Update app.py

app.py

@@ -7,7 +7,7 @@ import time
 import urllib.parse
 import os
 import threading
-from fastapi import FastAPI, Request, Response, Cookie
+from fastapi import FastAPI, Request, Response, Cookie, BackgroundTasks
 from fastapi.responses import HTMLResponse, RedirectResponse, JSONResponse
 from typing import Optional
 
@@ -16,107 +16,119 @@ from typing import Optional
 # ==========================================
 CLIENT_ID    = "J4PNT5QI22-100" 
 SECRET_KEY   = "ABRSWC1PMR"
-# CHANGE THIS TO YOUR EXACT SPACE URL
+# IMPORTANT: Ensure this matches your Space URL exactly
 REDIRECT_URI = "https://topsecrettraders-depthchain.hf.space/callback" 
 
 CACHE_FILE = "nifty_master.json"
 
-# GLOBAL RAM CACHE (Served instantly to users)
-RAM_DB = []
-IS_LOADING = False
-
 app = FastAPI()
 
 # ==========================================
-# 2. HIGH-SPEED DATA ENGINE
+# 2. ROBUST DATA LOADER (THREAD SAFE)
 # ==========================================
 
-def background_worker():
-    """Runs on startup to load DB into RAM immediately."""
-    global RAM_DB, IS_LOADING
-    
-    # 1. Try loading from Disk first (Fastest)
-    if os.path.exists(CACHE_FILE):
-        try:
-            print(">>> [BOOT] Loading from Disk Cache...")
-            with open(CACHE_FILE, "r") as f:
-                RAM_DB = json.load(f)
-            print(f">>> [BOOT] Loaded {len(RAM_DB)} symbols from Disk.")
-        except:
-            pass
-
-    # 2. If RAM is empty or old, Download from NSE (Background)
-    if not RAM_DB:
-        refresh_database()
-
-def refresh_database():
-    """Downloads, Filters, and Saves Data (Heavy Operation)"""
-    global RAM_DB, IS_LOADING
-    if IS_LOADING: return
-    IS_LOADING = True
+# Global State
+SYSTEM_STATUS = {
+    "ready": False,
+    "message": "Booting..."
+}
+UPDATE_LOCK = threading.Lock()
+
+def update_master_db():
+    """
+    Runs in background. Downloads, filters, and saves JSON.
+    """
+    global SYSTEM_STATUS
     
-    print(">>> [UPDATE] Downloading Master CSV from Fyers...")
+    # Acquire lock to prevent multiple downloads
+    if not UPDATE_LOCK.acquire(blocking=False):
+        return # Already updating
+
     try:
-        headers = {"User-Agent": "Mozilla/5.0"}
+        SYSTEM_STATUS["message"] = "Downloading Fyers Master CSV..."
+        print(">>> [BG TASK] STARTING DOWNLOAD...")
+        
+        headers = {
+            "User-Agent": "Mozilla/5.0"
+        }
         url = "https://public.fyers.in/sym_details/NSE_FO.csv"
         
-        # Streamlined CSV parsing
+        # Stream read or chunks could be better, but pandas is easier for filtering
+        # On_bad_lines skips errors
         df = pd.read_csv(
             url, 
             usecols=[0, 1, 8, 9], 
             names=['Token', 'Desc', 'Expiry', 'Symbol'], 
             header=0,
+            on_bad_lines='skip',
             storage_options=headers
         )
         
-        # STRICT NIFTY FILTER (Keeps file tiny)
-        # Only keep rows containing 'NIFTY' and exclude unwanted indices
+        SYSTEM_STATUS["message"] = "Filtering NIFTY Data..."
+        
+        df['Symbol'] = df['Symbol'].astype(str)
+        df['Desc'] = df['Desc'].astype(str)
+        
+        # Strict Filter: KEEP NIFTY, REMOVE BANK/FIN/MID
         mask = (
-            df['Symbol'].str.contains('NIFTY', na=False) & 
-            ~df['Symbol'].str.contains('BANKNIFTY', na=False) & 
-            ~df['Symbol'].str.contains('FINNIFTY', na=False) & 
-            ~df['Symbol'].str.contains('MIDCPNIFTY', na=False)
+            df['Symbol'].str.contains('NIFTY') & 
+            ~df['Symbol'].str.contains('BANKNIFTY') & 
+            ~df['Symbol'].str.contains('FINNIFTY') & 
+            ~df['Symbol'].str.contains('MIDCPNIFTY')
         )
         df = df[mask]
 
         results = [{"s": "NSE:NIFTY50-INDEX", "e": 0, "k": 0}]
 
         for _, row in df.iterrows():
-            sym = str(row['Symbol'])
-            desc = str(row['Desc'])
-            try: exp = int(row['Expiry'])
-            except: exp = 0
+            sym = row['Symbol']
+            desc = row['Desc']
+            try:
+                exp = int(row['Expiry'])
+            except:
+                exp = 0
             
             strike = 0.0
+            
+            # Logic: Parse Strike from Desc (e.g., "NIFTY 23 JAN 21500 CE")
             if "CE" in sym or "PE" in sym:
                 parts = desc.strip().split(' ')
                 if len(parts) >= 2:
-                    val = parts[-2].replace('.', '', 1)
-                    if val.isdigit(): strike = float(parts[-2])
+                    val = parts[-2]
+                    val_clean = val.replace('.', '', 1)
+                    if val_clean.isdigit():
+                        strike = float(val)
             
             results.append({"s": sym, "e": exp, "k": strike})
 
-        # Save to Disk
+        # Save to disk
         with open(CACHE_FILE, "w") as f:
             json.dump(results, f)
-        
-        # Update RAM
-        RAM_DB = results
-        print(f">>> [UPDATE] Success. DB Size: {len(RAM_DB)}")
-        
+            
+        SYSTEM_STATUS["ready"] = True
+        SYSTEM_STATUS["message"] = "Ready"
+        print(f">>> [BG TASK] COMPLETE. Saved {len(results)} symbols.")
+
     except Exception as e:
-        print(f">>> [ERROR] Update failed: {e}")
-    
-    IS_LOADING = False
+        print(f">>> [BG TASK] ERROR: {e}")
+        SYSTEM_STATUS["message"] = f"Error: {str(e)}"
+    finally:
+        UPDATE_LOCK.release()
 
 @app.on_event("startup")
 def startup_event():
-    # Start the worker in a separate thread so the server starts INSTANTLY
-    t = threading.Thread(target=background_worker)
-    t.start()
+    # check if cache exists
+    if os.path.exists(CACHE_FILE):
+        SYSTEM_STATUS["ready"] = True
+        SYSTEM_STATUS["message"] = "Loaded from Cache"
+        print(">>> STARTUP: Cache found. System Ready.")
+    else:
+        # Start background thread immediately
+        thread = threading.Thread(target=update_master_db)
+        thread.start()
 
 # ==========================================
-# 3. API ROUTES
+# 3. ROUTES
 # ==========================================
 
 @app.get("/")
@@ -128,6 +140,7 @@ def home(access_token: Optional[str] = Cookie(None)):
             f"https://api-t1.fyers.in/api/v3/generate-authcode?"
             f"client_id={CLIENT_ID}&redirect_uri={enc_redirect}&response_type=code&state={state}"
         )
+        
         return HTMLResponse(f"""
         <div style="height:100vh; display:flex; flex-direction:column; justify-content:center; align-items:center; font-family:sans-serif; background:#f5f5f5;">
             <div style="background:white; padding:40px; border-radius:10px; box-shadow:0 10px 30px rgba(0,0,0,0.1); text-align:center;">
@@ -136,13 +149,14 @@ def home(access_token: Optional[str] = Cookie(None)):
             </div>
         </div>
         """)
+    
     return HTMLResponse(HTML_TEMPLATE)
 
 @app.get("/callback")
 def callback(auth_code: Optional[str] = None, code: Optional[str] = None):
     final_code = auth_code if auth_code else code
     if not final_code: return JSONResponse({"error": "No Code"})
-    
+
     app_id_hash = hashlib.sha256(f"{CLIENT_ID}:{SECRET_KEY}".encode()).hexdigest()
     resp = requests.post("https://api-t1.fyers.in/api/v3/validate-authcode", json={
         "grant_type": "authorization_code", "appIdHash": app_id_hash, "code": final_code
@@ -154,7 +168,8 @@ def callback(auth_code: Optional[str] = None, code: Optional[str] = None):
         response = RedirectResponse(url="/")
         response.set_cookie(key="access_token", value=full_token, httponly=True)
         return response
-    return HTMLResponse(f"Login Failed: {json.dumps(data)}")
+    else:
+        return HTMLResponse(f"Login Failed: {json.dumps(data)}")
 
 @app.get("/logout")
 def logout():
@@ -162,36 +177,41 @@ def logout():
     response.delete_cookie("access_token")
     return response
 
+# --- STATUS CHECK ---
 @app.get("/api/status")
-def check_status():
-    """Frontend polls this to see if data is ready."""
-    if not RAM_DB:
-        return JSONResponse({"status": "loading"})
-    return JSONResponse({"status": "ready", "count": len(RAM_DB)})
+def get_status():
+    return JSONResponse(SYSTEM_STATUS)
 
-@app.get("/api/db")
-def get_db():
-    """Returns the RAM cached DB instantly."""
-    return JSONResponse(RAM_DB)
+@app.get("/api/init")
+def get_master_data():
+    if not SYSTEM_STATUS["ready"]:
+        return JSONResponse({"s": "wait", "msg": SYSTEM_STATUS["message"]})
+    
+    # Load from disk
+    try:
+        with open(CACHE_FILE, "r") as f:
+            data = json.load(f)
+        return JSONResponse(data)
+    except:
+        return JSONResponse([])
 
 @app.get("/api/refresh")
-def force_refresh():
-    """Manual trigger to update DB."""
-    threading.Thread(target=refresh_database).start()
-    return JSONResponse({"status": "started"})
+def force_refresh(background_tasks: BackgroundTasks):
+    SYSTEM_STATUS["ready"] = False
+    SYSTEM_STATUS["message"] = "Refreshing..."
+    background_tasks.add_task(update_master_db)
+    return JSONResponse({"s": "ok"})
 
 @app.get("/api/depth")
-def get_depth(symbols: str, response: Response, access_token: Optional[str] = Cookie(None)):
-    if not access_token: return JSONResponse({"s": "error"}, status_code=401)
+def get_market_depth(symbols: str, response: Response, access_token: Optional[str] = Cookie(None)):
+    if not access_token: return JSONResponse(status_code=401, content={"s":"error"})
     
-    # Anti-Cache Headers
     response.headers["Cache-Control"] = "no-cache, no-store, must-revalidate"
-    response.headers["Pragma"] = "no-cache"
     response.headers["Expires"] = "0"
     
     url = f"https://api-t1.fyers.in/data/depth?symbol={symbols}&ohlcv_flag=1"
-    headers = {"Authorization": access_token}
-    return JSONResponse(requests.get(url, headers=headers).json())
+    resp = requests.get(url, headers={"Authorization": access_token})
+    return JSONResponse(content=resp.json())
 
 # ==========================================
 # 4. FRONTEND
@@ -202,7 +222,7 @@ HTML_TEMPLATE = """
 <html lang="en">
 <head>
     <meta charset="UTF-8">
-    <title>NIFTY FAST CHAIN</title>
+    <title>NIFTY PRO CHAIN</title>
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <link href="https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@500;800&family=Inter:wght@400;600;800&display=swap" rel="stylesheet">
     <style>
@@ -216,21 +236,14 @@ HTML_TEMPLATE = """
         * { box-sizing: border-box; }
         body { margin: 0; background: var(--bg); color: var(--text-main); font-family: 'Inter', sans-serif; height: 100vh; display: flex; flex-direction: column; overflow: hidden; }
 
-        /* Loader Overlay */
-        .overlay { position: fixed; top:0; left:0; width:100%; height:100%; background: #fff; z-index: 9999; display: flex; justify-content: center; align-items: center; flex-direction: column; gap: 15px; transition: opacity 0.5s; }
-        .spinner { width: 40px; height: 40px; border: 4px solid #f3f3f3; border-top: 4px solid var(--accent); border-radius: 50%; animation: spin 1s linear infinite; }
-        @keyframes spin { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }
-
-        /* Nav */
         .top-nav { padding: 0 20px; background: #fff; border-bottom: 1px solid var(--border); display: flex; align-items: center; justify-content: space-between; height: 60px; }
         .btn { background: #fff; border: 1px solid var(--border); padding: 8px 16px; font-size: 12px; border-radius: 6px; cursor: pointer; font-weight: 700; display: flex; gap: 8px; align-items: center; transition:0.2s; }
         .btn:hover { border-color: var(--accent); color: var(--accent); background:#f0f7ff; }
         
-        /* Layout */
         .grid-layout { display: flex; height: calc(100vh - 60px); }
-        .chain-panel { flex: 1; display: flex; flex-direction: column; }
+        .chain-panel { flex: 1; display: flex; flex-direction: column; position: relative; }
         .chain-header { display: grid; grid-template-columns: 1fr 180px 1fr; padding: 10px 0; background: #f8f9fa; border-bottom: 1px solid var(--border); font-size: 11px; font-weight: 700; text-align: center; color: var(--text-sub); }
-        .chain-body { flex: 1; overflow-y: auto; }
+        .chain-body { flex: 1; overflow-y: auto; background: #fff; }
         
         .row { display: grid; grid-template-columns: 1fr 180px 1fr; border-bottom: 1px solid #f0f0f0; height: 45px; align-items: center; font-family: 'JetBrains Mono'; font-size: 12px; }
         .row.atm { background: var(--atm-bg); border-top: 1px solid var(--accent); border-bottom: 1px solid var(--accent); }
@@ -245,24 +258,29 @@ HTML_TEMPLATE = """
         .fut-panel { width: 300px; background: var(--panel); border-left: 1px solid var(--border); display: flex; flex-direction: column; }
         .fut-card { padding: 15px; background: #fff; border-bottom: 1px solid var(--border); }
         .meter-bg { height: 6px; background: #eee; border-radius: 3px; display: flex; overflow: hidden; margin-top: 5px; }
-
-        /* Modal */
+        
         .modal { position: fixed; top:0; left:0; width:100%; height:100%; background: rgba(255,255,255,0.9); z-index: 1000; display: none; justify-content: center; align-items: center; }
         .modal-box { background: #fff; border: 1px solid #ccc; width: 400px; border-radius: 8px; box-shadow: 0 10px 30px rgba(0,0,0,0.1); padding: 20px; }
         .modal-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin-top: 15px; max-height: 50vh; overflow-y: auto; }
         .exp-btn { padding: 10px; text-align: center; border: 1px solid #eee; border-radius: 4px; cursor: pointer; }
+        .exp-btn:hover { background: #f0f7ff; border-color: var(--accent); }
         .exp-btn.active { background: var(--accent); color: white; }
         
+        /* LOADER OVERLAY */
+        .loader-ov { position: fixed; top:0; left:0; width:100%; height:100%; background:#fff; display:flex; flex-direction:column; justify-content:center; align-items:center; z-index: 9999; }
+        .spinner { width: 30px; height: 30px; border: 4px solid #f3f3f3; border-top: 4px solid var(--accent); border-radius: 50%; animation: spin 1s linear infinite; margin-bottom: 15px; }
+        @keyframes spin { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }
+        
         @keyframes blink { 0% { opacity: 0.5; } 50% { opacity: 1; } 100% { opacity: 0.5; } }
         .live { animation: blink 1s infinite; background: var(--green) !important; }
+        .spin-icon { animation: spin 1s linear infinite; }
     </style>
 </head>
 <body>
 
-<!-- SMART LOADER -->
-<div class="overlay" id="loader">
+<div class="loader-ov" id="loader">
     <div class="spinner"></div>
-    <div id="loadText" style="font-weight:700; font-size:14px; color:#555;">CONNECTING...</div>
+    <div id="loaderMsg" style="font-weight:700; color:var(--text-main); font-size:14px;">CONNECTING...</div>
 </div>
 
 <div class="modal" id="expModal">
@@ -278,8 +296,12 @@ HTML_TEMPLATE = """
 <div class="top-nav">
     <div style="display:flex; align-items:center; gap:15px;">
         <div style="font-weight:800; font-size:18px; color:var(--accent);">NIFTY 50</div>
-        <button class="btn" onclick="refreshDB()">REFRESH DB</button>
+        <button class="btn" onclick="refreshDB()" id="refreshBtn">
+            <svg id="refIcon" width="14" height="14" fill="none" stroke="currentColor" stroke-width="2" viewBox="0 0 24 24"><path d="M4 4v5h.582m15.356 2A8.001 8.001 0 004.582 9m0 0H9m11 11v-5h-.581m0 0a8.003 8.003 0 01-15.357-2m15.357 2H15"></path></svg>
+            REFRESH DB
+        </button>
     </div>
+    
     <div style="display:flex; gap:20px; align-items:center;">
         <div style="text-align:right;">
             <div style="font-size:10px; font-weight:700; color:#888;">SPOT</div>
@@ -288,7 +310,7 @@ HTML_TEMPLATE = """
         <button class="btn" onclick="openExpModal()">
             <span style="color:#888">EXP:</span> <span id="selExpTxt">SELECT</span>
         </button>
-        <button class="btn" onclick="location.href='/logout'" style="color:var(--red); border-color:var(--red)">LOGOUT</button>
+        <button class="btn" onclick="location.href='/logout'" style="border-color:var(--red); color:var(--red);">LOGOUT</button>
         <div id="statusDot" style="width:10px; height:10px; background:#ccc; border-radius:50%;"></div>
     </div>
 </div>
@@ -297,11 +319,12 @@ HTML_TEMPLATE = """
     <div class="chain-panel">
         <div class="chain-header">
             <div>CALL SELLERS (OI)</div>
-            <div>NET FLOW</div>
+            <div>NET FLOW (PUT S - CALL S)</div>
             <div>PUT SELLERS (OI)</div>
         </div>
         <div class="chain-body" id="chainBody"></div>
     </div>
+    
     <div class="fut-panel">
         <div style="padding:15px; font-weight:700; border-bottom:1px solid var(--border); background:#fff;">FUTURES</div>
         <div id="futBody"></div>
@@ -316,48 +339,53 @@ HTML_TEMPLATE = """
     let POLLER = null;
     let FUT_SYMS = [];
 
-    // === SMART STARTUP ===
-    window.onload = () => waitForDB();
+    // === STARTUP SEQUENCE ===
+    window.onload = () => { checkStatus(); };
 
-    async function waitForDB() {
-        const txt = document.getElementById('loadText');
-        
-        while(true) {
-            try {
-                // Check if Server is ready
-                let res = await fetch('/api/status');
-                let status = await res.json();
-                
-                if(status.status === 'ready') {
-                    txt.innerText = "LOADING DATA...";
-                    // Get Data
-                    let dbRes = await fetch('/api/db');
-                    DB = await dbRes.json();
-                    break; 
-                } else {
-                    txt.innerText = "SERVER WARMING UP (PLEASE WAIT)...";
-                }
-            } catch(e) {
-                txt.innerText = "CONNECTION ERROR...";
+    async function checkStatus() {
+        const msg = document.getElementById('loaderMsg');
+        try {
+            const res = await fetch('/api/status');
+            const status = await res.json();
+            
+            if(status.ready) {
+                msg.innerText = "LOADING DATA...";
+                loadDB();
+            } else {
+                msg.innerText = status.message.toUpperCase();
+                // Check again in 2 seconds
+                setTimeout(checkStatus, 2000);
             }
-            // Wait 1 sec before checking again
-            await new Promise(r => setTimeout(r, 1000));
+        } catch(e) {
+            msg.innerText = "CONNECTION LOST. RETRYING...";
+            setTimeout(checkStatus, 2000);
+        }
+    }
+
+    async function loadDB() {
+        try {
+            const res = await fetch('/api/init');
+            DB = await res.json();
+            if(!Array.isArray(DB) || DB.length === 0) {
+                 alert("DB Load Error. Retrying...");
+                 refreshDB(); // Try forcing
+                 return;
+            }
+            document.getElementById('loader').style.display = 'none';
+            initApp();
+        } catch(e) {
+            console.error(e);
         }
-        
-        document.getElementById('loader').style.opacity = '0';
-        setTimeout(() => document.getElementById('loader').style.display='none', 500);
-        initApp();
     }
 
     async function refreshDB() {
-        if(!confirm("Force Refresh Database? This takes 5-10 seconds.")) return;
-        document.getElementById('loader').style.display = 'flex';
-        document.getElementById('loader').style.opacity = '1';
-        document.getElementById('loadText').innerText = "UPDATING DATABASE...";
+        if(!confirm("Force download fresh data from NSE? This takes 10-20s.")) return;
+        const icon = document.getElementById('refIcon');
+        icon.classList.add('spin-icon');
         
         await fetch('/api/refresh');
-        // Loop back to wait function
-        waitForDB();
+        document.getElementById('loader').style.display = 'flex';
+        checkStatus();
     }
 
     function initApp() {
@@ -432,8 +460,10 @@ HTML_TEMPLATE = """
             const viewKs = viewRows.map(r => parseFloat(r.dataset.k));
             DB.forEach(i => { if(i.e === ACTIVE_EXP && viewKs.includes(i.k)) syms.push(i.s); });
         }
+
         try {
-            const res = await fetch(`/api/depth?symbols=${encodeURIComponent([...new Set(syms)].join(','))}&_=${Date.now()}`);
+            const ts = Date.now();
+            const res = await fetch(`/api/depth?symbols=${encodeURIComponent([...new Set(syms)].join(','))}&_=${ts}`);
             const json = await res.json();
             if(json.s === 'ok') {
                 const dot = document.getElementById('statusDot');
@@ -455,7 +485,8 @@ HTML_TEMPLATE = """
             if(!d) return '';
             const tot = (d.totalbuyqty + d.totalsellqty) || 1;
             const dt = new Date(obj.e * 1000).toLocaleDateString('en-GB', {day:'numeric', month:'short'});
-            return `<div class="fut-card">
+            return `
+            <div class="fut-card">
                 <div style="display:flex; justify-content:space-between; font-weight:700;">
                     <span>${dt} FUT</span> <span style="color:${d.ch>=0?'var(--green)':'var(--red)'}">${d.ltp}</span>
                 </div>
@@ -488,7 +519,6 @@ HTML_TEMPLATE = """
             const peDiv = document.getElementById(`pe-${k}`);
             if(ceDiv) ceDiv.innerHTML = `<span>S: <strong>${fmt(r.ce)}</strong></span>`;
             if(peDiv) peDiv.innerHTML = `<span>S: <strong>${fmt(r.pe)}</strong></span>`;
-            
             const bar = document.getElementById(`bar-${k}`);
             const val = document.getElementById(`val-${k}`);
             if(bar) {