# -*- coding: utf-8 -*-
"""Adaptive RAG - adaptively choose retrieval strategy based on query complexity."""
from .base import BaseRAG
from loguru import logger


class AdaptiveRAG(BaseRAG):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)
        self.max_iterations = 3

    def _analyze_query(self, query):
        prompt = (
            "分析以下问题的复杂度。请回答simple或complex或needs_multi_step。\n\n"
            "问题：{}\n\n"
            "回答：".format(query)
        )
        response = self._call_llm(prompt).strip().lower()
        if "complex" in response:
            return "complex"
        elif "multi" in response:
            return "multi_step"
        return "simple"

    def retrieve(self, query, k=10):
        complexity = self._analyze_query(query)
        logger.info("AdaptiveRAG: complexity={}".format(complexity))
        
        if complexity == "simple":
            return self._simple_retrieve(query, k)
        elif complexity == "complex":
            return self._complex_retrieve(query, k)
        else:
            return self._multi_step_retrieve(query, k)

    def _simple_retrieve(self, query, k):
        query_embedding = self.embedding_model.embed_query(query)
        return self._deduplicate_results(self.vector_store.similarity_search(query_embedding, k), k)

    def _complex_retrieve(self, query, k):
        sub_queries = self._generate_sub_queries(query)
        all_results = {}
        
        for sq in sub_queries:
            sq_embedding = self.embedding_model.embed_query(sq)
            results = self.vector_store.similarity_search(sq_embedding, k // len(sub_queries) + 1)
            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 _multi_step_retrieve(self, query, k):
        all_results = []
        current_query = query
        
        for i in range(self.max_iterations):
            q_embedding = self.embedding_model.embed_query(current_query)
            step_results = self.vector_store.similarity_search(q_embedding, 5)
            all_results.extend(step_results)
            
            if len(all_results) >= k:
                break
            
            refinement_prompt = (
                "根据之前的查询，提出一个新的查询问题以获取更多信息。\n\n"
                "之前查询：{}\n\n"
                "新查询：".format(current_query)
            )
            current_query = self._call_llm(refinement_prompt)
        
        all_results.sort(key=lambda x: x[1], reverse=True)
        return self._deduplicate_results(all_results, k)

    def _generate_sub_queries(self, query):
        prompt = (
            "将以下问题分解为2-3个子问题，用逗号分隔。只返回子问题。\n\n"
            "原始问题：{}\n\n"
            "子问题：".format(query)
        )
        response = self._call_llm(prompt)
        return [q.strip() for q in response.split(",") if q.strip()]

    def generate(self, query, context):
        prompt = (
            "根据以下经过自适应检索的参考文档，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)