init Timer

js/main.js

@@ -0,0 +1,28 @@
+var htmlTimer = document.getElementById("timer");
+
+var timer = setInterval(timerLoop, 1000);
+const queryString = window.location.search;
+const urlParams = new URLSearchParams(queryString);
+let time = parseInt(urlParams.get('time'))
+
+
+function timerLoop() {
+    htmlTimer.innerHTML = convertSecMin(time);
+    time--;
+    if(time < 0) {
+        clearInterval(timer)
+        htmlTimer.style.color = "red";
+    }
+}
+
+function convertSecMin(value) {
+    let seconds = Math.floor(value % 60);
+    let minuts = Math.floor(value / 60);
+    return `${convertDigits(minuts)}:${convertDigits(seconds)}` 
+}
+
+function convertDigits(number) {
+    return number.toLocaleString('en-US', {
+        minimumIntegerDigits : 2,
+        useGrouping : false});
+}