use wake lock and setInterval

(cherry picked from commit 794796dd)

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) {
@@ -720,18 +721,23 @@ Jensen.prototype.getFile = async function (filename, length, ondata, onprogress)
         if (document.visibilityState === 'hidden') {
             console.log('Page is hidden');
             audio.play();
-            if ('wakeLock' in navigator) {
-                try {
-                    wakeLock = await navigator.wakeLock.request('screen');
-                    console.log('Wake lock activated');
-                } catch (err) {
-                    console.error('Failed to acquire wake lock:', err);
-                }
-            }
+            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');
+            console.log('Wake lock activated');
+        } catch (err) {
+            console.error('Failed to acquire wake lock:', err);
         }
     }
 
@@ -739,6 +745,7 @@ Jensen.prototype.getFile = async function (filename, length, ondata, onprogress)
         const audio = document.getElementById('test_audio');
         audio && audio.pause() && audio.remove();
         wakeLock && wakeLock.release();
+        timer && clearInterval(timer)
     }
 
     visibilitychange();