"""
Elasticsearch 搜索管理
"""
from typing import List, Dict, Any, Optional
from utils.es.base import ESConnection


class SearchManager:
    """
    Elasticsearch 搜索管理器
    负责：
    - 全文检索
    - 向量相似度检索（k-NN）
    - 混合检索（文本+向量）
    - 高亮显示
    """
    
    def __init__(self, es_connection: Optional[ESConnection] = None):
        """
        初始化搜索管理器
        
        Args:
            es_connection: ES 连接实例，可选
        """
        self.es_conn = es_connection or ESConnection()
        self.es = self.es_conn.get_client()
    
    def search(self, index_name: str, query: Dict[str, Any], size: int = 10, from_: int = 0, 
               fields: List[str] = None, highlight: Dict[str, Any] = None) -> Dict[str, Any]:
        """
        搜索文档
        
        Args:
            index_name: 索引名称
            query: 查询条件
            size: 返回结果数量
            from_: 起始位置
            fields: 要返回的字段列表，可选
            highlight: 高亮配置，可选
        
        Returns:
            Dict: 搜索结果
        """
        try:
            body = {
                "query": query,
                "size": size,
                "from": from_
            }
            
            if fields:
                body["_source"] = fields
            
            if highlight:
                body["highlight"] = highlight
            
            result = self.es.search(index=index_name, body=body)
            return result
        except Exception as e:
            print(f"搜索失败: {e}")
            return {"hits": {"total": 0, "hits": []}}
    
    def hybrid_search(self, index_name: str, text_query: str, vector_field: str, vector: List[float], 
                     size: int = 10, from_: int = 0, fields: List[str] = None, 
                     text_weight: float = 0.5, vector_weight: float = 0.5) -> Dict[str, Any]:
        """
        混合检索：向量相似度检索 + 全文检索
        
        Args:
            index_name: 索引名称
            text_query: 文本查询语句
            vector_field: 向量字段名
            vector: 检索向量
            size: 返回结果数量
            from_: 起始位置
            fields: 要返回的字段列表，可选
            text_weight: 文本检索权重
            vector_weight: 向量检索权重
        
        Returns:
            Dict: 搜索结果
        """
        try:
            # 构建混合检索查询
            query = {
                "bool": {
                    "should": [
                        {
                            "query_string": {
                                "query": text_query,
                                "default_operator": "OR",
                                "boost": text_weight
                            }
                        },
                        {
                            "script_score": {
                                "query": {
                                    "match_all": {}
                                },
                                "script": {
                                    "source": "cosineSimilarity(params.query_vector, doc[params.vector_field]) + 1.0",
                                    "params": {
                                        "query_vector": vector,
                                        "vector_field": vector_field
                                    }
                                },
                                "boost": vector_weight
                            }
                        }
                    ]
                }
            }
            
            body = {
                "query": query,
                "size": size,
                "from": from_
            }
            
            if fields:
                body["_source"] = fields
            
            result = self.es.search(index=index_name, body=body)
            return result
        except Exception as e:
            print(f"混合检索失败: {e}")
            return {"hits": {"total": 0, "hits": []}}
    
    def knn_search(self, index_name: str, vector_field: str, vector: List[float], 
                  k: int = 10, filter_query: Dict[str, Any] = None) -> Dict[str, Any]:
        """
        向量相似度检索（k-NN）
        
        Args:
            index_name: 索引名称
            vector_field: 向量字段名
            vector: 检索向量
            k: 返回结果数量
            filter_query: 过滤条件，可选
        
        Returns:
            Dict: 搜索结果
        """
        try:
            knn = {
                "field": vector_field,
                "query_vector": vector,
                "k": k,
                "num_candidates": k * 10
            }
            
            if filter_query:
                knn["filter"] = filter_query
            
            body = {
                "knn": knn
            }
            
            result = self.es.search(index=index_name, body=body)
            return result
        except Exception as e:
            print(f"向量检索失败: {e}")
            return {"hits": {"total": 0, "hits": []}}
    
    def match_search(self, index_name: str, field: str, value: str, size: int = 10, 
                     fields: List[str] = None) -> Dict[str, Any]:
        """
        简单匹配搜索
        
        Args:
            index_name: 索引名称
            field: 字段名
            value: 匹配值
            size: 返回结果数量
            fields: 要返回的字段列表，可选
        
        Returns:
            Dict: 搜索结果
        """
        query = {
            "match": {
                field: value
            }
        }
        return self.search(index_name, query, size=size, fields=fields)
    
    def match_all(self, index_name: str, size: int = 10, fields: List[str] = None) -> Dict[str, Any]:
        """
        匹配所有文档
        
        Args:
            index_name: 索引名称
            size: 返回结果数量
            fields: 要返回的字段列表，可选
        
        Returns:
            Dict: 搜索结果
        """
        query = {
            "match_all": {}
        }
        return self.search(index_name, query, size=size, fields=fields)