"""
Nova Persistent Chat Memory Engine
Manages long-term conversational history, saves memory to disk, and restores context across sessions.
"""

import os
import json
from typing import List, Dict


class NovaChatMemory:
    def __init__(self, storage_path: str = None):
        if storage_path is None:
            root_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), "..", ".."))
            storage_path = os.path.join(root_dir, "checkpoints", "chat_memory.json")

        self.storage_path = storage_path
        self.history: List[Dict[str, str]] = []
        self.load_memory()

    def add_user_message(self, content: str):
        self.history.append({"role": "user", "content": content})
        self.save_memory()

    def add_assistant_message(self, content: str):
        self.history.append({"role": "assistant", "content": content})
        self.save_memory()

    def get_messages(self) -> List[Dict[str, str]]:
        return self.history

    def clear(self):
        self.history = []
        self.save_memory()

    def save_memory(self):
        try:
            os.makedirs(os.path.dirname(self.storage_path), exist_ok=True)
            with open(self.storage_path, "w", encoding="utf-8") as f:
                json.dump(self.history, f, indent=2)
        except Exception as e:
            print(f"Error saving chat memory: {e}")

    def load_memory(self):
        if os.path.exists(self.storage_path):
            try:
                with open(self.storage_path, "r", encoding="utf-8") as f:
                    self.history = json.load(f)
            except Exception as e:
                print(f"Error loading chat memory: {e}")
                self.history = []
        else:
            self.history = []