app.py

from transformers import pipeline
import streamlit as st

# Set up Streamlit app title and page width
st.set_page_config(page_title='Simple Chatbot with Streamlit', layout='wide')

# Load conversational pipeline
chatbot = pipeline("text2text-generation", model="facebook/blenderbot-400M-distill")

# Initialize chat history in session state
if 'chat_history' not in st.session_state:
    st.session_state['chat_history'] = []

# Define Streamlit app layout
st.markdown("""
<style>
    body {
        background-color: #f0f2f6;
    }
    .stApp {
        max-width: 800px;
        margin: auto;
        padding-top: 50px;
    }
    .stTextInput {
        margin-bottom: 20px;
    }
    .stButton button {
        background-color: #4CAF50; /* Green */
        border: none;
        color: white;
        padding: 15px 32px;
        text-align: center;
        text-decoration: none;
        display: inline-block;
        font-size: 16px;
        margin: 4px 2px;
        cursor: pointer;
        border-radius: 5px;
    }
    .stButton button:hover {
            background-color: #7EC0EE; /* Darker sky blue on hover */
        }
    .chat-container {
        padding:6px;
        border-radius: 5px;
        overflow: hidden;
        box-shadow: 0 4px 8px rgba(255, 255, 255, 0.3);
        # border: 1px solid #d3d3d3;
        overflow: hidden;
    }
    .user-message {
        background-color: #4CAF50;
        color: white;
        padding: 10px 20px;
        margin: 5px;
        border-radius: 5px;
        clear: both;
        float: left;
    }
    .bot-message {
        background-color: #f1f1f1;
        color: black;
        padding: 10px 20px;stButton
        margin: 5px;
        border-radius: 5px;
        clear: both;
        float: right;
    }
 
</style>
""", unsafe_allow_html=True)

# Define Streamlit app layout
st.markdown("<h1 style='color: orange;'>💬 Chatbot</h1>", unsafe_allow_html=True)
st.caption("🚀 Chat bot created By :- [Dinesh Abeysinghe (AI-ML Engineer)](https://www.linkedin.com/in/dinesh-abeysinghe-bb773293)")

# Create text area for user input
user_input = st.text_input("", placeholder="Your message")


# Define Streamlit app behavior
if st.button('Send'):
    if not user_input.strip():  # Check if input is empty or whitespace
        st.error('Please enter a chat')
    else:
        chat_history = st.session_state['chat_history']
        chat_history.append({"role": "user", "message": user_input})

        with st.spinner(text='Thinking ...'):
            conversation_bot_result = chatbot(user_input)
        
        bot_response = conversation_bot_result[0]["generated_text"]
        chat_history.append({"role": "bot", "message": bot_response})

        # Update chat history in session state
        st.session_state['chat_history'] = chat_history
        
 
# Create text area for chat history
chat_area = st.empty()

# Display the chat history with alternating user and bot messages
chat_text = ""
user_messages = [chat for chat in st.session_state['chat_history'] if chat['role'] == 'user']
bot_messages = [chat for chat in st.session_state['chat_history'] if chat['role'] == 'bot']

for user_chat, bot_chat in zip(reversed(user_messages), reversed(bot_messages)):
    chat_text += f"<div class='user-message'>{user_chat['message']}</div>\n"
    chat_text += f"<div class='bot-message'>{bot_chat['message']}</div>\n"

# Add any remaining user messages if there are more user messages than bot messages
for user_chat in reversed(user_messages[len(bot_messages):]):
    chat_text += f"<div class='user-message'>{user_chat['message']}</div>\n"

chat_area.markdown(f"<div class='chat-container'>{chat_text}</div>", unsafe_allow_html=True)