Update app.py

app.py

@@ -1,168 +1,99 @@
 import streamlit as st
 import google.generativeai as genai
-from google.generativeai import types
-
-# --- CONFIGURATION ---
-# Task 3: Use Case Adaptation (Academic Tutor)
-APP_TITLE = "🧠 Academic Tutor Assistant powered by Gemini"
-DEFAULT_SYSTEM_PROMPT = (
-    "You are an expert **Academic Tutor**. Your goal is to help the user understand complex "
-    "concepts, review essays, solve problems, and provide study guidance. "
-    "Respond with clear, structured, and encouraging explanations. "
-    "Always ask a follow-up question to encourage deeper learning."
-)
 
-# --- HELPER FUNCTIONS ---
+# -------------------
+# API Key Setup
+# -------------------
+gemini_api_key = st.secrets.get("GEN_API_KEY", "")
 
-@st.cache_resource(show_spinner="Connecting to Gemini...")
-def setup_gemini_client(api_key):
-    """Initializes and configures the Gemini client."""
-    if not api_key:
-        st.error("⚠️ Please set your 'GEN_API_KEY' in Streamlit secrets.")
-        st.stop()
-    try:
-        genai.configure(api_key=api_key)
-        return genai
-    except Exception as e:
-        st.error(f"⚠️ Error configuring Gemini client: {e}")
-        st.stop()
+# -------------------
+# Page Configuration
+# -------------------
+st.set_page_config(page_title="Your AI Buddy", layout="wide")
+st.title("💡 Need answers? Just type below!")
 
+# -------------------
+# Gemini Setup
+# -------------------
+if not gemini_api_key:
+    st.error("⚠️ Please set your 'GEN_API_KEY' in Streamlit secrets.")
+    st.stop()
 
-def get_available_models():
-    """Fetches and filters available chat-capable models."""
-    try:
-        available_models = [
-            m.name for m in genai.list_models()
-            if "generateContent" in m.supported_generation_methods
-            and ("gemini-2.5" in m.name or "gemini-1.5" in m.name) # Filter for high-quality models
-        ]
-        if not available_models:
-            st.error("⚠️ No suitable Gemini models available for your API key.")
-            st.stop()
-        return available_models
-    except Exception as e:
-        st.error(f"⚠️ Error fetching models: {e}")
-        st.stop()
+genai.configure(api_key=gemini_api_key)
 
+# Fetch available Gemini models
+available_models = [
+    m.name for m in genai.list_models()
+    if "generateContent" in m.supported_generation_methods
+]
 
-def init_chat_session(model_name, system_prompt):
-    """Initializes a new Gemini chat session with a system instruction."""
+if not available_models:
+    st.error("⚠️ No Gemini models available for your API key.")
+    st.stop()
+
+# Reset session if old model is invalid
+if "model" in st.session_state and st.session_state["model"] not in available_models:
+    del st.session_state["model"]
+
+model = st.sidebar.selectbox("Model", available_models, index=0)
+
+# Initialize Gemini chat if needed
+if "gemini_chat" not in st.session_state or st.session_state.get("model") != model:
+    st.session_state.model = model
     try:
-        # Task 2: Proper System Prompt Injection via config
-        config = types.GenerateContentConfig(
-            system_instruction=system_prompt
-        )
-        gemini_model = genai.GenerativeModel(model_name)
-        st.session_state.gemini_chat = gemini_model.start_chat(
-            history=[],
-            config=config  # Apply the system instruction here
-        )
+        gemini_model = genai.GenerativeModel(model)
+        st.session_state.gemini_chat = gemini_model.start_chat(history=[])
     except Exception as e:
-        st.error(f"⚠️ Could not initialize Gemini model '{model_name}': {e}")
+        st.error(f"⚠️ Could not initialize Gemini model: {e}")
         st.stop()
 
-# --- STREAMLIT PAGE SETUP ---
-
-# 1. Page Configuration (Task 4: UI Improvement)
-st.set_page_config(page_title=APP_TITLE, layout="wide", initial_sidebar_state="expanded")
-st.title(APP_TITLE)
-st.markdown(
-    "Ask any academic question, paste your homework problem, or submit a paragraph for review. Let's learn together!"
+# -------------------
+# System Prompt
+# -------------------
+system_prompt = st.sidebar.text_area(
+    "System Prompt",
+    "You are a helpful AI assistant. Provide concise and accurate answers."
 )
 
-# 2. API Key and Client Setup
-gemini_api_key = st.secrets.get("GEN_API_KEY", "")
-gemini_client = setup_gemini_client(gemini_api_key)
-
-
-# 3. Sidebar Controls (Task 4: Usability Enhancement)
-with st.sidebar:
-    st.header("⚙️ Settings")
-    
-    # Model Selection
-    available_models = get_available_models()
-    default_index = 0
-    if "gemini-2.5-flash" in available_models:
-        default_index = available_models.index("gemini-2.5-flash")
-
-    new_model = st.selectbox(
-        "Select Model", 
-        available_models, 
-        index=default_index,
-        key="_selected_model_name"
-    )
-    
-    # System Prompt (Task 3: Use Case Adaptation)
-    system_prompt_key = "_system_prompt_area"
-    system_prompt = st.text_area(
-        "Tutor Persona / System Instruction",
-        DEFAULT_SYSTEM_PROMPT,
-        height=180,
-        key=system_prompt_key
-    )
-
-    # Check for configuration change and re-initialize chat
-    if (st.session_state.get("model") != new_model) or \
-       (st.session_state.get("system_prompt") != system_prompt):
-        
-        # Save new values and re-initialize chat
-        st.session_state.model = new_model
-        st.session_state.system_prompt = system_prompt
-        st.session_state.messages = []
-        init_chat_session(new_model, system_prompt)
-        st.info("Tutor persona updated. Conversation restarted.")
-        
-    # Reset Conversation Button (Task 4: Usability Enhancement)
-    if st.button("🔄 Reset Conversation"):
-        st.session_state.messages = []
-        init_chat_session(st.session_state.model, st.session_state.system_prompt)
-        # Note: No st.rerun() needed due to Streamlit's natural flow
-
-# 4. Chat Initialization (First run check)
-if "gemini_chat" not in st.session_state:
-    st.session_state.model = new_model
-    st.session_state.system_prompt = system_prompt
+# -------------------
+# Chat History State
+# -------------------
+if "messages" not in st.session_state:
     st.session_state.messages = []
-    init_chat_session(new_model, system_prompt)
 
-# --- CHAT INTERACTION ---
+# Reset conversation button
+if st.sidebar.button("Reset Conversation"):
+    st.session_state.messages = []
+    gemini_model = genai.GenerativeModel(model)
+    st.session_state.gemini_chat = gemini_model.start_chat(history=[])
+    st.rerun()
 
-# 5. Display Chat Messages (Task 4: Visualization)
+# -------------------
+# Display Chat Messages
+# -------------------
 for msg in st.session_state.messages:
     with st.chat_message(msg["role"]):
         st.markdown(msg["content"])
 
-
-# 6. User Input (Task 4: Placeholder)
-if user_input := st.chat_input("Ask about history, math, or review your essay draft..."):
-    # 6a. Add and display user message
+# -------------------
+# User Input
+# -------------------
+if user_input := st.chat_input("Type your message..."):
+    # Show user message
+    st.chat_message("user").markdown(user_input)
     st.session_state.messages.append({"role": "user", "content": user_input})
-    with st.chat_message("user"):
-        st.markdown(user_input)
 
-    # 6b. Send message to Gemini
     try:
-        with st.spinner("💡 Tutor is thinking..."):
-            # The system prompt is in the config, so we only send the user's message.
-            response = st.session_state.gemini_chat.send_message(user_input, stream=True)
-            
-            # Display response chunks as they arrive (Streaming for better UX)
-            full_response = ""
-            with st.chat_message("assistant"):
-                message_placeholder = st.empty()
-                for chunk in response:
-                    full_response += chunk.text
-                    message_placeholder.markdown(full_response + "▌") 
-                message_placeholder.markdown(full_response) # Final rendering
-
-        bot_text = full_response
-
+        with st.spinner("Gemini is thinking..."):
+            # Prepend system prompt for context
+            full_input = f"{system_prompt}\n\nUser: {user_input}"
+            resp = st.session_state.gemini_chat.send_message(full_input)
+            bot_text = resp.text
     except Exception as e:
-        bot_text = f"⚠️ The tutor could not respond right now. Please try again. Error: {e}"
-        with st.chat_message("assistant"):
-            st.markdown(bot_text)
+        bot_text = f"⚠️ Gemini could not respond right now. Please try again. ({e})"
+
+    with st.chat_message("assistant"):
+        st.markdown(bot_text)
 
-    # 6c. Save assistant message
     st.session_state.messages.append({"role": "assistant", "content": bot_text})
-    
-    # Task 4: Removed st.rerun() for better stability.
+    st.rerun()