chatbot.py

import streamlit as st
import os
import openai

def get_completion(client, model_id, messages, args):
    completion_args = {
        "model": model_id,
        "messages": messages,
        "frequency_penalty": args.frequency_penalty,
        "max_tokens": args.max_tokens,
        "n": args.n,
        "presence_penalty": args.presence_penalty,
        "seed": args.seed,
        "stop": args.stop,
        "stream": args.stream,
        "temperature": args.temperature,
        "top_p": args.top_p,
    }

    completion_args = {
        k: v for k, v in completion_args.items() if v is not None
    }

    try:
        response = client.chat.completions.create(**completion_args)
        return response
    except Exception as e:
        print(f"Error during API call: {e}")
        return None

# App title 
st.set_page_config(page_title="Turing Test")

# OpenAI Client Setup
with st.sidebar:
    st.title('🦙💬 Welcome to Turing Test')
    
    # Hardcoded API key
    openai_api_key = "super-secret-token"
    # st.success('API key already provided!', icon='✅')
    
    os.environ['OPENAI_API_KEY'] = openai_api_key
    
    openai.api_key = openai_api_key
    openai.api_base = "https://turingtest--example-vllm-openai-compatible-serve.modal.run/v1"

    client = openai.OpenAI(api_key=openai_api_key, base_url=openai.api_base)

    # Add system prompt input
    st.subheader('System Prompt')
    system_prompt = st.text_area("Enter a system prompt:", 
                                 "you are rolplaying as an old grandma",
                                 help="This message sets the behavior of the AI.")
    st.subheader('Models and parameters')
    selected_model = st.sidebar.selectbox('Choose a model', ['meta-llama/Meta-Llama-3.1-8B-Instruct'], key='selected_model')
    temperature = st.sidebar.slider('temperature', min_value=0.01, max_value=5.0, value=0.8, step=0.1) 
    top_p = st.sidebar.slider('top_p', min_value=0.01, max_value=1.0, value=0.95, step=0.01)
    max_length = st.sidebar.slider('max_length', min_value=32, max_value=1024, value=32, step=8)
    

# Store chat history  
if "messages" not in st.session_state.keys():
    st.session_state.messages = [
        {"role": "system", "content": system_prompt},
        {"role": "assistant", "content": "Hello!"}
    ]
    
# Display chat messages (excluding system message)
for message in st.session_state.messages[1:]:
    with st.chat_message(message["role"]):
        st.write(message["content"])

def clear_chat_history():
    st.session_state.messages = [
        {"role": "system", "content": system_prompt},
        {"role": "assistant", "content": "Hello!"}
    ]
st.sidebar.button('Clear Chat History', on_click=clear_chat_history)

# Function for generating Llama2 response using OpenAI client API
def generate_llama2_response(prompt_input, model, temperature, top_p, max_length):
    
    class Args:
        def __init__(self):
            self.frequency_penalty = 0
            self.max_tokens = max_length
            self.n = 1 
            self.presence_penalty = 0
            self.seed = 42
            self.stop = None
            self.stream = False
            self.temperature = temperature
            self.top_p = top_p

    args = Args()
    
    # Update system message before each completion
    st.session_state.messages[0] = {"role": "system", "content": system_prompt}
    
    response = get_completion(client, model, st.session_state.messages, args)
    
    if response:
        return response.choices[0].message.content
    else:
        return "Sorry, there was an error generating a response."
        
# User-provided prompt 
if prompt := st.chat_input():
    st.session_state.messages.append({"role": "user", "content": prompt})
    with st.chat_message("user"):
        st.write(prompt)
        
# Generate response if last message is not from assistant
if st.session_state.messages[-1]["role"] != "assistant":
    with st.chat_message("assistant"):
        with st.spinner("Thinking..."):
            response = generate_llama2_response(prompt, selected_model, temperature, top_p, max_length)
            placeholder = st.empty()  
            full_response = ''
            for item in response:
                full_response += item  
                placeholder.markdown(full_response)
    message = {"role": "assistant", "content": full_response}
    st.session_state.messages.append(message)