fix: speed calculation

components/downloads/DownloadCard.tsx

@@ -14,6 +14,7 @@ import {
 import { toast } from "sonner-native";
 import { Text } from "@/components/common/Text";
 import { useDownload } from "@/providers/DownloadProvider";
+import { calculateSmoothedETA } from "@/providers/Downloads/hooks/useDownloadSpeedCalculator";
 import { JobStatus } from "@/providers/Downloads/types";
 import { storage } from "@/utils/mmkv";
 import { formatTimeString } from "@/utils/time";
@@ -62,16 +63,23 @@ export const DownloadCard = ({ process, ...props }: DownloadCardProps) => {
     }
   };
 
-  const eta = (p: JobStatus) => {
-    if (!p.speed || p.speed <= 0 || !p.estimatedTotalSizeBytes) return null;
+  const eta = useMemo(() => {
+    if (!process.estimatedTotalSizeBytes || !process.bytesDownloaded) {
+      return null;
+    }
 
-    const bytesRemaining = p.estimatedTotalSizeBytes - (p.bytesDownloaded || 0);
-    if (bytesRemaining <= 0) return null;
+    const secondsRemaining = calculateSmoothedETA(
+      process.id,
+      process.bytesDownloaded,
+      process.estimatedTotalSizeBytes,
+    );
 
-    const secondsRemaining = bytesRemaining / p.speed;
+    if (!secondsRemaining || secondsRemaining <= 0) {
+      return null;
+    }
 
     return formatTimeString(secondsRemaining, "s");
-  };
+  }, [process.id, process.bytesDownloaded, process.estimatedTotalSizeBytes]);
 
   const base64Image = useMemo(() => {
     return storage.getString(process.item.Id!);
@@ -161,9 +169,9 @@ export const DownloadCard = ({ process, ...props }: DownloadCardProps) => {
                   {bytesToMB(process.speed).toFixed(2)} MB/s
                 </Text>
               )}
-              {eta(process) && (
+              {eta && (
                 <Text className='text-xs'>
-                  {t("home.downloads.eta", { eta: eta(process) })}
+                  {t("home.downloads.eta", { eta: eta })}
                 </Text>
               )}
             </View>

modules/background-downloader/ios/BackgroundDownloaderModule.swift

@@ -19,6 +19,7 @@ class DownloadSessionDelegate: NSObject, URLSessionDownloadDelegate {
   init(module: BackgroundDownloaderModule) {
     self.module = module
     super.init()
+    print("[DownloadSessionDelegate] Delegate initialized with module: \(String(describing: module))")
   }
   
   func urlSession(
@@ -141,10 +142,73 @@ public class BackgroundDownloaderModule: Module {
       DispatchQueue.main.asyncAfter(deadline: .now() + 0.5) {
         session.getAllTasks { tasks in
           if let downloadTask = tasks.first(where: { $0.taskIdentifier == taskId }) {
-            print("[BackgroundDownloader] Task state after 0.5s: \(self.taskStateString(downloadTask.state))")
+            print("[BackgroundDownloader] === 0.5s CHECK ===")
+            print("[BackgroundDownloader] Task state: \(self.taskStateString(downloadTask.state))")
             if let response = downloadTask.response as? HTTPURLResponse {
               print("[BackgroundDownloader] Response status: \(response.statusCode)")
               print("[BackgroundDownloader] Expected content length: \(response.expectedContentLength)")
+            } else {
+              print("[BackgroundDownloader] No HTTP response yet after 0.5s")
+            }
+          } else {
+            print("[BackgroundDownloader] Task not found after 0.5s")
+          }
+        }
+      }
+      
+      // Additional diagnostics at 1s, 2s, and 3s
+      DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
+        session.getAllTasks { tasks in
+          if let downloadTask = tasks.first(where: { $0.taskIdentifier == taskId }) {
+            print("[BackgroundDownloader] === 1s CHECK ===")
+            print("[BackgroundDownloader] Task state: \(self.taskStateString(downloadTask.state))")
+            print("[BackgroundDownloader] Task error: \(String(describing: downloadTask.error))")
+            print("[BackgroundDownloader] Current request URL: \(downloadTask.currentRequest?.url?.absoluteString ?? "nil")")
+            print("[BackgroundDownloader] Original request URL: \(downloadTask.originalRequest?.url?.absoluteString ?? "nil")")
+            
+            if let response = downloadTask.response as? HTTPURLResponse {
+              print("[BackgroundDownloader] HTTP Status: \(response.statusCode)")
+              print("[BackgroundDownloader] Expected content length: \(response.expectedContentLength)")
+              print("[BackgroundDownloader] All headers: \(response.allHeaderFields)")
+            } else {
+              print("[BackgroundDownloader] ⚠️ STILL NO HTTP RESPONSE after 1s")
+            }
+            
+            let countOfBytesReceived = downloadTask.countOfBytesReceived
+            if countOfBytesReceived > 0 {
+              print("[BackgroundDownloader] Bytes received: \(countOfBytesReceived)")
+            } else {
+              print("[BackgroundDownloader] ⚠️ NO BYTES RECEIVED YET")
+            }
+          } else {
+            print("[BackgroundDownloader] ⚠️ Task disappeared after 1s")
+          }
+        }
+      }
+      
+      DispatchQueue.main.asyncAfter(deadline: .now() + 2.0) {
+        session.getAllTasks { tasks in
+          if let downloadTask = tasks.first(where: { $0.taskIdentifier == taskId }) {
+            print("[BackgroundDownloader] === 2s CHECK ===")
+            print("[BackgroundDownloader] Task state: \(self.taskStateString(downloadTask.state))")
+            let countOfBytesReceived = downloadTask.countOfBytesReceived
+            print("[BackgroundDownloader] Bytes received: \(countOfBytesReceived)")
+            if downloadTask.error != nil {
+              print("[BackgroundDownloader] ⚠️ Task has error: \(String(describing: downloadTask.error))")
+            }
+          }
+        }
+      }
+      
+      DispatchQueue.main.asyncAfter(deadline: .now() + 3.0) {
+        session.getAllTasks { tasks in
+          if let downloadTask = tasks.first(where: { $0.taskIdentifier == taskId }) {
+            print("[BackgroundDownloader] === 3s CHECK ===")
+            print("[BackgroundDownloader] Task state: \(self.taskStateString(downloadTask.state))")
+            let countOfBytesReceived = downloadTask.countOfBytesReceived
+            print("[BackgroundDownloader] Bytes received: \(countOfBytesReceived)")
+            if downloadTask.error != nil {
+              print("[BackgroundDownloader] ⚠️ Task has error: \(String(describing: downloadTask.error))")
             }
           }
         }
@@ -173,17 +237,20 @@ public class BackgroundDownloaderModule: Module {
     
     AsyncFunction("getActiveDownloads") { () -> [[String: Any]] in
       return try await withCheckedThrowingContinuation { continuation in
+        let downloadTasks = self.downloadTasks
+        let taskStateString = self.taskStateString
+        
         self.session?.getAllTasks { tasks in
           let activeDownloads = tasks.compactMap { task -> [String: Any]? in
             guard task is URLSessionDownloadTask,
-                  let info = self.downloadTasks[task.taskIdentifier] else {
+                  let info = downloadTasks[task.taskIdentifier] else {
               return nil
             }
             
             return [
               "taskId": task.taskIdentifier,
               "url": info.url,
-              "state": self.taskStateString(task.state)
+              "state": taskStateString(task.state)
             ]
           }
           continuation.resume(returning: activeDownloads)
@@ -210,6 +277,15 @@ public class BackgroundDownloaderModule: Module {
     )
     
     print("[BackgroundDownloader] URLSession initialized with delegate: \(String(describing: self.sessionDelegate))")
+    print("[BackgroundDownloader] Session identifier: \(config.identifier ?? "nil")")
+    print("[BackgroundDownloader] Delegate queue: nil (uses default)")
+    
+    // Verify delegate is connected
+    if let session = self.session, session.delegate != nil {
+      print("[BackgroundDownloader] ✅ Delegate successfully attached to session")
+    } else {
+      print("[BackgroundDownloader] ⚠️ DELEGATE NOT ATTACHED!")
+    }
   }
   
   private func taskStateString(_ state: URLSessionTask.State) -> String {

providers/Downloads/hooks/useDownloadSpeedCalculator.ts

@@ -4,11 +4,13 @@ interface SpeedDataPoint {
 }
 
 const WINDOW_DURATION = 60000; // 1 minute in ms
-const MIN_DATA_POINTS = 3; // Need at least 3 points for accurate speed
+const MIN_DATA_POINTS = 5; // Need at least 5 points for accurate speed
 const MAX_REASONABLE_SPEED = 1024 * 1024 * 1024; // 1 GB/s sanity check
+const EMA_ALPHA = 0.2; // Smoothing factor for EMA (lower = smoother, 0-1 range)
 
 // Private state
 const dataPoints = new Map<string, SpeedDataPoint[]>();
+const emaSpeed = new Map<string, number>(); // Store EMA speed for each process
 
 function isValidBytes(bytes: number): boolean {
   return typeof bytes === "number" && Number.isFinite(bytes) && bytes >= 0;
@@ -161,7 +163,8 @@ export function calculateWeightedSpeed(processId: string): number | undefined {
     }
 
     // More recent points get exponentially higher weight
-    const weight = 2 ** i;
+    // Using 1.3 instead of 2 for gentler weighting (less sensitive to recent changes)
+    const weight = 1.3 ** i;
     totalWeightedSpeed += speed * weight;
     totalWeight += weight;
   }
@@ -180,12 +183,74 @@ export function calculateWeightedSpeed(processId: string): number | undefined {
   return weightedSpeed;
 }
 
+// Calculate ETA in seconds
+export function calculateETA(
+  processId: string,
+  bytesDownloaded: number,
+  totalBytes: number,
+): number | undefined {
+  const speed = calculateWeightedSpeed(processId);
+
+  if (!speed || speed <= 0 || !totalBytes || totalBytes <= 0) {
+    return undefined;
+  }
+
+  const bytesRemaining = totalBytes - bytesDownloaded;
+  if (bytesRemaining <= 0) {
+    return 0;
+  }
+
+  const secondsRemaining = bytesRemaining / speed;
+
+  // Sanity check
+  if (!Number.isFinite(secondsRemaining) || secondsRemaining < 0) {
+    return undefined;
+  }
+
+  return secondsRemaining;
+}
+
+// Calculate smoothed ETA using Exponential Moving Average (EMA)
+// This provides much smoother ETA estimates, reducing jumpy time estimates
+const emaETA = new Map<string, number>();
+
+export function calculateSmoothedETA(
+  processId: string,
+  bytesDownloaded: number,
+  totalBytes: number,
+): number | undefined {
+  const currentETA = calculateETA(processId, bytesDownloaded, totalBytes);
+
+  if (currentETA === undefined) {
+    return undefined;
+  }
+
+  const previousEma = emaETA.get(processId);
+
+  if (previousEma === undefined) {
+    // First calculation, initialize with current ETA
+    emaETA.set(processId, currentETA);
+    return currentETA;
+  }
+
+  // EMA formula: EMA(t) = α * current + (1 - α) * EMA(t-1)
+  // Lower alpha = smoother but slower to respond
+  const smoothed = EMA_ALPHA * currentETA + (1 - EMA_ALPHA) * previousEma;
+
+  emaETA.set(processId, smoothed);
+  return smoothed;
+}
+
 export function clearSpeedData(processId: string): void {
   dataPoints.delete(processId);
+  emaSpeed.delete(processId);
+  emaETA.delete(processId);
 }
 
 export function resetAllSpeedData(): void {
   dataPoints.clear();
+  emaSpeed.clear();
+  emaETA.clear();
 }
 
 // Debug function to inspect current state