app.py

import streamlit as st
from streamlit_chat import message
from openai import OpenAI
import time
import datetime
import os

# Securely get credentials
generated_user = os.getenv("User")
generated_password = os.getenv("Password")
openai_key = os.getenv("openai_key")

# Streamlit page config
st.set_page_config(page_title="Carfind.co.za AI Assistant", layout="wide")
st.title("🚗 Carfind.co.za AI Assistant")
st.caption("Chat with Carfind.co.za and find your next car fast")

# Theme toggle
if "theme" not in st.session_state:
    st.session_state.theme = "dark"

toggle = st.toggle("Switch to Light Mode")
if toggle:
    st.session_state.theme = "light"
else:
    st.session_state.theme = "dark"

if st.session_state.theme == "light":
    st.markdown(
        """
        <style>
        body { background-color: #f0f0f0; color: #000; }
        </style>
        """,
        unsafe_allow_html=True
    )
else:
    st.markdown(
        """
        <style>
        body { background-color: #0e0e0e; color: #fff; }
        </style>
        """,
        unsafe_allow_html=True
    )

# Initialize authentication and state
if "authenticated" not in st.session_state:
    st.session_state.authenticated = False
if "messages" not in st.session_state:
    st.session_state["messages"] = []
if "last_user_input" not in st.session_state:
    st.session_state.last_user_input = ""
if "last_assistant_response" not in st.session_state:
    st.session_state.last_assistant_response = ""

# Login screen
if not st.session_state.authenticated:
    st.subheader("🔐 Login")
    username = st.text_input("Username")
    password = st.text_input("Password", type="password")

    if username and password:
        if username == generated_user and password == generated_password:
            st.session_state.authenticated = True
            st.success("Login successful! Redirecting...")
            time.sleep(1)
            st.rerun()
        else:
            st.error("Incorrect username or password. Please try again.")

# Main chat UI
else:
    st.divider()

    # Display chat history
    for i, msg in enumerate(st.session_state["messages"]):
        if msg["role"] == "assistant":
            st.markdown(f'<img src="https://www.carfind.co.za/images/Carfind-Icon.svg" width="30" style="vertical-align: middle;"> <strong>Carfind Assistant:</strong> {msg["content"]}', unsafe_allow_html=True)
        else:
            message(
                msg["content"],
                is_user=True,
                key=str(i),
                avatar_style="adventurer",
                seed="user-seed"
            )

    col_input, col_clear = st.columns([10, 1])

    with col_input:
        user_input = st.text_input("Type your message here:", key="input")

    with col_clear:
        if st.button("🗑️", help="Clear chat"):
            st.session_state.messages = []
            st.session_state.last_user_input = ""
            st.session_state.last_assistant_response = ""
            st.rerun()

    # Only trigger on new distinct input
    if user_input and user_input != st.session_state.last_user_input and openai_key:
        st.session_state.last_user_input = user_input
        st.session_state.messages.append({"role": "user", "content": user_input})

        with st.spinner("Thinking and typing... 💬"):
            client = OpenAI(api_key=openai_key)
            ASSISTANT_ID = "asst_5gQR21fOsmHil11FGBzEArA7"

            def save_transcript(messages):
                with open("chat_logs.txt", "a") as log:
                    log.write(f"\n--- New Chat ({datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')}) ---\n")
                    for msg in messages:
                        log.write(f"{msg['role'].capitalize()}: {msg['content']}\n")
                    log.write("--- End Chat ---\n")

            try:
                thread = client.beta.threads.create()
                thread_id = thread.id

                client.beta.threads.messages.create(
                    thread_id=thread_id,
                    role="user",
                    content=user_input
                )

                run = client.beta.threads.runs.create(
                    thread_id=thread_id,
                    assistant_id=ASSISTANT_ID
                )

                while True:
                    run_status = client.beta.threads.runs.retrieve(
                        thread_id=thread_id,
                        run_id=run.id
                    )
                    if run_status.status == "completed":
                        break
                    time.sleep(1)

                messages_response = client.beta.threads.messages.list(thread_id=thread_id)
                assistant_reply = messages_response.data[0].content[0].text.value.strip()

                if (assistant_reply.lower() != user_input.lower() and
                    assistant_reply != st.session_state.last_assistant_response):
                    st.session_state.messages.append({"role": "assistant", "content": assistant_reply})
                    st.session_state.last_assistant_response = assistant_reply
                    save_transcript(st.session_state.messages)

                st.rerun()

            except Exception as e:
                st.error(f"An error occurred: {str(e)}")

    elif not openai_key:
        st.error("OpenAI key not found. Please ensure it is set as a Hugging Face secret.")