import os
from neo4j import GraphDatabase
from typing import List, Dict, Any, Optional

class KnowledgeGraphQuerier:
    def __init__(self, uri, auth):
        """
        初始化知识图谱查询器
        
        参数:
            uri: Neo4j数据库URI
            auth: Neo4j认证信息，格式为(username, password)
        """
        self.uri = uri
        self.auth = auth
        self.driver = GraphDatabase.driver(uri, auth=auth)
        # 初始化session属性
        self.session = self.driver.session()
        print(f"已连接到Neo4j数据库: {uri}")
    
    def close(self):
        """关闭数据库连接"""
        if hasattr(self, 'session') and self.session:
            self.session.close()
        if hasattr(self, 'driver') and self.driver:
            self.driver.close()
        print("已关闭Neo4j数据库连接")
    
    def get_node_by_name(self, name: str, node_type: Optional[str] = None) -> List[Dict[str, Any]]:
        """
        通过名称查询节点
        
        参数:
            name: 节点名称
            node_type: 节点类型（可选）
        
        返回:
            节点列表
        """
        with self.driver.session() as session:
            if node_type:
                query = f"""
                MATCH (n:{node_type})
                WHERE n.original_name = $name OR n.display_name = $name
                RETURN n
                """
            else:
                query = """
                MATCH (n)
                WHERE n.original_name = $name OR n.display_name = $name
                RETURN n
                """
            
            result = session.run(query, name=name)
            nodes = []
            for record in result:
                node = record["n"]
                nodes.append(dict(node))
            
            return nodes
    
    def get_related_nodes(self, node_name: str, relationship_type: Optional[str] = None, 
                          max_depth: int = 2) -> List[Dict[str, Any]]:
        """
        获取与指定节点相关的节点
        
        参数:
            node_name: 节点名称
            relationship_type: 关系类型（可选）
            max_depth: 最大深度
        
        返回:
            相关节点列表
        """
        with self.driver.session() as session:
            if relationship_type:
                query = f"""
                MATCH (n)-[r:{relationship_type}*1..{max_depth}]-(related)
                WHERE n.original_name = $name OR n.display_name = $name
                RETURN related
                """
            else:
                query = f"""
                MATCH (n)-[r*1..{max_depth}]-(related)
                WHERE n.original_name = $name OR n.display_name = $name
                RETURN related
                """
            
            result = session.run(query, name=node_name)
            related_nodes = []
            for record in result:
                node = record["related"]
                related_nodes.append(dict(node))
            
            return related_nodes
    
    def search_by_keyword(self, keyword: str) -> List[Dict[str, Any]]:
        """
        通过关键词搜索知识图谱
        
        参数:
            keyword: 搜索关键词
        
        返回:
            匹配的节点列表
        """
        # 使用简化的查询，不包含路径查询
        query = """
        MATCH (n)
        WHERE n.name CONTAINS $keyword 
        OR n.display_name CONTAINS $keyword 
        OR n.original_name CONTAINS $keyword 
        OR n.描述 CONTAINS $keyword
        RETURN n
        LIMIT 50
        """
        
        result = self.session.run(query, keyword=keyword)
        nodes = []
        
        for record in result:
            node = dict(record["n"])
            node["labels"] = list(record["n"].labels)
            nodes.append(node)
        
        return nodes
    
    def get_path_between_nodes(self, start_name: str, end_name: str) -> List[List[Dict[str, Any]]]:
        """
        获取两个节点之间的路径
        
        参数:
            start_name: 起始节点名称
            end_name: 结束节点名称
        
        返回:
            路径列表，每个路径是节点字典的列表
        """
        with self.driver.session() as session:
            query = """
            MATCH p = shortestPath((a)-[*]-(b))
            WHERE (a.original_name = $start_name OR a.display_name = $start_name)
            AND (b.original_name = $end_name OR b.display_name = $end_name)
            RETURN p
            """
            
            result = session.run(query, start_name=start_name, end_name=end_name)
            paths = []
            for record in result:
                path = record["p"]
                path_nodes = []
                for node in path.nodes:
                    path_nodes.append(dict(node))
                paths.append(path_nodes)
            
            return paths
    
    def get_function_details(self, function_name: str) -> Dict[str, Any]:
        """
        获取功能详情
        
        参数:
            function_name: 功能名称
        
        返回:
            功能详情字典，包含功能描述和路径
        """
        with self.driver.session() as session:
            query = """
            MATCH (n:功能名称 {original_name: $name})
            RETURN n
            """
            
            result = session.run(query, name=function_name)
            record = result.single()
            if record:
                node = dict(record["n"])
                
                # 获取功能的完整路径
                path_query = """
                MATCH p = (root:软件)-[*]->(func:功能名称 {original_name: $name})
                RETURN p
                """
                path_result = session.run(path_query, name=function_name)
                path_record = path_result.single()
                
                if path_record:
                    path = path_record["p"]
                    node_path = []
                    for path_node in path.nodes:
                        node_path.append(dict(path_node).get("original_name", ""))
                    
                    node["path"] = " > ".join(filter(None, node_path))
                
                return node
            
            return {}