# -*- coding: utf-8 -*-
"""Multi-Query RAG - generate multiple query variants for retrieval."""
from .base import BaseRAG


class MultiQueryRAG(BaseRAG):
    def __init__(self, num_queries=3, **kwargs):
        super().__init__(**kwargs)
        self.num_queries = num_queries

    def _generate_queries(self, query):
        prompt = (
            "请为以下问题生成{}个不同的查询变体，用于提高检索效果。\n\n"
            "原始问题：{}\n\n"
            "查询变体（用换行分隔）：".format(self.num_queries, query)
        )
        response = self._call_llm(prompt)
        return [q.strip() for q in response.strip().split("\n") if q.strip()][:self.num_queries]

    def retrieve(self, query, k=10):
        queries = self._generate_queries(query)
        all_queries = [query] + queries
        
        all_results = {}
        per_query_k = max(k // len(all_queries), 3)
        
        for q in all_queries:
            q_embedding = self.embedding_model.embed_query(q)
            results = self.vector_store.similarity_search(q_embedding, per_query_k)
            for doc, score in results:
                key = self._dedup_key(doc)
                if key not in all_results or score > all_results[key][1]:
                    all_results[key] = (doc, score)
        
        results = list(all_results.values())
        results.sort(key=lambda x: x[1], reverse=True)
        return self._deduplicate_results(results, k)

    def generate(self, query, context):
        prompt = (
            "根据以下多角度查询检索的参考文档，回答问题。\n\n"
            "参考文档：\n{}\n\n"
            "问题：{}\n\n"
            "请详细回答。".format(context, query)
        )
        return self._call_llm(prompt)