Upload app.py

app.py

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+import sys
+import os
+import logging
+from typing import AsyncIterator
+
+from agents import (Runner, set_default_openai_key, trace)
+from openai.types.responses import ResponseTextDeltaEvent
+import streamlit as st
+
+from backend import lichtblick_agent
+
+# ====================
+# Setup logging
+# ====================
+logging.basicConfig(
+    level=logging.INFO,
+    format="%(asctime)s | %(levelname)s | %(name)s | %(message)s"
+)
+logger = logging.getLogger("Lichtblick")
+
+# ============================
+# Core async function
+# ============================
+async def llm_response(api_key: str, message: str) -> AsyncIterator[str]:
+    """
+    Streams the response from the Lichtblick assistant as an async text generator.
+
+    Args:
+        api_key (str): The OpenAI API key to authenticate requests.
+        message (str): The user's input message to be processed by the agent.
+
+    Yields:
+        str: Incremental chunks of the assistant's response text as they are streamed.
+    """
+    set_default_openai_key(api_key)
+    if not api_key or not api_key.startswith("sk-"):
+        logger.error("Missing or invalid OpenAI API key.")
+        yield "🤖 API key is missing or invalid. Please check your .env file."
+        return
+
+    # Construct context from message history
+    context = ""
+    for msg in st.session_state.messages[-5:]:  # Use last 5 turns
+        role = "User" if msg["role"] == "user" else "Assistant"
+        content = msg["content"]
+        context += f"{role}: {content}\n\n"  # Double newline for clarity
+    context += f"User: {message}"
+
+    try:
+        result = Runner.run_streamed(lichtblick_agent, input=message)
+        async for event in result.stream_events():
+            if event.type == "raw_response_event" and isinstance(event.data, ResponseTextDeltaEvent):
+                if event.data.delta:
+                    yield event.data.delta
+        logger.info("Agent streaming complete.")
+    except Exception as e:
+        logger.exception("Error during agent processing.")
+        yield "🤖 Sorry, something went wrong. Please try again."
+
+# ============================
+# Lichtblick Streamlit App
+# ============================
+st.set_page_config(
+    page_title="Lichtblick", 
+    page_icon="🇩🇪📚", 
+    layout="centered", 
+    initial_sidebar_state="collapsed"
+)
+
+# Sidebar
+with st.sidebar:
+    st.image("assets/lichtblick_mascot.png")
+    openai_api_key = st.sidebar.text_input("OpenAI API Key", type="password")
+
+    # ✅ Show "ready" toast only once per session
+    if openai_api_key and openai_api_key.startswith("sk-"):
+        if not st.session_state.get("api_key_validated"):
+            st.toast("💡 Lichtblick is ready!", icon="✅")
+            st.session_state.api_key_validated = True
+    elif openai_api_key:
+        st.toast("❌ Invalid API key format.", icon="⚠️")
+        st.session_state.api_key_validated = False
+
+    # Clear chat + reset session
+    # 🧹 Centered Clear Chat Button in the sidebar
+    st.markdown("<div style='text-align: center;'>", unsafe_allow_html=True)
+    if st.button("🧹 Clear Chat", use_container_width=True):
+        st.session_state.messages = []
+        st.session_state.api_key_validated = False
+        st.toast("🧹 Chat history cleared!", icon="✅")
+    st.markdown("</div>", unsafe_allow_html=True)
+
+
+# App title
+st.title("💡:blue[_Lichtblick_] :orange[_Assistant_]💡")
+
+# Short Description
+with st.expander("ℹ️ What is Lichtblick?"):
+    st.markdown("Lichtblick is your smart and supportive assistant for learning German through sentence analysis, vocabulary help, and clear explanations.")
+
+
+# Initialize chat history
+if "messages" not in st.session_state:
+    st.session_state.messages = []
+
+# Display chat messages from history
+for message in st.session_state.messages:
+    with st.chat_message(message["role"]):
+        st.markdown(message["content"])
+
+# Accept user input
+if user_input := st.chat_input("Ready to learn German? Ask me anything!"):
+    if not openai_api_key or not openai_api_key.startswith("sk-"):
+        st.toast("❌ Please enter a valid OpenAI API key.", icon="⚠️")
+        st.stop()
+
+    elif user_input.strip() == "":
+        st.toast("⚠️ Please enter a message.", icon="⚠️")
+
+    else:
+        # Add user message to chat history
+        st.session_state.messages.append({"role": "user", "content": user_input})
+
+        with st.chat_message("user", avatar="🤵🏻"):
+            st.markdown(user_input)
+
+        with st.chat_message("assistant", avatar="🤖"):
+            try:
+                with st.spinner("💬 Lichtblick is thinking..."):
+                    with trace("Lichtblick workflow"):
+                        response = st.write_stream(llm_response(api_key=openai_api_key, message=user_input))
+                st.session_state.messages.append({"role": "assistant", "content": response})
+            except Exception as e:
+                logger.exception("Exception in response streaming.")
+                st.toast("🤖 Oops! Something went wrong while processing your request.", icon="❌")