use wake lock and setInterval

src/jensen.js

@@ -705,6 +705,7 @@ Jensen.prototype.getFile = async function (filename, length, ondata, onprogress)
     for (let i = 0; i < filename.length; i++) fname.push(filename.charCodeAt(i));
 
     let wakeLock = null;
+    let timer = null;
     async function visibilitychange() {
         let audio = document.getElementById('test_audio');
         if (!audio) {
@@ -720,6 +721,17 @@ Jensen.prototype.getFile = async function (filename, length, ondata, onprogress)
         if (document.visibilityState === 'hidden') {
             console.log('Page is hidden');
             audio.play();
+            timer = setInterval(() => {
+                console.log("Keeping the page alive...");
+            }, 1000)
+        } else {
+            audio.pause();
+            console.log('Page is visible');
+            wakeLock && wakeLock.release();
+            timer && clearInterval(timer)
+        }
+    }
+
     if ('wakeLock' in navigator) {
         try {
             wakeLock = await navigator.wakeLock.request('screen');
@@ -728,17 +740,12 @@ Jensen.prototype.getFile = async function (filename, length, ondata, onprogress)
             console.error('Failed to acquire wake lock:', err);
         }
     }
-        } else {
-            audio.pause();
-            console.log('Page is visible');
-            wakeLock && wakeLock.release();
-        }
-    }
 
     function removeAudio() {
         const audio = document.getElementById('test_audio');
         audio && audio.pause() && audio.remove();
         wakeLock && wakeLock.release();
+        timer && clearInterval(timer)
     }
 
     visibilitychange();