"""
설정 관리 모듈
────────────
환경 변수 기반 설정 관리
"""

import os
from dataclasses import dataclass
from typing import Optional


@dataclass
class Config:
    """RAG 시스템 설정"""
    
    # 벡터 검색 설정
    top_k: int
    threshold: float
    threshold_rewrite: float
    hybrid_search_enabled: bool
    sparse_top_k: int
    hybrid_merge_top_k: int
    
    # 재랭킹 설정
    rerank_candidates: int
    rerank_batch_size: int
    top_n_for_llm: int
    # 리랭커 1위 점수 미만 → 제안 문구·Full Context Rewriting (Qwen3-Reranker sigmoid 0~1)
    low_confidence_threshold: float
    # low 이상이면 medium, 이상이면 high (MongoDB answer_confidence)
    high_confidence_threshold: float
    
    # LLM 설정
    llm_max_tokens: int
    
    # Query Rewriting 설정
    query_rewrite_enabled: bool
    
    # 대화 이력 설정
    chat_history_enabled: bool
    chat_history_limit: int
    chat_history_hours: int
    chat_history_always_include: bool
    
    @classmethod
    def from_env(cls, chat_history_enabled: bool = False) -> "Config":
        """환경 변수에서 설정 로드"""
        return cls(
            # 벡터 검색
            top_k=int(os.getenv("FAISS_TOP_K", "30")),
            threshold=float(os.getenv("FAISS_THRESHOLD", "0.55")),
            threshold_rewrite=float(os.getenv("FAISS_THRESHOLD_REWRITE", "0.50")),
            hybrid_search_enabled=os.getenv("HYBRID_SEARCH_ENABLED", "false").lower() == "true",
            sparse_top_k=int(os.getenv("SPARSE_TOP_K", "30")),
            hybrid_merge_top_k=int(os.getenv("HYBRID_MERGE_TOP_K", "40")),
            
            # 재랭킹
            rerank_candidates=int(os.getenv("RERANK_CANDIDATES", "20")),
            rerank_batch_size=int(os.getenv("RERANK_BATCH_SIZE", "16")),
            top_n_for_llm=int(os.getenv("TOP_N_FOR_LLM", "5")),
            low_confidence_threshold=float(os.getenv("LOW_CONFIDENCE_THRESHOLD", "0.65")),
            high_confidence_threshold=float(os.getenv("HIGH_CONFIDENCE_THRESHOLD", "0.75")),
            
            # LLM
            llm_max_tokens=int(os.getenv("LLM_MAX_TOKENS", "2048")),
            
            # Query Rewriting
            query_rewrite_enabled=os.getenv("QUERY_REWRITE_ENABLED", "true").lower() == "true",
            
            # 대화 이력
            chat_history_enabled=chat_history_enabled,
            chat_history_limit=int(os.getenv("CHAT_HISTORY_LIMIT", "10")),
            chat_history_hours=int(os.getenv("CHAT_HISTORY_HOURS", "24")),
            chat_history_always_include=os.getenv("CHAT_HISTORY_ALWAYS_INCLUDE", "true").lower() == "true"
        )
    
    def print_summary(self):
        """설정 요약 출력"""
        print(f"[Config] Query Rewriting: {'활성화' if self.query_rewrite_enabled else '비활성화'}")
        print(f"[Config] FAISS Threshold: 1차={self.threshold}, 2차(Rewrite)={self.threshold_rewrite}")
        print(
            f"[Config] Hybrid Search: {'활성화' if self.hybrid_search_enabled else '비활성화'} "
            f"(sparse_top_k={self.sparse_top_k}, merge_top_k={self.hybrid_merge_top_k})"
        )
        print(
            f"[Config] Reranker 신뢰도: low<{self.low_confidence_threshold}, "
            f"high>={self.high_confidence_threshold}"
        )
        print(f"[Config] 대화 이력: {'활성화' if self.chat_history_enabled else '비활성화'}")
        if self.chat_history_enabled:
            print(f"[Config] - 최근 {self.chat_history_limit}개 / {self.chat_history_hours}시간")
            print(f"[Config] - 정상 질문 포함: {'예' if self.chat_history_always_include else '아니오'}")