import json
from pathlib import Path


class MemoryBuffer:
    def __init__(self, max_len=3, path="memory.json"):
        self.path = Path(path)
        self.max_len = max_len
        self.memory = []
        self.load()

    def add(self, user_input, bot_reply):
        self.memory.append(f"User: {user_input}")
        self.memory.append(f"Bot: {bot_reply}")
        if len(self.memory) > self.max_len * 2:
            self.memory = self.memory[-self.max_len * 2:]
        self.save()

    def get_context(self):
        return self.memory.copy()

    def save(self):
        with open(self.path, "w", encoding="utf-8") as f:
            json.dump(self.memory, f)

    def load(self):
        if self.path.exists():
            with open(self.path, "r", encoding="utf-8") as f:
                self.memory = json.load(f)