Update app.py

app.py

@@ -13,12 +13,12 @@ import google.generativeai as genai
 warnings.filterwarnings("ignore")
 
 # ==========================================
-# 👇 API KEYS SETUP 👇
+# 👇 API KEYS SETUP 👇
 # ==========================================
 keys_string = os.environ.get("API_KEYS", "")
 API_KEYS = [k.strip() for k in keys_string.replace(',', ' ').replace('\n', ' ').split() if k.strip()]
 
-# --- 💾 DATABASE ---
+# --- 💾 DATABASE ---
 DB_FILE = "chat_db.json"
 def load_db():
     try:
@@ -35,33 +35,42 @@ user_db = load_db()
 current_key_index = 0
 app = Flask(__name__)
 
-# --- 🧠 SYSTEM INSTRUCTION ---
-BASE_INSTRUCTION = """
+# --- 🧠 SYSTEM INSTRUCTION ---
+SYSTEM_INSTRUCTION = """
 ROLE: You are "Student's AI", a professional academic tutor.
 RULES:
 1. **MATH:** Use LaTeX for formulas ($$ ... $$).
 2. **DIAGRAMS:** Use Mermaid.js (```mermaid ... ```).
 3. **LANGUAGE:** English by default. Use Tamil/Tanglish ONLY if requested.
 4. **FORMAT:** Markdown. Bold key terms.
+5. **CODE:** Use Python/Java/C++ blocks. Explain logic briefly.
 """
 
-# --- 🧬 MODEL FUNCTIONS ---
+# --- 🧬 MODEL & FILE HANDLING ---
 def get_working_model(key):
     try:
         genai.configure(api_key=key)
-        return 'gemini-1.5-flash'
+        models = list(genai.list_models())
+        chat_models = [m for m in models if 'generateContent' in m.supported_generation_methods]
+        for m in chat_models:
+            if "flash" in m.name.lower() and "1.5" in m.name: return m.name
+        for m in chat_models:
+            if "pro" in m.name.lower() and "1.5" in m.name: return m.name
+        if chat_models: return chat_models[0].name
     except: return None
+    return None
 
 def process_image(image_data):
     try:
-        if "base64," in image_data: image_data = image_data.split("base64,")[1]
+        if "base64," in image_data:
+            image_data = image_data.split("base64,")[1]
         image_bytes = base64.b64decode(image_data)
         return Image.open(io.BytesIO(image_bytes))
     except: return None
 
-def generate_with_retry(prompt, image_data=None, file_text=None, history_messages=[], user_context=""):
+def generate_with_retry(prompt, image_data=None, file_text=None, history_messages=[]):
     global current_key_index
-    if not API_KEYS: return "🚨 API Keys Missing."
+    if not API_KEYS: return "🚨 API Keys Missing."
 
     formatted_history = []
     for m in history_messages[-6:]:
@@ -69,141 +78,254 @@ def generate_with_retry(prompt, image_data=None, file_text=None, history_message
         formatted_history.append({"role": role, "parts": [m["content"]]})
 
     current_parts = []
-    full_prompt = prompt
-    if user_context:
-        full_prompt = f"[Context: Student is studying {user_context}]\nQuestion: {prompt}"
-
     if file_text: current_parts.append(f"analyzing file:\n{file_text}\n\n")
-    current_parts.append(full_prompt)
+    current_parts.append(prompt)
     if image_data:
         img = process_image(image_data)
         if img: current_parts.append(img)
 
     for i in range(len(API_KEYS)):
         key = API_KEYS[current_key_index]
+        model_name = get_working_model(key)
+        
+        if not model_name:
+            current_key_index = (current_key_index + 1) % len(API_KEYS)
+            continue
+
         try:
             genai.configure(api_key=key)
-            model = genai.GenerativeModel(model_name='gemini-1.5-flash', system_instruction=BASE_INSTRUCTION)
-            if image_data or file_text: response = model.generate_content(current_parts)
+            model = genai.GenerativeModel(model_name=model_name, system_instruction=SYSTEM_INSTRUCTION)
+            
+            if image_data or file_text:
+                response = model.generate_content(current_parts)
             else:
                 chat = model.start_chat(history=formatted_history)
-                response = chat.send_message(full_prompt)
+                response = chat.send_message(prompt)
             return response.text
         except Exception as e:
             current_key_index = (current_key_index + 1) % len(API_KEYS)
             time.sleep(1)
-    return "⚠️ System Busy. Please try again."
 
-# --- UI TEMPLATE ---
+    return "⚠️ System Busy. Please try again."
+
+# --- UI TEMPLATE (Fixed Quotes & Logic) ---
 HTML_TEMPLATE = """
 <!DOCTYPE html>
 <html lang="en">
 <head>
     <meta charset="UTF-8">
-    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no, interactive-widget=resizes-content">
+    <meta name="mobile-web-app-capable" content="yes">
+    <meta name="apple-mobile-web-app-capable" content="yes">
+    <meta name="theme-color" content="#09090b">
+    <link rel="manifest" href="/manifest.json">
     <title>Student's AI</title>
+    
     <link href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/6.4.0/css/all.min.css" rel="stylesheet">
     <link href="https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;600;700&family=JetBrains+Mono:wght@400;500&display=swap" rel="stylesheet">
+    
     <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/styles/atom-one-dark.min.css">
     <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.9.0/highlight.min.js"></script>
     <script src="https://cdn.jsdelivr.net/npm/marked/marked.min.js"></script>
     <script>window.MathJax = { tex: { inlineMath: [['$', '$']] }, svg: { fontCache: 'global' } };</script>
     <script src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
+    <script type="module">
+      import mermaid from 'https://cdn.jsdelivr.net/npm/mermaid@10/dist/mermaid.esm.min.mjs';
+      mermaid.initialize({ startOnLoad: false, theme: 'dark', securityLevel: 'loose' });
+      window.mermaid = mermaid;
+    </script>
 
     <style>
-        :root { --bg: #09090b; --card: #18181b; --user-msg: #27272a; --text: #e4e4e7; --border: #27272a; --dim: #71717a; }
-        body { margin: 0; background: var(--bg); color: var(--text); font-family: 'Outfit', sans-serif; height: 100dvh; overflow: hidden; }
+        :root {
+            --bg: #09090b; --card: #18181b; --user-msg: #27272a; --text: #e4e4e7;
+            --accent: #fff; --border: #27272a; --dim: #71717a;
+        }
+        * { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }
         
-        /* HEADER */
-        header { height: 70px; padding: 0 20px; background: rgba(9,9,11, 0.98); border-bottom: 1px solid var(--border); display: flex; align-items: center; justify-content: space-between; position: absolute; top: 0; width: 100%; z-index: 50; }
-        .app-title { font-size: 24px; font-weight: 800; color: #fff; }
-        .menu-btn { width: 40px; height: 40px; border-radius: 50%; border: 1px solid #333; display: flex; align-items: center; justify-content: center; cursor: pointer; color:#fff; }
-        .settings-icon { font-size: 18px; color: #aaa; cursor: pointer; }
-
-        /* MAIN CONTAINER */
-        #app-container { display: flex; flex-direction: column; height: 100dvh; padding-top: 70px; }
-        #chat-box { flex: 1; overflow-y: auto; padding: 20px 5%; padding-bottom: 80px; display: flex; flex-direction: column; gap: 20px; }
+        body, html { 
+            margin: 0; padding: 0; height: 100dvh; width: 100%; max-width: 100%;
+            background: var(--bg); color: var(--text); font-family: 'Outfit', sans-serif; 
+            overflow: hidden; font-size: 17px;
+            -webkit-user-select: none; user-select: none;
+        }
+
+        textarea, input { -webkit-user-select: text !important; user-select: text !important; }
+        .user-content, .ai-content, code, pre { -webkit-user-select: none !important; user-select: none !important; }
+
+        /* --- APP CONTAINER (Pushed down for Header) --- */
+        #app-container { 
+            display: flex; flex-direction: column; 
+            height: 100dvh; width: 100%; 
+            position: relative; overflow-x: hidden;
+            padding-top: 70px; /* Space for fixed header */
+        }
+
+        /* --- HEADER LOCKED --- */
+        header {
+            height: 70px; padding: 0 20px; background: rgba(9,9,11, 0.98);
+            border-bottom: 1px solid var(--border-color);
+            display: flex; align-items: center; justify-content: space-between; 
+            z-index: 50;
+            padding-top: env(safe-area-inset-top);
+            position: absolute; top: 0; left: 0; right: 0;
+        }
+        .menu-btn {
+            width: 40px; height: 40px; border-radius: 50%; border: 1px solid #333;
+            display: flex; align-items: center; justify-content: center; cursor: pointer;
+            transition: 0.2s; color: #fff;
+        }
+        .menu-btn:active { transform: scale(0.95); background: #222; }
+        .app-title { font-size: 24px; font-weight: 800; letter-spacing: -0.5px; color: #fff; }
+
+        /* --- SIDEBAR ANIMATION --- */
+        #sidebar {
+            position: fixed; top: 0; left: 0; width: 100%; height: 100%; 
+            background: var(--bg); z-index: 100; 
+            display: flex; flex-direction: column; padding: 25px;
+            padding-top: calc(70px + env(safe-area-inset-top));
+            transform: translateY(-100%);
+            transition: transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
+            overflow-y: auto;
+        }
+        #sidebar.open { transform: translateY(0); }
+        
+        @media (min-width: 768px) {
+            #sidebar { width: 350px; border-right: 1px solid var(--border); }
+            .input-container { max-width: 800px; }
+            #chat-box { padding: 20px 15%; }
+        }
+
+        .user-info { margin-bottom: 30px; font-size: 20px; font-weight: 700; color: #fff; display: flex; align-items: center; gap: 15px; flex-shrink: 0; }
+        .new-chat-btn {
+            width: 100%; padding: 15px; background: #fff; color: #000; border: none; 
+            border-radius: 12px; font-weight: 700; font-size: 16px; cursor: pointer; margin-bottom: 25px; flex-shrink: 0;
+        }
         
-        /* OVERLAYS (LOGIN & SELECTION) - FORCE VISIBILITY HANDLED BY JS */
-        .overlay { position: fixed; inset: 0; background: #000; z-index: 2000; display: flex; align-items: flex-start; justify-content: center; padding-top: 150px; transition: opacity 0.3s; }
-        .overlay.hidden { display: none !important; opacity: 0; pointer-events: none; }
+        .history-label { color: var(--dim); font-size: 13px; font-weight: 600; margin-bottom: 10px; letter-spacing: 1px; text-transform: uppercase; flex-shrink: 0; }
+        #history-list { flex: 1; overflow-y: auto; padding: 10px 0; min-height: 100px; }
         
-        .login-box { width: 90%; max-width: 350px; text-align: center; padding: 30px; border: 1px solid var(--border); border-radius: 20px; background: #0a0a0a; }
+        .history-item { 
+            display: flex; justify-content: space-between; align-items: center;
+            padding: 15px; margin-bottom: 12px; background: var(--card); border: 1px solid var(--border); border-radius: 12px;
+            cursor: pointer; color: #a1a1aa; font-size: 15px; transition: 0.2s;
+        }
+        .history-item:active { background: #222; color: #fff; border-color: #444; }
+        .h-title { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; max-width: 200px; flex: 1; margin-right: 10px; }
+        .h-actions { display: none; gap: 15px; }
+        .history-item.active-mode .h-actions { display: flex; }
+        .h-icon { font-size: 16px; color: #fff; padding: 5px; }
         
-        /* FORM ELEMENTS */
-        .form-label { display: block; text-align: left; font-size: 12px; color: #aaa; margin-bottom: 5px; margin-top: 15px; }
-        input, select { width: 100%; padding: 12px; margin-bottom: 5px; background: #18181b; border: 1px solid #333; color: #fff; border-radius: 8px; outline: none; font-size: 16px; font-family: 'Outfit', sans-serif; }
-        .start-btn { width: 100%; padding: 15px; border-radius: 12px; border: none; background: #fff; font-weight: 800; cursor: pointer; font-size: 16px; margin-top: 25px; }
+        .rename-input {
+            background: transparent; border: none; border-bottom: 1px solid #fff;
+            color: #fff; font-family: 'Outfit', sans-serif; font-size: 15px;
+            width: 100%; outline: none; padding: 0;
+        }
+
+        .brand-section { text-align: center; margin-top: 20px; padding-bottom: env(safe-area-inset-bottom); flex-shrink: 0; }
+        .brand-name { font-family: 'Outfit', sans-serif; font-weight: 600; font-size: 12px; color: var(--dim); letter-spacing: 2px; margin-bottom: 10px; opacity: 0.6; }
+        .logout-btn { color: #ef4444; cursor: pointer; font-size: 15px; font-weight: 600; padding: 10px; }
 
-        /* MESSAGES */
-        .msg { display: flex; flex-direction: column; opacity: 0; animation: fadeInstant 0.3s forwards; }
+        #chat-box {
+            flex: 1; overflow-y: auto; padding: 20px 5%; padding-bottom: 80px; 
+            display: flex; flex-direction: column; gap: 25px;
+            -webkit-overflow-scrolling: touch; overscroll-behavior-y: contain; min-height: 0; 
+        }
+        
+        /* --- LOCKED INTRO TEXT --- */
+        #intro-container {
+            position: absolute;
+            top: 140px; /* Fixed from top so it won't move up with keyboard */
+            left: 50%;
+            transform: translateX(-50%);
+            width: 90%; max-width: 600px;
+            text-align: center;
+            z-index: 10;
+            pointer-events: none;
+        }
+
+        .msg { width: 100%; line-height: 1.7; font-size: 17px; opacity: 0; animation: fadeInstant 0.3s forwards; display: flex; flex-direction: column; }
         @keyframes fadeInstant { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }
+
         .user-msg { align-items: flex-end; }
-        .user-content { background: var(--user-msg); padding: 10px 16px; border-radius: 18px 18px 4px 18px; max-width: 85%; color: #fff; }
+        .user-content { display: inline-block; width: fit-content; max-width: 85%; background: var(--user-msg); padding: 10px 16px; border-radius: 18px 18px 4px 18px; text-align: left; color: #fff; word-wrap: break-word; }
+        
         .ai-msg { align-items: flex-start; }
-        .ai-content { width: 100%; color: #d4d4d8; }
-        .ai-content strong { color: #fff; }
-
-        /* INPUT AREA */
-        .input-wrapper { background: var(--bg); padding: 15px; border-top: 1px solid var(--border); }
+        .ai-content { width: 100%; color: #d4d4d8; word-wrap: break-word; }
+        .ai-content strong { color: #fff; font-weight: 700; }
+        .ai-content h1, .ai-content h2 { margin-top: 20px; color: #fff; font-weight: 700; }
+        .ai-content img, .user-content img { cursor: pointer; transition: 0.2s; }
+        .ai-content img:active, .user-content img:active { transform: scale(0.98); }
+
+        pre { background: #1e1e1e !important; border-radius: 12px; padding: 15px; overflow-x: auto; margin: 15px 0; border: 1px solid #333; max-width: 100%; }
+        code { font-family: 'JetBrains Mono', monospace; font-size: 14px; }
+        .mjx-chtml { background: #18181b; padding: 10px; border-radius: 8px; border: 1px solid #333; overflow-x: auto; margin: 10px 0; text-align: center; max-width: 100%; }
+        .mermaid { background: #111; padding: 15px; border-radius: 10px; text-align: center; margin: 15px 0; overflow-x: auto; }
+
+        .msg-actions { margin-top: 10px; opacity: 0; transition: opacity 0.2s; display: flex; gap: 20px; align-items: center; }
+        .user-msg .msg-actions { justify-content: flex-end; }
+        .msg:hover .msg-actions { opacity: 1; }
+        .action-icon { cursor: pointer; color: var(--dim); font-size: 18px; transition: 0.2s; }
+        .action-icon:hover { color: #fff; transform: scale(1.1); }
+
+        .input-wrapper { background: var(--bg); padding: 15px; border-top: 1px solid var(--border); flex-shrink: 0; z-index: 60; padding-bottom: max(15px, env(safe-area-inset-bottom)); }
         .input-container { max-width: 900px; margin: 0 auto; background: var(--card); border: 1px solid var(--border); border-radius: 24px; padding: 8px 12px; display: flex; align-items: flex-end; gap: 12px; }
         textarea { flex: 1; background: transparent; border: none; color: #fff; font-size: 17px; max-height: 120px; padding: 10px 5px; resize: none; outline: none; font-family: 'Outfit', sans-serif; }
-        .icon-btn, .send-btn { width: 38px; height: 38px; display: flex; align-items: center; justify-content: center; border-radius: 50%; border: none; cursor: pointer; font-size: 18px; }
-        .icon-btn { background: transparent; color: #a1a1aa; }
-        .send-btn { background: #fff; color: #000; }
-
-        /* SIDEBAR */
-        #sidebar { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: var(--bg); z-index: 100; padding: 25px; padding-top: 80px; transform: translateY(-100%); transition: transform 0.4s; }
-        #sidebar.open { transform: translateY(0); }
-        
-        /* INTRO */
-        #intro-container { position: absolute; top: 140px; left: 50%; transform: translateX(-50%); width: 90%; max-width: 600px; text-align: center; pointer-events: none; z-index: 10; }
+        .icon-btn { width: 38px; height: 38px; display: flex; align-items: center; justify-content: center; border-radius: 50%; border: none; background: transparent; color: #a1a1aa; cursor: pointer; font-size: 18px; }
+        .send-btn { background: #fff; color: #000; width: 38px; height: 38px; border-radius: 50%; border: none; display: flex; align-items: center; justify-content: center; cursor: pointer; font-size: 18px; }
+
+        #preview-area { position: absolute; bottom: 85px; left: 20px; display: none; z-index: 70; }
+        .preview-box { width: 60px; height: 60px; border-radius: 12px; border: 2px solid #fff; background: #222; overflow: hidden; position: relative; box-shadow: 0 4px 12px rgba(0,0,0,0.5); }
+        .preview-img { width: 100%; height: 100%; object-fit: cover; }
+        .remove-preview { position: absolute; top: -8px; right: -8px; background: red; color: white; border-radius: 50%; width: 20px; height: 20px; font-size: 12px; cursor: pointer; border: none; display: flex; align-items: center; justify-content: center; }
+
+        /* --- LOGIN PAGE LOCKED (FIXED) --- */
+        #login-overlay { 
+            position: fixed; inset: 0; background: #000; z-index: 2000; 
+            display: flex; 
+            /* Align to START (Top) to prevent centering jump */
+            align-items: flex-start; justify-content: center;
+            /* Force padding from top so it never moves */
+            padding-top: 180px; 
+            transition: opacity 0.8s ease; opacity: 1; pointer-events: auto;
+        }
+        #login-overlay.hidden { opacity: 0; pointer-events: none; }
         
-        #preview-area { display:none; position:absolute; bottom:85px; left:20px; }
-        .preview-box { width:60px; height:60px; background:#222; border:2px solid #fff; border-radius:12px; overflow:hidden; }
-        .preview-img { width:100%; height:100%; object-fit:cover; }
+        .login-box { 
+            width: 90%; max-width: 350px; text-align: center; 
+            padding: 40px; border: 1px solid var(--border); border-radius: 20px; background: #0a0a0a; 
+            /* No auto margins */
+        }
+
+        #image-modal { position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.9); z-index: 3000; display: none; align-items: center; justify-content: center; opacity: 0; transition: opacity 0.3s; }
+        #image-modal img { max-width: 95%; max-height: 90%; border-radius: 8px; box-shadow: 0 0 20px rgba(0,0,0,0.8); }
+        #image-modal.active { opacity: 1; }
     </style>
 </head>
 <body>
 
-    <div id="login-overlay" class="overlay">
+    <div id="login-overlay">
         <div class="login-box">
             <h1 class="app-title" style="margin-bottom:10px;">Student's AI</h1>
-            <input type="text" id="username-input" placeholder="Your Name">
-            <button class="start-btn" onclick="handleLogin()">Next</button>
+            <input type="text" id="username-input" placeholder="Your Name" style="width:100%; padding:15px; border-radius:12px; border:1px solid #333; background:#111; color:#fff; text-align:center; outline:none; margin-bottom:20px; font-size: 16px;" onkeydown="if(event.key==='Enter') handleLogin()">
+            <button onclick="handleLogin()" style="width:100%; padding:15px; border-radius:12px; border:none; background:#fff; font-weight:800; cursor:pointer; font-size: 16px;">Start Learning</button>
         </div>
     </div>
 
-    <div id="selection-overlay" class="overlay hidden">
-        <div class="login-box">
-            <h2 style="color:#fff; margin-top:0;">Customize Profile</h2>
-            
-            <span class="form-label">Education Level</span>
-            <select id="edu-level" onchange="updateEduOptions()">
-                <option value="school">School (6th - 12th)</option>
-                <option value="college">College (Arts/Engg)</option>
-            </select>
-
-            <span class="form-label">Class / Year</span>
-            <select id="edu-year"></select>
-
-            <span class="form-label">Subject (Optional)</span>
-            <input type="text" id="edu-subject" placeholder="Ex: Maths, Physics...">
-
-            <button class="start-btn" onclick="handleSelection()">Start Learning</button>
-        </div>
+    <div id="image-modal" onclick="closeImagePreview()">
+        <img id="modal-img" src="" alt="Preview">
     </div>
 
     <div id="sidebar">
-        <div style="display:flex; justify-content:space-between; align-items:center; margin-bottom:20px;">
-            <div style="font-size:20px; font-weight:700; color:#fff;">Hi <span id="display-name">User</span></div>
+        <div style="display:flex; justify-content:space-between; align-items:center; margin-bottom:20px; flex-shrink:0;">
+            <div class="user-info"><span id="display-name">User</span></div>
             <div class="menu-btn" onclick="toggleSidebar()"><i class="fas fa-times"></i></div>
         </div>
-        <button class="start-btn" style="margin:0 0 20px 0; padding:12px;" onclick="newChat()">New Chat</button>
-        <div style="color:#71717a; font-size:13px; font-weight:600; text-transform:uppercase;">Chat History</div>
-        <div id="history-list" style="margin-top:10px;"></div>
-        <div style="position:absolute; bottom:30px; width:100%; left:0; text-align:center;">
-             <div style="color:#ef4444; cursor:pointer; font-weight:600;" onclick="handleLogout()">Log Out</div>
+        <button class="new-chat-btn" onclick="newChat()">New Chat</button>
+        <div class="history-label">Chat History</div>
+        <div id="history-list"></div>
+        <div class="brand-section">
+            <div class="brand-name">Designed by Shirpi</div>
+            <div class="logout-btn" onclick="handleLogout()">Log Out</div>
         </div>
     </div>
 
@@ -211,20 +333,26 @@ HTML_TEMPLATE = """
         <header>
             <div class="menu-btn" onclick="toggleSidebar()"><i class="fas fa-bars"></i></div>
             <span class="app-title">Student's AI</span>
-            <div class="settings-icon" onclick="openSettings()"><i class="fas fa-cog"></i></div>
+            <div style="width:40px;"></div>
         </header>
 
         <div id="chat-box"></div>
 
         <div class="input-wrapper">
-             <div id="preview-area">
-                <div class="preview-box"><img id="preview-img" class="preview-img"></div>
-                <button onclick="clearAttachment()" style="background:red; color:white; border:none; border-radius:50%; width:20px; height:20px; position:absolute; top:-5px; right:-5px;">×</button>
+            <div id="preview-area">
+                <div class="preview-box"><div id="preview-visual"></div></div>
+                <button class="remove-preview" onclick="clearAttachment()">×</button>
             </div>
+            
             <div class="input-container">
                 <button class="icon-btn" onclick="document.getElementById('file-input').click()"><i class="fas fa-paperclip"></i></button>
-                <input type="file" id="file-input" hidden onchange="handleFile(this)">
-                <textarea id="input" placeholder="Type a message..." rows="1" oninput="this.style.height='auto';this.style.height=this.scrollHeight+'px'"></textarea>
+                <input type="file" id="file-input" accept="image/*,.txt,.py,.js,.html,.css,.md,.csv,.json" hidden onchange="handleFileSelect(this)">
+                
+                <button class="icon-btn" onclick="document.getElementById('camera-input').click()"><i class="fas fa-camera"></i></button>
+                <input type="file" id="camera-input" accept="image/*" capture="environment" hidden onchange="handleFileSelect(this)">
+                
+                <textarea id="input" placeholder="Type a message..." rows="1" oninput="resizeInput(this)"></textarea>
+                
                 <button class="send-btn" onclick="send()"><i class="fas fa-arrow-up"></i></button>
             </div>
         </div>
@@ -233,178 +361,306 @@ HTML_TEMPLATE = """
     <script>
         let currentUser = null;
         let currentChatId = null;
-        let userContext = "";
-        let currentAttachment = null;
-
+        let currentAttachment = { type: null, data: null, name: null };
+        let longPressTimer;
+        
+        // --- FIXED INTRO: LOCKED CONTAINER ---
         function getIntroHtml(name) {
-            return `<div id="intro-container"><div class="msg ai-msg"><div class="ai-content"><h1>Hi ${name},</h1><p>Ready to master ${userContext ? userContext.split(',')[0] : "studies"}?</p></div></div></div>`;
+            return `<div id="intro-container"><div class="msg ai-msg"><div class="ai-content"><h1>Hi ${name},</h1><p>Ready to master your studies today?</p></div></div></div>`;
         }
 
-        // --- AUTH LOGIC (ROBUST FIX) ---
+        // --- AUTH LOGIC (SMOOTH TRANSITION) ---
         function checkLogin() {
-            const u = localStorage.getItem("student_ai_user");
-            const c = localStorage.getItem("student_ai_context");
-            if(u) {
-                currentUser = u;
-                document.getElementById('login-overlay').style.display = 'none';
-                if(c) {
-                    userContext = c;
-                    document.getElementById('selection-overlay').style.display = 'none';
-                    showApp();
-                } else {
-                    document.getElementById('selection-overlay').classList.remove('hidden'); 
-                    updateEduOptions();
+            try {
+                const stored = localStorage.getItem("student_ai_user");
+                if (stored) { 
+                    currentUser = stored; 
+                    document.getElementById("login-overlay").classList.add('hidden'); 
+                    showApp(); 
                 }
-            }
+            } catch(e) { console.log("Storage access denied"); }
         }
-
+        
         function handleLogin() {
-            const name = document.getElementById("username-input").value.trim();
-            if(!name) { alert("Please enter a name"); return; }
-            
-            localStorage.setItem("student_ai_user", name);
-            currentUser = name;
-
-            // FORCE DISPLAY CHANGE
-            document.getElementById("login-overlay").style.display = 'none';
-            const sel = document.getElementById("selection-overlay");
-            sel.style.display = 'flex';
-            sel.classList.remove('hidden');
-            sel.style.opacity = '1';
-            
-            updateEduOptions();
-        }
-
-        function updateEduOptions() {
-            const level = document.getElementById('edu-level').value;
-            const yearSelect = document.getElementById('edu-year');
-            yearSelect.innerHTML = "";
-            let opts = level === 'school' ? ["6th", "7th", "8th", "9th", "10th", "11th", "12th"] : ["1st Year", "2nd Year", "3rd Year", "4th Year"];
-            opts.forEach(o => {
-                let op = document.createElement('option');
-                op.value = o; op.innerText = o;
-                yearSelect.appendChild(op);
-            });
+            const input = document.getElementById("username-input");
+            const name = input.value.trim();
+            if(name) { 
+                try { localStorage.setItem("student_ai_user", name); } catch(e){}
+                currentUser = name; 
+                // FORCE HIDE DIRECTLY
+                const overlay = document.getElementById("login-overlay");
+                overlay.classList.add('hidden');
+                setTimeout(() => overlay.style.display = 'none', 500); 
+                showApp(); 
+            } else {
+                input.style.border = "1px solid red"; 
+                setTimeout(() => input.style.border = "1px solid #333", 2000);
+            }
         }
-
-        function handleSelection() {
-            const l = document.getElementById('edu-level').value;
-            const y = document.getElementById('edu-year').value;
-            const s = document.getElementById('edu-subject').value;
-            userContext = `${l}, ${y}, ${s}`;
-            localStorage.setItem("student_ai_context", userContext);
-            document.getElementById('selection-overlay').style.display = 'none';
-            showApp();
+        function handleLogout() { 
+            try { localStorage.removeItem("student_ai_user"); } catch(e){}
+            const overlay = document.getElementById("login-overlay");
+            overlay.style.display = 'flex';
+            setTimeout(() => overlay.classList.remove('hidden'), 10);
+            document.getElementById('sidebar').classList.remove('open');
+            setTimeout(() => {
+                document.getElementById('chat-box').innerHTML = "";
+                currentChatId = null;
+                document.getElementById("username-input").value = "";
+            }, 500);
         }
-
+        
         function showApp() {
-            document.getElementById('display-name').innerText = currentUser;
+            document.getElementById("display-name").innerText = "Hi " + currentUser;
             loadHistory();
-            if(!currentChatId && !document.getElementById('intro-container')) {
-                document.getElementById('chat-box').innerHTML = getIntroHtml(currentUser);
+            if(!currentChatId) {
+                const box = document.getElementById("chat-box");
+                if(box.innerHTML === "") {
+                    box.innerHTML = getIntroHtml(currentUser);
+                }
             }
         }
 
-        function handleLogout() {
-            localStorage.clear();
-            location.reload();
-        }
-
-        function openSettings() {
-            const sel = document.getElementById("selection-overlay");
-            sel.style.display = 'flex';
-            sel.classList.remove('hidden');
-            sel.style.opacity = '1';
+        function resizeInput(el) {
+            el.style.height = 'auto';
+            el.style.height = Math.min(el.scrollHeight, 150) + 'px';
         }
 
-        function toggleSidebar() { document.getElementById('sidebar').classList.toggle('open'); }
-
-        function handleFile(input) {
-            if(input.files[0]) {
+        function handleFileSelect(input) {
+            if (input.files && input.files[0]) {
+                const file = input.files[0];
                 const reader = new FileReader();
-                reader.onload = (e) => {
-                    currentAttachment = e.target.result;
-                    document.getElementById('preview-area').style.display = 'block';
-                    document.getElementById('preview-img').src = currentAttachment;
-                };
-                reader.readAsDataURL(input.files[0]);
+                reader.onload = function(e) {
+                    const result = e.target.result;
+                    const isImage = file.type.startsWith('image/');
+                    currentAttachment = { type: isImage ? 'image' : 'file', data: isImage ? result : atob(result.split(',')[1]), name: file.name };
+                    const previewArea = document.getElementById('preview-area');
+                    const visual = document.getElementById('preview-visual');
+                    previewArea.style.display = 'block';
+                    visual.innerHTML = isImage ? `<img src="${result}" class="preview-img">` : `<div class="preview-file-icon"><i class="fas fa-file-alt"></i></div>`;
+                }
+                reader.readAsDataURL(file);
             }
+            input.value = "";
         }
+
         function clearAttachment() {
-            currentAttachment = null;
+            currentAttachment = { type: null, data: null, name: null };
             document.getElementById('preview-area').style.display = 'none';
-            document.getElementById('file-input').value = "";
+        }
+
+        function scrollToBottom() {
+            const box = document.getElementById('chat-box');
+            setTimeout(() => {
+                box.scrollTo({ top: box.scrollHeight, behavior: 'smooth' });
+            }, 100);
         }
 
         async function send() {
-            const txt = document.getElementById('input').value.trim();
-            if(!txt && !currentAttachment) return;
+            const input = document.getElementById('input');
+            const text = input.value.trim();
+            if (!text && !currentAttachment.data) return;
 
+            // --- REMOVE INTRO TEXT AUTOMATICALLY ---
             const intro = document.getElementById('intro-container');
-            if(intro) intro.remove();
-
-            const box = document.getElementById('chat-box');
-            let imgHtml = currentAttachment ? `<br><img src="${currentAttachment}" style="max-height:100px;border-radius:8px;">` : "";
-            box.insertAdjacentHTML('beforeend', `<div class="msg user-msg"><div class="user-content">${txt}${imgHtml}</div></div>`);
+            if(intro) { intro.style.display = 'none'; intro.remove(); }
+
+            const chatBox = document.getElementById('chat-box');
+            let attachHtml = '';
+            if (currentAttachment.type === 'image') attachHtml = `<br><img src="${currentAttachment.data}" style="max-height:100px; margin-top:10px; border-radius:8px;">`;
+            if (currentAttachment.type === 'file') attachHtml = `<br><small>📄 ${currentAttachment.name}</small>`;
+
+            const userHtml = `
+                <div class="msg user-msg">
+                    <div class="user-content">${text.replace(/</g, "&lt;")}${attachHtml}</div>
+                    <div class="msg-actions">
+                         <i class="fas fa-copy action-icon" onclick="copyText('${text}')"></i>
+                         <i class="fas fa-pen action-icon" onclick="editMessage('${text}')"></i>
+                    </div>
+                </div>`;
+            chatBox.insertAdjacentHTML('beforeend', userHtml);
             
-            document.getElementById('input').value = "";
-            let imgData = currentAttachment;
+            const promptText = text;
+            const imgData = currentAttachment.type === 'image' ? currentAttachment.data : null;
+            const fileText = currentAttachment.type === 'file' ? currentAttachment.data : null;
+
+            input.value = ''; input.style.height = 'auto';
             clearAttachment();
-            box.scrollTo(0, box.scrollHeight);
+            scrollToBottom();
 
             const msgId = "ai-" + Date.now();
-            box.insertAdjacentHTML('beforeend', `<div id="${msgId}" class="msg ai-msg">...</div>`);
-            
+            chatBox.insertAdjacentHTML('beforeend', `<div id="${msgId}" class="msg ai-msg"><i class="fas fa-circle-notch fa-spin"></i></div>`);
+            scrollToBottom();
+
             try {
-                if(!currentChatId) {
+                if (!currentChatId) {
                     const r = await fetch('/new_chat', {method:'POST', headers:{'Content-Type':'application/json'}, body:JSON.stringify({username:currentUser})});
                     const d = await r.json(); currentChatId = d.chat_id;
+                    loadHistory();
                 }
                 const res = await fetch('/chat', {
-                    method:'POST', headers:{'Content-Type':'application/json'},
-                    body:JSON.stringify({message:txt, image:imgData, username:currentUser, chat_id:currentChatId, user_context:userContext})
+                    method: 'POST', headers: {'Content-Type': 'application/json'},
+                    body: JSON.stringify({ message: promptText, image: imgData, file_text: fileText, username: currentUser, chat_id: currentChatId })
                 });
                 const data = await res.json();
-                document.getElementById(msgId).innerHTML = `<div class="ai-content">${marked.parse(data.response)}</div>`;
-                hljs.highlightAll();
-                box.scrollTo(0, box.scrollHeight);
+                
+                const aiDiv = document.getElementById(msgId);
+                aiDiv.innerHTML = ""; 
+                const contentDiv = document.createElement('div');
+                contentDiv.className = 'ai-content';
+                aiDiv.appendChild(contentDiv);
+
+                await typeWriter(contentDiv, data.response);
+
+                aiDiv.insertAdjacentHTML('beforeend', `
+                    <div class="msg-actions">
+                        <i class="fas fa-copy action-icon" onclick="copyAiResponse(this)"></i>
+                        <i class="fas fa-share-alt action-icon" onclick="shareResponse(this)"></i>
+                        <i class="fas fa-redo action-icon" onclick="regenerate('${promptText}')"></i>
+                    </div>`);
+
+                scrollToBottom();
                 if(data.new_title) loadHistory();
-            } catch(e) { document.getElementById(msgId).innerText = "Error."; }
+            } catch (e) { document.getElementById(msgId).innerHTML = "⚠️ Error: " + e.message; }
+        }
+
+        function copyText(text) { navigator.clipboard.writeText(text); }
+        function copyAiResponse(btn) {
+            const text = btn.closest('.ai-msg').querySelector('.ai-content').innerText;
+            navigator.clipboard.writeText(text);
+        }
+        function shareResponse(btn) {
+            const text = btn.closest('.ai-msg').querySelector('.ai-content').innerText;
+            if (navigator.share) navigator.share({ title: 'Student AI', text: text });
+            else navigator.clipboard.writeText(text);
+        }
+        function editMessage(oldText) { document.getElementById('input').value = oldText; document.getElementById('input').focus(); }
+        function regenerate(text) { document.getElementById('input').value = text; send(); }
+        
+        document.getElementById('chat-box').addEventListener('click', function(e) {
+            if(e.target.tagName === 'IMG') {
+                const modal = document.getElementById('image-modal');
+                const modalImg = document.getElementById('modal-img');
+                modalImg.src = e.target.src;
+                modal.style.display = 'flex';
+                setTimeout(() => modal.classList.add('active'), 10);
+            }
+        });
+        function closeImagePreview() {
+            const modal = document.getElementById('image-modal');
+            modal.classList.remove('active');
+            setTimeout(() => modal.style.display = 'none', 300);
         }
 
+        function handleHistoryTouchStart(e, cid) {
+            longPressTimer = setTimeout(() => {
+                e.target.closest('.history-item').classList.add('active-mode');
+            }, 600);
+        }
+        function handleHistoryTouchEnd(e) { clearTimeout(longPressTimer); }
+        
+        function startRename(cid) {
+            const item = document.getElementById('chat-' + cid);
+            const titleSpan = item.querySelector('.h-title');
+            const currentTitle = titleSpan.innerText;
+            const input = document.createElement('input');
+            input.type = 'text'; input.value = currentTitle; input.className = 'rename-input';
+            
+            async function save() {
+                const newTitle = input.value.trim();
+                if(newTitle && newTitle !== currentTitle) {
+                    await fetch('/rename_chat', {
+                        method:'POST', headers:{'Content-Type':'application/json'}, 
+                        body:JSON.stringify({username:currentUser, chat_id:cid, title:newTitle})
+                    });
+                    loadHistory();
+                } else { loadHistory(); }
+            }
+            input.addEventListener('blur', save);
+            input.addEventListener('keydown', (e) => { if(e.key === 'Enter') { input.blur(); } });
+            titleSpan.replaceWith(input); input.focus();
+        }
+
+        async function deleteChat(cid) {
+            const el = document.getElementById('chat-' + cid);
+            if(el) el.remove();
+            await fetch('/delete_chat', {
+                method:'POST', headers:{'Content-Type':'application/json'}, 
+                body:JSON.stringify({username:currentUser, chat_id:cid})
+            });
+            if(currentChatId === cid) newChat(); 
+            loadHistory();
+        }
+            
         async function loadHistory() {
-             try {
+            try {
                 const res = await fetch('/get_history', {method:'POST', headers:{'Content-Type':'application/json'}, body:JSON.stringify({username:currentUser})});
                 const data = await res.json();
                 const list = document.getElementById('history-list'); list.innerHTML = "";
-                Object.keys(data.chats).reverse().forEach(cid => {
-                    list.innerHTML += `<div style="padding:10px; margin-bottom:5px; background:#18181b; border-radius:8px; cursor:pointer;" onclick="loadChat('${cid}')">${data.chats[cid].title || "Chat"}</div>`;
-                });
-            } catch(e){}
+                if (data.chats) {
+                    Object.keys(data.chats).reverse().forEach(cid => {
+                        const title = data.chats[cid].title || "New Chat";
+                        list.innerHTML += `
+                        <div class="history-item" id="chat-${cid}" onclick="loadChat('${cid}')" oncontextmenu="return false;"
+                             ontouchstart="handleHistoryTouchStart(event, '${cid}')" ontouchend="handleHistoryTouchEnd(event)">
+                            <span class="h-title">${title}</span>
+                            <div class="h-actions">
+                                <i class="fas fa-pen h-icon" onclick="event.stopPropagation(); startRename('${cid}')"></i>
+                                <i class="fas fa-trash h-icon" onclick="event.stopPropagation(); deleteChat('${cid}')"></i>
+                            </div>
+                        </div>`;
+                    });
+                }
+            } catch(e) {}
         }
 
+        async function typeWriter(element, markdownText) {
+            element.innerHTML = marked.parse(markdownText);
+            hljs.highlightAll(); 
+            if (window.MathJax) await MathJax.typesetPromise([element]);
+            if (window.mermaid) {
+                 const m = element.querySelectorAll('code.language-mermaid');
+                 m.forEach(c => { const d = document.createElement('div'); d.className='mermaid'; d.innerHTML=c.innerText; c.parentElement.replaceWith(d); });
+                 window.mermaid.init(undefined, element.querySelectorAll('.mermaid'));
+            }
+            element.style.opacity = 0; element.style.transition = 'opacity 0.4s';
+            setTimeout(() => { element.style.opacity = 1; scrollToBottom(); }, 50);
+        }
+
+        function toggleSidebar() { document.getElementById('sidebar').classList.toggle('open'); }
+        async function newChat() {
+            currentChatId = null; 
+            document.getElementById('chat-box').innerHTML = getIntroHtml(currentUser);
+            const r = await fetch('/new_chat', {method:'POST', headers:{'Content-Type':'application/json'}, body:JSON.stringify({username:currentUser})});
+            const d = await r.json(); currentChatId = d.chat_id; loadHistory();
+            document.getElementById('sidebar').classList.remove('open');
+        }
         async function loadChat(cid) {
-            currentChatId = cid;
-            const res = await fetch('/get_chat', {method:'POST', headers:{'Content-Type':'application/json'}, body:JSON.stringify({username:currentUser, chat_id:cid})});
-            const data = await res.json();
-            const box = document.getElementById('chat-box'); box.innerHTML = "";
-            data.messages.forEach(m => {
-                let cls = m.role === 'user' ? 'user' : 'ai';
-                let content = m.role === 'user' ? m.content : marked.parse(m.content);
-                box.insertAdjacentHTML('beforeend', `<div class="msg ${cls}-msg"><div class="${cls}-content">${content}</div></div>`);
+            currentChatId = cid; const res = await fetch('/get_chat', {method:'POST', headers:{'Content-Type':'application/json'}, body:JSON.stringify({username:currentUser, chat_id:cid})});
+            const data = await res.json(); const box = document.getElementById('chat-box'); box.innerHTML = "";
+            data.messages.forEach(msg => {
+                const isUser = msg.role === 'user';
+                if(isUser) {
+                    box.insertAdjacentHTML('beforeend', `<div class="msg user-msg"><div class="user-content">${msg.content.replace(/</g, "&lt;")}</div></div>`);
+                } else {
+                    const div = document.createElement('div'); div.className = 'msg ai-msg';
+                    div.innerHTML = `<div class="ai-content">${marked.parse(msg.content)}</div>`;
+                    box.appendChild(div);
+                    hljs.highlightAll();
+                    if(window.MathJax) MathJax.typesetPromise([div]);
+                    div.insertAdjacentHTML('beforeend', `<div class="msg-actions"><i class="fas fa-copy action-icon" onclick="copyAiResponse(this)"></i></div>`);
+                }
             });
             document.getElementById('sidebar').classList.remove('open');
-            hljs.highlightAll();
+            box.scrollTop = box.scrollHeight;
         }
 
-        // Init
         checkLogin();
     </script>
 </body>
 </html>
 """
-
-# --- ROUTES ---
+# --- BACKEND ROUTES ---
 @app.route("/", methods=["GET"])
 def home(): return render_template_string(HTML_TEMPLATE)
 
@@ -417,6 +673,24 @@ def new_chat():
     save_db(user_db)
     return jsonify({"chat_id": nid})
 
+@app.route("/rename_chat", methods=["POST"])
+def rename_chat():
+    d = request.json
+    u, cid, t = d.get("username"), d.get("chat_id"), d.get("title")
+    if u in user_db and cid in user_db[u]:
+        user_db[u][cid]["title"] = t
+        save_db(user_db)
+    return jsonify({"status":"ok"})
+
+@app.route("/delete_chat", methods=["POST"])
+def delete_chat():
+    d = request.json
+    u, cid = d.get("username"), d.get("chat_id")
+    if u in user_db and cid in user_db[u]:
+        del user_db[u][cid]
+        save_db(user_db)
+    return jsonify({"status":"ok"})
+
 @app.route("/get_history", methods=["POST"])
 def get_history():
     u = request.json.get("username")
@@ -430,22 +704,49 @@ def get_chat():
 @app.route("/chat", methods=["POST"])
 def chat():
     d = request.json
-    u, cid, msg, ctx = d.get("username"), d.get("chat_id"), d.get("message"), d.get("user_context", "")
-    img = d.get("image")
-    
+    u, cid, msg = d.get("username"), d.get("chat_id"), d.get("message")
+    img_data = d.get("image")
+    file_text = d.get("file_text")
+
     if u not in user_db: user_db[u] = {}
     if cid not in user_db[u]: user_db[u][cid] = {"messages": []}
-    
+
     user_db[u][cid]["messages"].append({"role": "user", "content": msg})
-    reply = generate_with_retry(msg, img, None, user_db[u][cid]["messages"][:-1], ctx)
+    reply = generate_with_retry(msg, img_data, file_text, user_db[u][cid]["messages"][:-1])
     user_db[u][cid]["messages"].append({"role": "model", "content": reply})
     
     new_title = False
     if len(user_db[u][cid]["messages"]) <= 2:
         user_db[u][cid]["title"] = " ".join(msg.split()[:4])
         new_title = True
+        
     save_db(user_db)
     return jsonify({"response": reply, "new_title": new_title})
 
+@app.route('/manifest.json')
+def manifest():
+    data = {
+        "name": "Student's AI",
+        "short_name": "Student's AI",
+        "start_url": "/",
+        "display": "standalone",
+        "orientation": "portrait",
+        "background_color": "#09090b",
+        "theme_color": "#09090b",
+        "icons": [
+            {
+                "src": "https://huggingface.co/spaces/Shirpi/Student-s_AI/resolve/main/1000177401.png", 
+                "sizes": "192x192",
+                "type": "image/png"
+            },
+            {
+                "src": "https://huggingface.co/spaces/Shirpi/Student-s_AI/resolve/main/1000177401.png",
+                "sizes": "512x512",
+                "type": "image/png"
+            }
+        ]
+    }
+    return Response(json.dumps(data), mimetype='application/json')
+
 if __name__ == '__main__':
     app.run(host='0.0.0.0', port=7860)