using multi turn

src/streamlit_app.py

@@ -2,14 +2,15 @@ import streamlit as st
 import requests
 import os
 
-# Load your OpenRouter API key
+# === Constants ===
 OPENROUTER_API_KEY = os.getenv("OPENROUTER_API_KEY") or st.secrets.get("OPENROUTER_API_KEY", "")
 MODEL_NAME = "deepseek/deepseek-r1-0528:free"
+API_URL = "https://openrouter.ai/api/v1/chat/completions"
 
-# App title
-st.title("WhatsApp-like Chat with DeepSeek-R1")
+# === Streamlit UI Setup ===
+st.title("💬 Chat with DeepSeek-R1 (Free via OpenRouter)")
 
-# Custom CSS
+# Custom WhatsApp-style CSS
 st.markdown("""
 <style>
     .stChatMessage { background-color: transparent !important; padding: 0 !important; width: 100%; }
@@ -29,35 +30,28 @@ st.markdown("""
 </style>
 """, unsafe_allow_html=True)
 
-# Initialize chat history
+# === Chat History ===
 if "messages" not in st.session_state:
     st.session_state.messages = [{"role": "system", "content": "You are a helpful assistant."}]
 
-# Display chat messages
-for message in st.session_state.messages:
-    if message["role"] == "system":
+# === Display Chat History ===
+for msg in st.session_state.messages:
+    if msg["role"] == "system":
         continue
-    with st.chat_message(message["role"]):
-        if message["role"] == "user":
-            st.markdown(f"""
-            <div class="user-container">
-                <div class="user-label sender-label">You:</div>
-                <div class="user-message">{message['content']}</div>
-            </div>
-            """, unsafe_allow_html=True)
-        else:
-            st.markdown(f"""
-            <div class="assistant-container">
-                <div class="assistant-label sender-label">Bot:</div>
-                <div class="assistant-message">{message['content']}</div>
-            </div>
-            """, unsafe_allow_html=True)
+    with st.chat_message(msg["role"]):
+        content_html = f"""
+        <div class="{msg['role']}-container">
+            <div class="{msg['role']}-label sender-label">{'You' if msg['role']=='user' else 'Bot'}:</div>
+            <div class="{msg['role']}-message">{msg['content']}</div>
+        </div>
+        """
+        st.markdown(content_html, unsafe_allow_html=True)
 
-# Input field
+# === User Input ===
 if prompt := st.chat_input("Type your message..."):
+    # Add user message
     st.session_state.messages.append({"role": "user", "content": prompt})
-    
-    # Show user message immediately
+
     with st.chat_message("user"):
         st.markdown(f"""
         <div class="user-container">
@@ -66,7 +60,6 @@ if prompt := st.chat_input("Type your message..."):
         </div>
         """, unsafe_allow_html=True)
 
-    # Show assistant reply placeholder
     with st.chat_message("assistant"):
         placeholder = st.empty()
         placeholder.markdown("""
@@ -76,28 +69,28 @@ if prompt := st.chat_input("Type your message..."):
         </div>
         """, unsafe_allow_html=True)
 
-        # Call OpenRouter
-        headers = {
-            "Authorization": f"Bearer {OPENROUTER_API_KEY}",
-            "Content-Type": "application/json",
-            "HTTP-Referer": "https://your-app-name.streamlit.app/",
-            "X-Title": "DeepSeek WhatsApp Chat"
-        }
+        # === OpenRouter API Call ===
+        try:
+            headers = {
+                "Authorization": f"Bearer {OPENROUTER_API_KEY}",
+                "Content-Type": "application/json",
+                "HTTP-Referer": "https://your-app-name.streamlit.app/",  # required for free tier
+                "X-Title": "Streamlit WhatsApp Chatbot"
+            }
+            payload = {
+                "model": MODEL_NAME,
+                "messages": st.session_state.messages,
+                "stream": False
+            }
 
-        body = {
-            "model": MODEL_NAME,
-            "messages": st.session_state.messages,
-            "stream": False  # OpenRouter's free models might not support streaming
-        }
+            response = requests.post(API_URL, headers=headers, json=payload)
+            response.raise_for_status()
+            full_response = response.json()["choices"][0]["message"]["content"]
 
-        try:
-            res = requests.post("https://openrouter.ai/api/v1/chat/completions", headers=headers, json=body)
-            res.raise_for_status()
-            full_response = res.json()["choices"][0]["message"]["content"]
         except Exception as e:
-            full_response = f"Error: {str(e)}"
+            full_response = f"Error: {e}"
 
-        # Render final response
+        # Display and store assistant message
         placeholder.markdown(f"""
         <div class="assistant-container">
             <div class="assistant-label sender-label">Bot:</div>
@@ -105,5 +98,4 @@ if prompt := st.chat_input("Type your message..."):
         </div>
         """, unsafe_allow_html=True)
 
-        # Save assistant reply
         st.session_state.messages.append({"role": "assistant", "content": full_response})