app.py

# mesop app.py --port 8080

import os
import json
import mesop as me
import mesop.labs as mel
from dotenv import load_dotenv
import google.generativeai as genai
from google.generativeai.types.generation_types import GenerateContentResponse
from typing import Generator


DEFAULT_CONFIG_PATH = "./config.json"
DEFAULT_MODEL_NAME = "learnlm-1.5-pro-experimental"

# Load environment variables from .env file
load_dotenv()

rolemap = {"user": "user", "assistant": "model"}


genai.configure(api_key=os.getenv("GOOGLE_API_KEY"))

# Create the model
generation_config = {
    "temperature": 1,
    "top_p": 0.95,
    "top_k": 64,
    "max_output_tokens": 8192,
    "response_mime_type": "text/plain",
}


# Load config once
_config: dict|None = None
def _load_config():
    global _config
    global generation_config
    config_path = os.environ.get("CHAT_CONFIG_PATH", DEFAULT_CONFIG_PATH)
    try:
        with open(config_path, 'r') as f:
            _config = json.load(f)
        # print(f"Successfully loaded config from: {config_path}")
        if _config:
            generation_config.update(_config.get('generation_config', generation_config))
            # print(f"Updated generation_config: {generation_config}")
    except FileNotFoundError:
        print(f"Warning: Could not read config file at: {config_path}")
    except json.JSONDecodeError as e:
        print(f"Error parsing config file: {e}")

_load_config()


model = genai.GenerativeModel(
  model_name=os.environ.get("MODEL_NAME", DEFAULT_MODEL_NAME),
  generation_config=generation_config,
  system_instruction=_config['prompt']['es']
)

# TODO This function is not being called, why???
def on_load(e: me.LoadEvent):
    print("***On load event***")



@me.stateclass
class FirstState:
    first:str|None = None


@me.page(
    security_policy=me.SecurityPolicy(
        allowed_iframe_parents=["https://google.github.io", "https://huggingface.co"]
    ),
    path="/",
    title="Mesop Demo Chat",
)
def page():
    if _config:
        try:
            welcome_message = _config["welcome_message"]
            # me.text(welcome_message)
        except KeyError:
            print("Error: 'welcome_message' not found in config file.")
    else:
        print("Config not loaded, using default values.")
        me.text("Welcome to the Chat (Default)")
    
    # me.box(
    #     me.text("This is a chat interface where you can interact with the DSA Tutor. Please enter your questions below:"),
    #     style=me.Style(padding=me.Padding(bottom=12))
    # )
    state = me.state(FirstState)
    if 'start_prompt' in me.query_params:
        start_prompt:str = me.query_params['start_prompt']
        #print('start_prompt', start_prompt)
        del me.query_params['start_prompt']
        state.first = start_prompt

    mel.chat(transform, title="DSA Tutor", bot_user="Tutor", )


def transform(input: str, history: list[mel.ChatMessage]) -> Generator[str, None, None]:
    messages = []
    state = me.state(FirstState)
    if state.first:
        # print('first', state.first)
        messages.append({"role": "user", "parts": [state.first]})
    messages.extend([
        {"role": rolemap[message.role], "parts": [message.content]}
        for message in history
    ])
    # print('messages', messages)
    chat_session = model.start_chat(history=messages)
    response:GenerateContentResponse = chat_session.send_message(input, stream=True)
    text = ""
    for chunk in response:
        text += chunk.text
        yield chunk.text