chunks: 所有文本块
            character_chunks: 角色出现的文本块ID列表
        """
        
        documents = []
        metadatas = []
        ids = []
        
        for chunk_id in character_chunks:
            if chunk_id < len(chunks):
                chunk = chunks[chunk_id]
                documents.append(chunk['text'])
                metadatas.append({
                    'chunk_id': chunk_id,
                    'position': chunk['start']
                })
                ids.append(f"chunk_{chunk_id}")
        
        if documents:
            try:
                # 批量添加，避免一次性添加太多
                batch_size = 100
                for i in range(0, len(documents), batch_size):
                    batch_docs = documents[i:i+batch_size]
                    batch_metas = metadatas[i:i+batch_size]
                    batch_ids = ids[i:i+batch_size]
                    
                    self.collection.add(
                        documents=batch_docs,
                        metadatas=batch_metas,
                        ids=batch_ids
                    )
                
                print(f"已为 {self.character_name} 添加 {len(documents)} 个文本块到向量库")
            except Exception as e:
                print(f"添加文本块到向量库失败: {e}")
                print("将继续运行，但不使用记忆功能")
    
    def search_relevant_context(self, query: str, n_results: int = None) -> List[str]:
        """检索与查询相关的上下文
        
        Args:
            query: 查询文本
            n_results: 返回结果数量
            
        Returns:
            相关文本片段列表
        """
        
        n_results = n_results or Config.MAX_MEMORY_RETRIEVAL
        
        try:
            collection_count = self.collection.count()
            if collection_count == 0:
                return []
            
            actual_n_results = min(n_results, collection_count)
            
            results = self.collection.query(
                query_texts=[query],
                n_results=actual_n_results
            )
            
            if results and results['documents']:
                return results['documents'][0]
            return []
        
        except Exception as e:
            print(f"检索失败: {e}")
            return []
    
    def get_embedding(self, text: str) -> List[float]:
        """获取文本嵌入向量
        
        Args:
            text: 输入文本
            
        Returns:
            嵌入向量
        """
        try:
            response = self.client.embeddings.create(
                model=Config.EMBEDDING_MODEL,
                input=text
            )
            return response.data[0].embedding
        except Exception as e:
            print(f"获取嵌入失败: {e}")
            return []
    
    def get_statistics(self) -> Dict:
        """获取记忆库统计信息
        
        Returns:
            统计信息字典
        """
        try:
            count = self.collection.count()
            return {
                'character': self.character_name,
                'chunk_count': count,
                'collection_name': self.collection.name
            }
        except:
            return {
                'character': self.character_name,
                'chunk_count': 0,
                'collection_name': 'unknown'
            }
    
    def clear(self):
        """清空记忆库"""
        try:
            # 删除集合
            self.chroma_client.delete_collection(self.collection.name)
            print(f"已清空 {self.character_name} 的记忆库")
        except Exception as e:
            print(f"清空记忆库失败: {e}")