src/st-chat-app.py

import requests
import json
import streamlit as st
import os
from dotenv import load_dotenv
load_dotenv()

# Page config should be the first Streamlit command
st.set_page_config(
    page_title="Chat with Einstein LLMs!",
    page_icon=":brain:",
    layout="wide",
)

# Initialize session state for authentication
if "authenticated" not in st.session_state:
    st.session_state.authenticated = False

def check_password():
    """Returns `True` if the user had the correct password."""
    password_input = os.getenv("PASSWORD")
    def password_entered():
        """Checks whether a password entered by the user is correct."""
        if st.session_state["password"] == password_input:
            st.session_state.authenticated = True
            del st.session_state["password"]  # Remove password from session state for security
        else:
            st.session_state.authenticated = False
            st.error("😕 Password incorrect")

    # Show input for password
    st.text_input(
        "Please enter the password to access the Einstein Assistant",
        type="password",
        on_change=password_entered,
        key="password"
    )
    
    # if not st.session_state.authenticated:
    #     st.error("😕 Password incorrect")
    #     return False
    # return True

# Show chat interface only if authenticated
if st.session_state.authenticated:
    client_id = os.getenv("CLIENT_ID")
    client_secret = os.getenv("CLIENT_SECRET")
    base_url = os.getenv("BASE_URL")

    def get_access_token():
        url = base_url+"/services/oauth2/token"
        payload = {
        "grant_type": "client_credentials",
        "client_id": client_id,
        "client_secret": client_secret
        }
        response = requests.post(url, data=payload)
        # Add error handling for response
        if response.status_code != 200:
            st.error(f"Error fetching access token: {response.status_code} - {response.text}")
            return None
        data = response.json()
        access_token = data.get('access_token', 'Token not found')
        return access_token

    # Add model selection dictionary
    MODEL_OPTIONS = {
        "GPT4-Omni": "sfdc_ai__DefaultOpenAIGPT4Omni",
        "Gemini": "sfdc_ai__DefaultVertexAIGemini20Flash001",
        "Claude": "sfdc_ai__DefaultBedrockAnthropicClaude37Sonnet"
    }

    # Add sidebar with model selection
    with st.sidebar:
        st.title("Model Settings")
        selected_model_name = st.selectbox(
            "Choose AI Model",
            options=list(MODEL_OPTIONS.keys()),
            index=0
        )
        model = MODEL_OPTIONS[selected_model_name]

    # Update the page title to reflect selected model
    st.subheader(f"🤖 Chat with {selected_model_name}")

    # Modify get_gpt_response function to use selected model
    def get_gpt_response(prompt):
        url = f"https://api.salesforce.com/einstein/platform/v1/models/{model}/chat-generations"
        access_token = get_access_token()
        headers = {
            "Authorization": f"Bearer {access_token}",
            "Content-Type": "application/json;charset=utf-8",
            'x-sfdc-app-context': 'EinsteinGPT',
            'x-client-feature-id': 'ai-platform-models-connected-app'
        }
        chat_payload = {
            "messages": prompt
        }

        try:
            response = requests.post(url, headers=headers, data=json.dumps(chat_payload))
            response.raise_for_status()  # Raise exception for bad status codes
            data = response.json()
            return data["generationDetails"]["generations"][0]["content"]
        except requests.exceptions.RequestException as e:
            st.error(f"Error calling the API: {str(e)}")
            return "I apologize, but I encountered an error. Please try again."
        except (KeyError, IndexError) as e:
            st.error(f"Error parsing response: {str(e)}")
            return "I apologize, but I received an invalid response. Please try again."

    # Display the chatbot's title on the page
    if "messages" not in st.session_state:
        st.session_state["messages"] = [{"role": "assistant", "content": "How can I help you?"}]

    for msg in st.session_state.messages:
        st.chat_message(msg["role"], avatar="🤖").write(msg["content"])
        if "image" in msg:
            st.image(msg["image"])

    prompt = st.chat_input(
        "Say something and/or attach an image",
        accept_file=True,
        file_type=["jpg", "jpeg", "png"],
    )

    if prompt:
        # Handle text input
        if prompt.text:
            st.session_state.messages.append({"role": "user", "content": prompt.text})
            st.chat_message("user").write(prompt.text)
            
        # Handle image upload
        if prompt.get("files"):
            uploaded_file = prompt["files"][0]
            st.session_state.messages.append({
                "role": "user", 
                "content": "Uploaded an image",
                "image": uploaded_file
            })
            st.chat_message("user").write("Uploaded an image")
            st.image(uploaded_file)
        
        # Get AI response if there's any input
        if prompt.text or prompt.get("files"):
            msg = get_gpt_response(st.session_state.messages)
            st.session_state.messages.append({"role": "assistant", "content": msg})
            st.chat_message("assistant", avatar="🤖").write(msg)
else:
    # Show login page
    st.title("Welcome to Einstein Assistant")
    #st.markdown("Please log in to continue")
    check_password()