app.py

# --- Importing Libraries ---
import streamlit as st
import config  # used only for default values
from openai import OpenAI
from typing import Dict, Any, List


def build_complete_system_prompt(selected_language: str, prompt_body: str) -> str:
    """
    Build the complete system prompt by combining the language instruction with the prompt body.

    Args:
        selected_language (str): The language chosen from the dropdown.
        prompt_body (str): The editable system prompt body.

    Returns:
        str: The complete system prompt with language instruction.
    """
    language_instruction = f"All your responses should be in {selected_language}.\n"
    return language_instruction + prompt_body


def reset_chat_history(initial_context: Dict[str, str]) -> None:
    """
    Reset the chat history to the initial context and rerun the app.

    Args:
        initial_context (Dict[str, str]): The initial chat context.
    """
    st.session_state["display_messages"] = [initial_context]
    st.rerun()


def stream_assistant_response(client: OpenAI, model: str, messages: List[Dict[str, str]],
                              temperature: float, max_tokens: int,
                              frequency_penalty: float, presence_penalty: float) -> str:
    """
    Stream the assistant's response from the OpenAI API and return the full response.

    Args:
        client (OpenAI): The initialized OpenAI client.
        model (str): The model to use.
        messages (List[Dict[str, str]]): The list of chat messages.
        temperature (float): The temperature setting.
        max_tokens (int): The maximum number of tokens.
        frequency_penalty (float): The frequency penalty.
        presence_penalty (float): The presence penalty.

    Returns:
        str: The complete assistant response.
    """
    full_response = ""
    message_placeholder = st.empty()
    try:
        stream = client.chat.completions.create(
            model=model,
            messages=messages,
            stream=True,
            temperature=temperature,
            max_tokens=max_tokens,
            frequency_penalty=frequency_penalty,
            presence_penalty=presence_penalty,
        )
        # Iterate through the stream to collect the response.
        for chunk in stream:
            if chunk.choices[0].delta.content is not None:
                full_response += chunk.choices[0].delta.content
                message_placeholder.markdown(full_response + "▌")
        message_placeholder.markdown(full_response)
    except Exception as e:
        st.exception(e)
        st.error(f"An error occurred: {str(e)}")
    return full_response


def main() -> None:
    """Main function to run the Streamlit Chatbot Prompt and Parameter Tester application."""
    # --- App Layout and Configuration ---
    st.set_page_config(
        layout="wide",
        page_title="OpenAI Chatbot Tester",
        page_icon=":lightbulb:",
        initial_sidebar_state="expanded"
    )
    st.title("OpenAI Chatbot Tester")

    # --- Sidebar: Configuration Inputs ---
    with st.sidebar:
        st.header("Configuration")

        # API Key Input Field
        api_key = st.text_input(
            "OpenAI API Key",
            type="password",
            key="api_key",
            help="This is the API key for your OpenAI account. You can find it [here](https://platform.openai.com/api-keys)."
        )
        if api_key:
            st.session_state["OPENAI_API_KEY"] = api_key
        else:
            st.warning("Please provide your OpenAI API key to enable chat functionality.")

        # Dropdown for model selection.
        model_options = ["gpt-4.1", "gpt-4o", "gpt-4o-mini"]
        default_model = config.ai_model if config.ai_model in model_options else model_options[0]
        selected_model = st.selectbox(
            "Model",
            options=model_options,
            index=model_options.index(default_model),
            help="This controls the model used for the chatbot. You can choose from the following models: gpt-4o, gpt-4o-mini"
        )
        st.session_state["openai_model"] = selected_model

        # Slider for temperature.
        temperature = st.slider(
            "Temperature",
            0.0, 1.0,
            value=config.temperature,
            step=0.05,
            help="This controls the randomness/creativity of the responses. A higher temperature results in more creative responses."
        )
        st.session_state["temperature"] = temperature

        # Number input for maximum tokens.
        max_tokens = st.number_input(
            "Max Tokens",
            min_value=1,
            max_value=2048,
            value=config.max_tokens,
            step=1,
            help="This controls the maximum number of tokens the AI can generate. 1000 tokens equals about 750 words."
        )
        st.session_state["max_tokens"] = max_tokens

        # Slider for frequency penalty.
        frequency_penalty = st.slider(
            "Frequency Penalty",
            0.0, 1.0,
            value=config.frequency_penalty,
            step=0.05,
            help="This controls the frequency penalty for the responses. Higher values produce more diverse responses."
        )
        st.session_state["frequency_penalty"] = frequency_penalty

        # Slider for presence penalty.
        presence_penalty = st.slider(
            "Presence Penalty",
            0.0, 1.0,
            value=config.presence_penalty,
            step=0.05,
            help="This controls the presence penalty for the responses. Higher values reduce repetition."
        )
        st.session_state["presence_penalty"] = presence_penalty

        # Language selection dropdown.
        language_options = [
            "English", "Albanian", "Amharic", "Arabic", "Armenian", "Bengali", "Bosnian", "Bulgarian", "Burmese",
            "Catalan", "Chinese", "Croatian", "Czech", "Danish", "Dutch", "Estonian", "Finnish", "French",
            "Georgian", "German", "Greek", "Gujarati", "Hindi", "Hungarian", "Icelandic", "Indonesian",
            "Italian", "Japanese", "Kannada", "Kazakh", "Korean", "Latvian", "Lithuanian", "Macedonian",
            "Malay", "Malayalam", "Marathi", "Mongolian", "Norwegian", "Persian", "Polish", "Portuguese",
            "Punjabi", "Romanian", "Russian", "Serbian", "Slovak", "Slovenian", "Somali", "Spanish",
            "Swahili", "Swedish", "Tagalog", "Tamil", "Telugu", "Thai", "Turkish", "Ukrainian", "Urdu",
            "Vietnamese"
        ]
        default_language = "English"
        if default_language not in language_options:
            language_options.insert(0, default_language)
        selected_language = st.selectbox(
            "Preferred Language",
            options=language_options,
            index=language_options.index(default_language),
            help="Select your preferred language for the chatbot's responses."
        )

        st.markdown("Click the 'Update Configuration' button each time you change an option.")

        st.markdown("---")

    # --- System Instructions ---
    # Retrieve the editable prompt body from session state or default config.
    default_body = st.session_state.get("system_prompt_body", config.prompt)
    system_prompt_body = st.text_area(
        "System Instructions",
        value=default_body,
        key="system_prompt_body",
        help="These instructions determine the chatbot's behavior. Click 'Update Configuration' to apply changes.",
        height=400
    )
    complete_system_prompt = build_complete_system_prompt(selected_language, system_prompt_body)
    st.session_state["system_prompt"] = complete_system_prompt

    # --- Chat State Initialization ---
    initial_context: Dict[str, str] = {
        "role": "system",
        "content": complete_system_prompt
    }

    # --- Update System Instructions Button ---
    if st.button("Update Configuration"):
        reset_chat_history(initial_context)

    # Ensure the API key is provided.
    if not st.session_state.get("OPENAI_API_KEY"):
        st.error("No API key provided. Please enter your OpenAI API key above.")
        st.stop()

    # Initialize the OpenAI client.
    client = OpenAI(api_key=st.session_state["OPENAI_API_KEY"])

    # Initialize session state variables if not already set.
    if "openai_model" not in st.session_state:
        st.session_state["openai_model"] = config.ai_model

    if "display_messages" not in st.session_state:
        st.session_state["display_messages"] = [initial_context]

    # --- Chat Input ---
    prompt = st.chat_input("Type your message here...")
    if prompt:
        st.session_state["display_messages"].append({"role": "user", "content": prompt})

    # --- Chat Display and Response Generation ---
    with st.container():
        # Display chat history.
        for message in st.session_state["display_messages"][1:]:
            if message["role"] == "user":
                with st.chat_message("user"):
                    st.markdown(message["content"])
            else:
                with st.chat_message("assistant"):
                    st.markdown(message["content"])

        # Generate the assistant's response if there is new input.
        if prompt:
            with st.chat_message("assistant"):
                full_response = stream_assistant_response(
                    client=client,
                    model=selected_model,
                    messages=[{"role": m["role"], "content": m["content"]}
                              for m in st.session_state["display_messages"]],
                    temperature=temperature,
                    max_tokens=max_tokens,
                    frequency_penalty=frequency_penalty,
                    presence_penalty=presence_penalty
                )
                st.session_state["display_messages"].append(
                    {"role": "assistant", "content": full_response}
                )

    # --- Footer ---
    with st.sidebar:
        st.markdown("Application created by [Keefe Reuther](https://reutherlab.netlify.app/), Assistant Teaching Professor in the UC San Diego School of Biological Sciences. "
                    "Code for this app is available [here](https://huggingface.co/spaces/keefereuther/ST_basebot) and is distributed under the [GNU GPL-3 License](https://www.gnu.org/licenses/gpl-3.0.en.html).")

    # --- Debug Block: Display Session State ---
    with st.sidebar.expander("Debug: Session State"):
        session_state_copy = {k: v for k, v in st.session_state.items() if k not in ["display_messages", "api_key", "OPENAI_API_KEY"]}
        st.json(session_state_copy)


if __name__ == "__main__":
    main()