app_streamlit.py

import streamlit as st
import os
import sys
import asyncio

# Add backend to path for imports
backend_path = os.path.join(os.path.dirname(os.path.abspath(__file__)), 'backend')
sys.path.insert(0, backend_path)

# Use lightweight character manager for HuggingFace Spaces
from backend.models.lightweight_character_manager import CharacterManager

# Page config
st.set_page_config(
    page_title="🎭 Roleplay Chat Box",
    page_icon="🎭",
    layout="wide"
)

# Initialize session state
if 'character_manager' not in st.session_state:
    st.session_state.character_manager = None
if 'messages' not in st.session_state:
    st.session_state.messages = []
if 'current_character' not in st.session_state:
    st.session_state.current_character = 'moses'

def initialize_models():
    """Initialize the character manager"""
    if st.session_state.character_manager is None:
        with st.spinner("🔄 Loading character models..."):
            try:
                st.session_state.character_manager = CharacterManager()
                loop = asyncio.new_event_loop()
                asyncio.set_event_loop(loop)
                loop.run_until_complete(st.session_state.character_manager.initialize())
                loop.close()
                st.success("✅ Models loaded successfully!")
                return True
            except Exception as e:
                st.error(f"❌ Error loading models: {str(e)}")
                import traceback
                st.error(traceback.format_exc())
                return False
    return True

# Sidebar for character selection
with st.sidebar:
    st.title("🎭 Characters")
    
    character = st.radio(
        "Choose Character",
        options=["moses", "samsung_employee", "jinx"],
        format_func=lambda x: {
            "moses": "📜 Moses - Biblical Prophet",
            "samsung_employee": "💼 Samsung Employee - Tech Expert",
            "jinx": "💥 Jinx - Chaotic Genius"
        }[x],
        key="character_selector"
    )
    
    # Update character if changed
    if character != st.session_state.current_character:
        st.session_state.current_character = character
        st.session_state.messages = []
    
    st.divider()
    
    if st.button("🗑️ Clear Chat"):
        st.session_state.messages = []
        st.rerun()
    
    st.divider()
    st.markdown("### About")
    st.markdown("""
    This app uses LoRA (Low-Rank Adaptation) to create unique character personalities.
    
    - **Base Model**: Qwen3-0.6B
    - **Adapters**: Character-specific LoRA weights
    - **Memory Efficient**: Shares one base model
    """)

# Main chat interface
st.title("🎭 Roleplay Chat Box")
st.markdown(f"Currently chatting with: **{st.session_state.current_character}**")

# Initialize models on first run
if not initialize_models():
    st.stop()

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

# Chat input
if prompt := st.chat_input("Type your message here..."):
    # Add user message to chat
    st.session_state.messages.append({"role": "user", "content": prompt})
    with st.chat_message("user"):
        st.markdown(prompt)
    
    # Generate response
    with st.chat_message("assistant"):
        with st.spinner("Thinking..."):
            try:
                # Convert history for context
                conversation_history = []
                for msg in st.session_state.messages[-6:]:  # Last 3 exchanges
                    if msg["role"] == "user":
                        conversation_history.append({"role": "user", "content": msg["content"]})
                    else:
                        conversation_history.append({"role": "assistant", "content": msg["content"]})
                
                # Generate response
                response = st.session_state.character_manager.generate_response(
                    character_id=st.session_state.current_character,
                    user_message=prompt,
                    conversation_history=conversation_history[:-1]  # Exclude current message
                )
                
                st.markdown(response)
                st.session_state.messages.append({"role": "assistant", "content": response})
                
            except Exception as e:
                error_msg = f"❌ Error: {str(e)}"
                st.error(error_msg)
                st.session_state.messages.append({"role": "assistant", "content": error_msg})