"""
Knowledge Base Service
ローカルファイルからKnowledge Baseを読み込む
"""

import os
import logging
from pathlib import Path
from typing import Optional

logger = logging.getLogger(__name__)

# 教科コードとファイル名のマッピング
SUBJECT_TO_FILE = {
    "jp": "japanese.md",
    "math": "math.txt",
    "sci": "science.md",
    "soc": "social.md"
}

# 教科コードと日本語名のマッピング
SUBJECT_TO_NAME = {
    "jp": "国語",
    "math": "算数",
    "sci": "理科",
    "soc": "社会"
}


class KnowledgeService:
    """Knowledge Base読み込みサービス"""

    def __init__(self, knowledge_dir: str = "knowledge"):
        self.knowledge_dir = Path(knowledge_dir)
        self._cache = {}  # ファイル内容キャッシュ
        self._load_all()

    def _load_all(self):
        """全教科のKBを読み込んでキャッシュ"""
        for subject, filename in SUBJECT_TO_FILE.items():
            filepath = self.knowledge_dir / filename
            if filepath.exists():
                try:
                    with open(filepath, "r", encoding="utf-8") as f:
                        self._cache[subject] = f.read()
                    logger.info(f"Loaded KB for {subject}: {len(self._cache[subject])} chars")
                except Exception as e:
                    logger.error(f"Failed to load KB for {subject}: {e}")
                    self._cache[subject] = ""
            else:
                logger.warning(f"KB file not found: {filepath}")
                self._cache[subject] = ""

    def is_available(self) -> bool:
        """サービス利用可能かチェック"""
        return any(len(content) > 0 for content in self._cache.values())

    def get_knowledge(self, subject: str) -> str:
        """
        指定教科のKnowledge Base内容を取得

        Args:
            subject: 教科コード (jp, math, sci, soc)

        Returns:
            Knowledge Baseの内容
        """
        return self._cache.get(subject, "")

    def get_subject_name(self, subject: str) -> str:
        """教科コードから日本語名を取得"""
        return SUBJECT_TO_NAME.get(subject, subject)

    def get_all_subjects(self) -> list:
        """利用可能な教科リストを取得"""
        return [s for s, content in self._cache.items() if len(content) > 0]

    def get_kb_stats(self) -> dict:
        """KB統計情報を取得"""
        return {
            subject: {
                "chars": len(content),
                "lines": content.count("\n") + 1 if content else 0
            }
            for subject, content in self._cache.items()
        }