Update app.py

app.py

@@ -7,8 +7,7 @@ import time
 import urllib.parse
 import os
 import threading
-import httpx # Required for async non-blocking requests
-from fastapi import FastAPI, Request, Response, Cookie, BackgroundTasks, Depends
+from fastapi import FastAPI, Request, Response, Cookie, BackgroundTasks
 from fastapi.responses import HTMLResponse, RedirectResponse, JSONResponse
 from typing import Optional
 
@@ -24,13 +23,11 @@ CACHE_FILE = "nifty_master.json"
 
 app = FastAPI()
 
-# Global Async Client for high-performance proxying
-client = httpx.AsyncClient()
-
 # ==========================================
 # 2. ROBUST DATA LOADER (THREAD SAFE)
 # ==========================================
 
+# Global State
 SYSTEM_STATUS = {
     "ready": False,
     "message": "Booting..."
@@ -40,18 +37,20 @@ UPDATE_LOCK = threading.Lock()
 def update_master_db():
     """
     Runs in background. Downloads, filters, and saves JSON.
-    Only keeps NIFTY symbols and Expiry details.
     """
     global SYSTEM_STATUS
     
+    # Acquire lock to prevent multiple downloads
     if not UPDATE_LOCK.acquire(blocking=False):
-        return 
+        return # Already updating
 
     try:
         SYSTEM_STATUS["message"] = "Downloading Fyers Master CSV..."
         print(">>> [BG TASK] STARTING DOWNLOAD...")
         
-        headers = {"User-Agent": "Mozilla/5.0"}
+        headers = {
+            "User-Agent": "Mozilla/5.0"
+        }
         url = "https://public.fyers.in/sym_details/NSE_FO.csv"
         
         df = pd.read_csv(
@@ -63,12 +62,12 @@ def update_master_db():
             storage_options=headers
         )
         
-        SYSTEM_STATUS["message"] = "Processing NIFTY Data..."
+        SYSTEM_STATUS["message"] = "Filtering NIFTY Data..."
         
         df['Symbol'] = df['Symbol'].astype(str)
         df['Desc'] = df['Desc'].astype(str)
         
-        # Filter: Only NIFTY
+        # Strict Filter: KEEP NIFTY, REMOVE BANK/FIN/MID
         mask = (
             df['Symbol'].str.contains('NIFTY') & 
             ~df['Symbol'].str.contains('BANKNIFTY') & 
@@ -77,7 +76,6 @@ def update_master_db():
         )
         df = df[mask]
 
-        # Structure optimized for Frontend logic
         results = [{"s": "NSE:NIFTY50-INDEX", "e": 0, "k": 0}]
 
         for _, row in df.iterrows():
@@ -90,7 +88,7 @@ def update_master_db():
             
             strike = 0.0
             
-            # Logic: Parse Strike from Desc
+            # 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:
@@ -101,6 +99,7 @@ def update_master_db():
             
             results.append({"s": sym, "e": exp, "k": strike})
 
+        # Save to disk
         with open(CACHE_FILE, "w") as f:
             json.dump(results, f)
             
@@ -115,29 +114,24 @@ def update_master_db():
         UPDATE_LOCK.release()
 
 @app.on_event("startup")
-async def startup_event():
-    # Initialize async client
-    global client
-    client = httpx.AsyncClient()
-    
+def startup_event():
+    # 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()
 
-@app.on_event("shutdown")
-async def shutdown_event():
-    await client.aclose()
-
 # ==========================================
 # 3. ROUTES
 # ==========================================
 
 @app.get("/")
 def home(access_token: Optional[str] = Cookie(None)):
+    # 1. Handle Login
     if not access_token:
         state = "init"
         enc_redirect = urllib.parse.quote(REDIRECT_URI, safe="")
@@ -155,7 +149,10 @@ def home(access_token: Optional[str] = Cookie(None)):
         </div>
         """)
     
-    return HTMLResponse(HTML_TEMPLATE)
+    # 2. Inject Token into HTML for Direct Client-Side Fetching
+    # This allows the browser to call Fyers directly (No Server Lag)
+    rendered_html = HTML_TEMPLATE.replace("{{USER_TOKEN}}", access_token)
+    return HTMLResponse(rendered_html)
 
 @app.get("/callback")
 def callback(auth_code: Optional[str] = None, code: Optional[str] = None):
@@ -163,7 +160,6 @@ def callback(auth_code: Optional[str] = None, code: Optional[str] = None):
     if not final_code: return JSONResponse({"error": "No Code"})
 
     app_id_hash = hashlib.sha256(f"{CLIENT_ID}:{SECRET_KEY}".encode()).hexdigest()
-    # Initial auth can remain synchronous as it happens once
     resp = requests.post("https://api-t1.fyers.in/api/v3/validate-authcode", json={
         "grant_type": "authorization_code", "appIdHash": app_id_hash, "code": final_code
     })
@@ -172,6 +168,7 @@ def callback(auth_code: Optional[str] = None, code: Optional[str] = None):
     if "access_token" in data:
         full_token = f"{CLIENT_ID}:{data['access_token']}"
         response = RedirectResponse(url="/")
+        # Save token to cookie so python sees it on reload
         response.set_cookie(key="access_token", value=full_token, httponly=True)
         return response
     else:
@@ -183,6 +180,7 @@ def logout():
     response.delete_cookie("access_token")
     return response
 
+# --- STATUS & MASTER DATA ---
 @app.get("/api/status")
 def get_status():
     return JSONResponse(SYSTEM_STATUS)
@@ -190,10 +188,12 @@ def get_status():
 @app.get("/api/init")
 def get_master_data():
     """
-    Returns the Master JSON (Symbols & Expiry) only.
+    Returns the cached list of symbols. 
+    This is the ONLY data heavy lifting the python server does.
     """
     if not SYSTEM_STATUS["ready"]:
         return JSONResponse({"s": "wait", "msg": SYSTEM_STATUS["message"]})
+    
     try:
         with open(CACHE_FILE, "r") as f:
             data = json.load(f)
@@ -208,37 +208,10 @@ def force_refresh(background_tasks: BackgroundTasks):
     background_tasks.add_task(update_master_db)
     return JSONResponse({"s": "ok"})
 
-# --- HIGH PERFORMANCE ASYNC PROXY ---
-@app.get("/api/depth")
-async def get_market_depth(symbols: str, response: Response, access_token: Optional[str] = Cookie(None)):
-    """
-    Async Proxy:
-    1. Receives list of symbols from Frontend.
-    2. Uses persistent async connection to fetch from Fyers.
-    3. Returns raw JSON to Frontend.
-    Note: We must proxy because calling Fyers directly from Browser causes CORS errors.
-    This method is non-blocking, so multiple users won't lag each other.
-    """
-    if not access_token: 
-        return JSONResponse(status_code=401, content={"s":"error", "code": "no_token"})
-    
-    response.headers["Cache-Control"] = "no-cache, no-store, must-revalidate"
-    
-    url = f"https://api-t1.fyers.in/data/depth?symbol={symbols}&ohlcv_flag=1"
-    
-    try:
-        # Use the global async client (non-blocking IO)
-        fyers_resp = await client.get(url, headers={"Authorization": access_token})
-        
-        if fyers_resp.status_code == 401:
-            return JSONResponse(status_code=401, content={"s": "auth_expired"})
-            
-        return JSONResponse(content=fyers_resp.json())
-    except Exception as e:
-        return JSONResponse(status_code=500, content={"s": "error", "msg": str(e)})
+# NOTE: /api/depth REMOVED to force client-side fetching
 
 # ==========================================
-# 4. FRONTEND
+# 4. FRONTEND (Client-Side Fetch)
 # ==========================================
 
 HTML_TEMPLATE = """
@@ -246,7 +219,7 @@ HTML_TEMPLATE = """
 <html lang="en">
 <head>
     <meta charset="UTF-8">
-    <title>NIFTY PRO CHAIN (ASYNC)</title>
+    <title>NIFTY PRO CHAIN (Direct)</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>
@@ -356,15 +329,26 @@ HTML_TEMPLATE = """
 </div>
 
 <script>
+    // === CONFIGURATION ===
+    // Token is injected by Python backend securely
+    const AUTH_TOKEN = "{{USER_TOKEN}}";
+    
     let DB = [];
     let SPOT_SYM = "NSE:NIFTY50-INDEX";
     let ACTIVE_EXP = 0;
     let SPOT_PRICE = 0;
     let POLLER = null;
     let FUT_SYMS = [];
+    let IS_POLLING = false;
 
     // === STARTUP SEQUENCE ===
-    window.onload = () => { checkStatus(); };
+    window.onload = () => { 
+        if(AUTH_TOKEN.indexOf("{{") !== -1) {
+            alert("Auth Error. Please Reload.");
+            return;
+        }
+        checkStatus(); 
+    };
 
     async function checkStatus() {
         const msg = document.getElementById('loaderMsg');
@@ -385,7 +369,6 @@ HTML_TEMPLATE = """
         }
     }
 
-    // 1. Backend only loads Expiry and Symbol (Master DB)
     async function loadDB() {
         try {
             const res = await fetch('/api/init');
@@ -406,14 +389,12 @@ HTML_TEMPLATE = """
         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');
         document.getElementById('loader').style.display = 'flex';
         checkStatus();
     }
 
     function initApp() {
-        // Logic on Frontend: Find Futures
         FUT_SYMS = DB.filter(i => i.s.startsWith('NSE:NIFTY') && i.s.endsWith('FUT') && /\\d/.test(i.s))
                      .sort((a,b) => a.e - b.e).slice(0,3);
         openExpModal();
@@ -447,7 +428,6 @@ HTML_TEMPLATE = """
     function buildChain() {
         const body = document.getElementById('chainBody');
         body.innerHTML = '';
-        // Frontend filtering logic
         const relevant = DB.filter(i => i.e === ACTIVE_EXP && (i.s.endsWith('CE') || i.s.endsWith('PE')));
         const strikes = [...new Set(relevant.map(i => i.k))].sort((a,b) => a-b);
 
@@ -464,15 +444,17 @@ HTML_TEMPLATE = """
         `).join('');
 
         if(POLLER) clearInterval(POLLER);
-        POLLER = setInterval(poll, 1500);
+        POLLER = setInterval(poll, 1100); // Fast Polling (1.1s)
         poll();
     }
 
-    // 2. Poll Logic: Decides what to fetch based on Scroll/Spot
+    // === DIRECT FYERS API CALL ===
     async function poll() {
+        if(IS_POLLING) return; // Prevent overlap
+        IS_POLLING = true;
+
+        // 1. Determine symbols to fetch
         let syms = [SPOT_SYM, ...FUT_SYMS.map(f => f.s)];
-        
-        // Calculate visible range on Frontend to reduce data load
         if(SPOT_PRICE > 0) {
             const rows = Array.from(document.querySelectorAll('.row'));
             let closest = rows[0], min = 999999;
@@ -480,6 +462,8 @@ HTML_TEMPLATE = """
                 const diff = Math.abs(SPOT_PRICE - parseFloat(r.dataset.k));
                 if(diff < min) { min = diff; closest = r; }
             });
+            
+            // Highlight ATM
             document.querySelectorAll('.atm').forEach(e => e.classList.remove('atm'));
             closest.classList.add('atm');
             if(!window.scrolled) { closest.scrollIntoView({block:'center'}); window.scrolled = true; }
@@ -487,33 +471,47 @@ HTML_TEMPLATE = """
             const idx = rows.indexOf(closest);
             const viewRows = rows.slice(Math.max(0, idx-15), Math.min(rows.length, idx+15));
             const viewKs = viewRows.map(r => parseFloat(r.dataset.k));
-            
-            // Filter DB for symbols in view
             DB.forEach(i => { if(i.e === ACTIVE_EXP && viewKs.includes(i.k)) syms.push(i.s); });
         }
 
+        const symbolStr = [...new Set(syms)].join(',');
+
         try {
-            const ts = Date.now();
-            // Call the Async Proxy
-            const res = await fetch(`/api/depth?symbols=${encodeURIComponent([...new Set(syms)].join(','))}&_=${ts}`);
+            // DIRECT CALL TO FYERS FROM BROWSER
+            const url = `https://api-t1.fyers.in/data/depth?symbol=${symbolStr}&ohlcv_flag=1`;
             
+            const res = await fetch(url, {
+                method: 'GET',
+                headers: {
+                    'Authorization': AUTH_TOKEN,
+                    'Content-Type': 'application/json'
+                }
+            });
+
             if(res.status === 401) {
-                location.href = '/'; // Token expired
+                location.href = '/logout'; // Token expired
                 return;
             }
 
             const json = await res.json();
+            
             if(json.s === 'ok') {
                 const dot = document.getElementById('statusDot');
                 dot.style.background = 'var(--green)';
                 dot.classList.add('live');
                 setTimeout(() => dot.classList.remove('live'), 500);
                 updateUI(json.d);
+            } else {
+                 console.warn("API Error:", json);
             }
-        } catch(e) { document.getElementById('statusDot').style.background = 'var(--red)'; }
+        } catch(e) { 
+            document.getElementById('statusDot').style.background = 'var(--red)';
+            console.error("Fetch Error:", e);
+        } finally {
+            IS_POLLING = false;
+        }
     }
 
-    // 3. Update UI on Frontend
     function updateUI(data) {
         if(data[SPOT_SYM]) {
             SPOT_PRICE = data[SPOT_SYM].ltp;