memory.py

import json
import os
from langchain_core.messages import HumanMessage, AIMessage

# save the chat inside the json file
def save_history(chat_history, chat_id):

    messages = []

    for message in chat_history:
        messages.append(
            {
                "type": message.type,
                "content": message.content
            }
        )

    history = {
        "chat_name": chat_history[0].content,
        "chat_id": chat_id,
        "messages": messages
    }

    with open(f"history/{chat_id}.json", "w") as f:
        json.dump(history, f, indent=4)

# get all chat names to display in sidebar  
def get_all_chats():

    chats = []

    for file in os.listdir("history"):

        if file.endswith(".json"):

            with open(f"history/{file}", "r") as f:
                chat = json.load(f)

            chats.append(chat)

    return chats


# load a particular chat on main screen when user clicks on that chat
def load_chat(chat_id):

    with open(f"history/{chat_id}.json", "r") as f:
        chat = json.load(f)

    chat_history = []

    for message in chat["messages"]:

        if message["type"] == "human":
            chat_history.append(
                HumanMessage(content=message["content"])
            )

        elif message["type"] == "ai":
            chat_history.append(
                AIMessage(content=message["content"])
            )

    return chat_history

def delete_chat(chat_id):

    file_path = f"history/{chat_id}.json"

    if os.path.exists(file_path):
        os.remove(file_path)

# """
# One small note: chat_history[0].content assumes the first message is always a HumanMessage, 
# which is true for your application. So this is a good solution for now.
# """