import json
from pathlib import Path

class KnowledgeBase:
    def __init__(self, storage_path="kb.json"):
        self.storage_path = Path(storage_path)
        if not self.storage_path.exists():
            self._save({})
        self.data = self._load()

    def _load(self):
        with self.storage_path.open("r") as f:
            return json.load(f)

    def _save(self, data):
        with self.storage_path.open("w") as f:
            json.dump(data, f, indent=2)

    def get(self, topic):
        return self.data.get(topic.lower(), "❓ No entry found.")

    def set(self, topic, content):
        self.data[topic.lower()] = content
        self._save(self.data)
        return f"✅ Knowledge added for topic: '{topic}'"

    def search(self, query):
        return {k: v for k, v in self.data.items() if query.lower() in k or query.lower() in v}

    def list_topics(self):
        return list(self.data.keys())