import streamlit as st
import os

import openai
from openai import OpenAI

# App title
st.set_page_config(page_title="💬 Open AI Chatbot")
openai_api = os.getenv("OPENAI_API_KEY")

# Replicate Credentials
with st.sidebar:
    st.title("💬 Open AI Chatbot")
    st.write("This chatbot is created using the GPT model from Open AI.")
    if openai_api:
        pass
    elif "OPENAI_API_KEY" in st.secrets:
        st.success("API key already provided!", icon="✅")
        openai_api = st.secrets["OPENAI_API_KEY"]
    else:
        openai_api = st.text_input("Enter OpenAI API token:", type="password")
        if not (openai_api.startswith("sk-") and len(openai_api)==51):
            st.warning("Please enter your credentials!", icon="⚠️")
        else:
            st.success("Proceed to entering your prompt message!", icon="👉")

    ### for streamlit purpose
    os.environ["OPENAI_API_KEY"] = openai_api

    st.subheader("Models and parameters")
    selected_model = st.sidebar.selectbox("Choose an OpenAI model", 
                                          ["gpt-3.5-turbo-1106", "gpt-4-1106-preview"], 
                                           key="selected_model")
    temperature = st.sidebar.slider("temperature", min_value=0.01, max_value=2.0, 
                                    value=0.1, step=0.01)
    st.markdown("📖 Reach out to SakiMilo to learn how to create this app!")

# Store LLM generated responses
if "messages" not in st.session_state.keys():
    st.session_state.messages = [{"role": "assistant", 
                                  "content": "How may I assist you today?"}]

# Display or clear chat messages
for message in st.session_state.messages:
    with st.chat_message(message["role"]):
        st.write(message["content"])

def clear_chat_history():
    st.session_state.messages = [{"role": "assistant", 
                                  "content": "How may I assist you today?"}]
st.sidebar.button("Clear Chat History", on_click=clear_chat_history)

def generate_llm_response(client, prompt_input):
    system_content = ("You are a helpful assistant. "
                      "You do not respond as 'User' or pretend to be 'User'. "
                      "You only respond once as 'Assistant'."
    )

    completion = client.chat.completions.create(
                    model=selected_model,
                    messages=[
                            {"role": "system", "content": system_content},
                    ] + st.session_state.messages,
                    temperature=temperature,
                    stream=True
    )
    return completion

# User-provided prompt
if prompt := st.chat_input(disabled=not openai_api):
    client = OpenAI()
    st.session_state.messages.append({"role": "user", "content": prompt})
    with st.chat_message("user"):
        st.write(prompt)

# Generate a new 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_llm_response(client, prompt)
            placeholder = st.empty()
            full_response = ""
            for chunk in response:
                if chunk.choices[0].delta.content is not None:
                    full_response += chunk.choices[0].delta.content
                    placeholder.markdown(full_response)
            placeholder.markdown(full_response)
    message = {"role": "assistant", "content": full_response}
    st.session_state.messages.append(message)