Update app.py

app.py

@@ -1,31 +1,42 @@
 import streamlit as st
 import requests
-# Backend URL - handle both local and Hugging Face deployment
-# For Hugging Face Spaces
 import os
 
-# Check if running on Hugging Face
-HF_SPACE = os.environ.get("SPACE_ID") is not None
+# ============== BACKEND URL CONFIGURATION ==============
+# For Hugging Face deployment
+import socket
 
-if HF_SPACE:
-    # On Hugging Face, backend runs on same container but different port
-    BACKEND_URL = "http://localhost:8000"
-    # OR use the public URL of your space
-    # space_name = os.environ.get("SPACE_ID")
-    # BACKEND_URL = f"https://{space_name}.hf.space"
-else:
-    # Local development
-    BACKEND_URL = "http://localhost:8000"
+def get_backend_url():
+    """Determine backend URL based on environment."""
+    # Check if we're on Hugging Face
+    if os.environ.get("SPACE_ID"):
+        # On Hugging Face, backend is on localhost:8000
+        return "http://localhost:8000"
+    else:
+        # Local development
+        return "http://localhost:8000"
+
+BACKEND_URL = get_backend_url()
+# ======================================================
 
 st.set_page_config(page_title="PDF Assistant", page_icon="📘", layout="wide")
 
+# Test backend connection on startup
+try:
+    health_check = requests.get(f"{BACKEND_URL}/health", timeout=2)
+    if health_check.status_code == 200:
+        st.sidebar.success("✅ Backend connected")
+    else:
+        st.sidebar.warning(f"⚠️ Backend status: {health_check.status_code}")
+except:
+    st.sidebar.error("❌ Cannot connect to backend")
+
 # ---------------- CSS (Dark Theme) ----------------
-# FIX: Added CSS for the footer
 st.markdown("""
 <style>
 /* Streamlit standard setup for dark theme adherence */
 :root {
-    --primary-color: #1e3a8a; /* Blue for highlights */
+    --primary-color: #1e3a8a;
     --background-color: #0e1117;
     --secondary-background-color: #1a1d29;
     --text-color: #f0f2f6;
@@ -33,22 +44,22 @@ st.markdown("""
 
 /* Custom Chat Bubbles */
 .chat-user {
-    background: #2d3748; /* Dark gray */
+    background: #2d3748;
     padding: 12px;
-    border-radius: 10px 10px 2px 10px; /* Rounded corners for chat bubble */
+    border-radius: 10px 10px 2px 10px;
     margin: 6px 0 6px auto;
     max-width: 85%;
     text-align: right;
     color: var(--text-color);
 }
 .chat-bot {
-    background: var(--primary-color); /* Primary blue */
+    background: var(--primary-color);
     padding: 12px;
     border-radius: 10px 10px 10px 2px;
     margin: 6px auto 6px 0;
     max-width: 85%;
     text-align: left;
-    color: #ffffff; /* White text for contrast */
+    color: #ffffff;
 }
 
 /* Sources section styling */
@@ -81,6 +92,13 @@ st.markdown("""
 .footer a:hover {
     text-decoration: underline;
 }
+
+/* Debug info */
+.debug-info {
+    font-size: 0.7em;
+    color: #888;
+    margin-top: 5px;
+}
 </style>
 """, unsafe_allow_html=True)
 
@@ -91,32 +109,27 @@ if "chat" not in st.session_state:
 if "uploaded_file_name" not in st.session_state:
     st.session_state.uploaded_file_name = None
 
-# Add a key to the file uploader to allow it to be reset.
 if "uploader_key" not in st.session_state:
     st.session_state.uploader_key = 0
 
-# FIX 1: Change application name
-st.title("📘 PDF Assistant")
-
+# Show backend URL for debugging
+st.sidebar.markdown(f"**Backend URL:** `{BACKEND_URL}`", unsafe_allow_html=True)
 
 # ---------------- FUNCTIONS ----------------
 def clear_chat_history():
-    """Clears the chat history in the session state."""
     st.session_state.chat = []
 
-
 def clear_memory():
-    """Calls the backend endpoint to clear loaded PDF data and resets UI state."""
-    res = requests.post(f"{BACKEND_URL}/clear")
-    if res.status_code == 200:
-        st.session_state.uploaded_file_name = None
-        # Increment the key of the file uploader to clear its value
-        st.session_state.uploader_key += 1
-        st.success("Memory cleared. Please upload a new PDF.")
-    else:
-        st.error(f"Failed to clear memory: {res.json().get('detail', 'Unknown error')}")
-    # Removed st.rerun() to prevent "no-op" warning
-
+    try:
+        res = requests.post(f"{BACKEND_URL}/clear")
+        if res.status_code == 200:
+            st.session_state.uploaded_file_name = None
+            st.session_state.uploader_key += 1
+            st.success("Memory cleared. Please upload a new PDF.")
+        else:
+            st.error(f"Failed to clear memory: {res.json().get('detail', 'Unknown error')}")
+    except Exception as e:
+        st.error(f"Error clearing memory: {str(e)}")
 
 # ---------------- SIDEBAR CONTROLS ----------------
 with st.sidebar:
@@ -130,18 +143,19 @@ with st.sidebar:
     else:
         st.warning("⬆️ Upload a PDF to start chatting!")
 
+# ---------------- MAIN APP ----------------
+st.title("📘 PDF Assistant")
+
 # ---------------- UPLOAD PDF ----------------
-# Use the dynamic key for the file uploader.
 uploaded = st.file_uploader(
     "Upload your PDF",
     type=["pdf"],
-    key=st.session_state.uploader_key # Use the dynamic key
+    key=st.session_state.uploader_key
 )
 
-# Only process if a file is uploaded AND it's a NEW file
 if uploaded and uploaded.name != st.session_state.uploaded_file_name:
-    st.session_state.uploaded_file_name = None  # Clear status while processing
-    st.session_state.chat = []  # Clear chat for a new document
+    st.session_state.uploaded_file_name = None
+    st.session_state.chat = []
 
     with st.spinner(f"Processing '{uploaded.name}'..."):
         try:
@@ -150,25 +164,24 @@ if uploaded and uploaded.name != st.session_state.uploaded_file_name:
 
             if res.status_code == 200:
                 chunks = res.json().get("chunks", 0)
-                st.success(f"PDF processed successfully! {chunks} chunks created.")
+                st.success(f"✅ PDF processed successfully! {chunks} chunks created.")
                 st.session_state.uploaded_file_name = uploaded.name
+                st.markdown(f'<div class="debug-info">Backend: {BACKEND_URL}, Status: {res.status_code}</div>', unsafe_allow_html=True)
             else:
-                error_msg = res.json().get("detail", "Unknown error during processing.")
-                st.error(f"Upload failed: {error_msg}")
+                error_msg = res.json().get("detail", f"HTTP {res.status_code}")
+                st.error(f"❌ Upload failed: {error_msg}")
                 st.session_state.uploaded_file_name = None
 
         except requests.exceptions.ConnectionError:
-            st.error(f"Could not connect to the backend server at {BACKEND_URL}. Ensure it is running.")
+            st.error(f"🔌 Could not connect to backend at {BACKEND_URL}")
             st.session_state.uploaded_file_name = None
         except Exception as e:
-            st.error(f"An unexpected error occurred: {e}")
+            st.error(f"⚠️ Unexpected error: {str(e)}")
             st.session_state.uploaded_file_name = None
 
-    # Rerun the app to update the UI status immediately
     st.rerun()
 
 # ---------------- CHAT INPUT ----------------
-# Disable input field if no PDF is loaded
 disabled_input = st.session_state.uploaded_file_name is None
 question = st.text_input(
     "Ask a question about the loaded PDF:",
@@ -177,10 +190,8 @@ question = st.text_input(
 )
 
 if st.button("Send", disabled=disabled_input) and question:
-    # 1. Add user query to chat history
     st.session_state.chat.append(("user", question))
 
-    # 2. Call backend
     with st.spinner("Thinking..."):
         try:
             res = requests.post(f"{BACKEND_URL}/ask", json={"question": question})
@@ -190,40 +201,33 @@ if st.button("Send", disabled=disabled_input) and question:
                 answer = data.get("answer", "No answer provided.")
                 sources = data.get("sources", 0)
 
-                # Format the bot's response to include source count
                 bot_message = f"{answer}<div class='sources'>Context Chunks Used: {sources}</div>"
                 st.session_state.chat.append(("bot", bot_message))
+                st.markdown(f'<div class="debug-info">Backend: {BACKEND_URL}, Status: {res.status_code}</div>', unsafe_allow_html=True)
 
             else:
-                error_detail = res.json().get("detail", "Error while generating answer.")
+                error_detail = res.json().get("detail", f"HTTP {res.status_code}")
                 st.session_state.chat.append(("bot", f"🔴 **Error:** {error_detail}"))
 
         except requests.exceptions.ConnectionError:
-            st.session_state.chat.append(("bot",
-                                          f"🔴 **Error:** Could not connect to the backend server at {BACKEND_URL}. Ensure it is running."))
+            st.session_state.chat.append(("bot", f"🔴 **Error:** Could not connect to backend at {BACKEND_URL}"))
         except Exception as e:
-            st.session_state.chat.append(("bot", f"🔴 **An unexpected error occurred:** {e}"))
+            st.session_state.chat.append(("bot", f"🔴 **Unexpected error:** {str(e)}"))
 
-    # Rerun to display the updated chat history
     st.rerun()
 
 # ---------------- SHOW CHAT HISTORY ----------------
 st.markdown("## Chat History")
-# Reverse the list to show the latest messages at the bottom
 for role, msg in st.session_state.chat:
     if role == "user":
         st.markdown(f"<div class='chat-user'>{msg}</div>", unsafe_allow_html=True)
     else:
-        # Bot message includes the source count, so use the HTML content
         st.markdown(f"<div class='chat-bot'>{msg}</div>", unsafe_allow_html=True)
 
-# ---------------- FOOTER (Creator Credit) ----------------
-# FIX 2: Add creator credit with LinkedIn link
+# ---------------- FOOTER ----------------
 footer_html = """
 <div class="footer">
     Created by <a href="https://www.linkedin.com/in/abhishek-iitr/" target="_blank">Abhishek Saxena</a>
 </div>
 """
-st.markdown(footer_html, unsafe_allow_html=True)
-
-# ---------------- END ----------------
+st.markdown(footer_html, unsafe_allow_html=True)