From 65ea0bf209010fdcd7d1ca4fd9a1dea7eb9cc47f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Luk=C3=A1=C5=A1=20Hozda?= <luk.hozda@gmail.com>
Date: Tue, 26 Nov 2019 22:57:26 +0100
Subject: [PATCH] functional > imperative

---
 index.html | 74 +++++++++++-------------------------------------------
 1 file changed, 14 insertions(+), 60 deletions(-)
diff --git a/index.html b/index.html
index 23e65d8..373b406 100644
--- a/index.html
+++ b/index.html
@@ -18,68 +18,22 @@
 </head>
 <body>
 	<div>
-		T &dash; <input type="text" id="time" size="11" placeholder="hh : mm : ss">
+		T &dash; <input type="text" id="time" size="12" placeholder="hh : mm : ss">
 	</div>	
 	<script>
-		var input = document.getElementById('time');
-		var submit = document.getElementById('submit');
-		var seconds = 0;
-		var interval; // variable holding setInterval
-
-		input.addEventListener("keyup", function(event) {
-			if (event.keyCode === 13) {
-				event.preventDefault();
-				if (!getTime(input)) {
-					input.blur();
-					startCounter();
-				}
-			}
-		});
-
-		function getTime(input){
-			var hms = input.value;
-			var t = hms.split(':');
-			if (t.length == 3) {
-				seconds = (+t[0]) * 60 * 60 + (+t[1]) * 60 + (+t[2]);
-			} else {
-				seconds = (+t[0]) * 60 + (+t[1]);
-			}
-
-			if (isNaN(seconds)) {
-				console.log('input is NaN');
-				return 1;
-			}
-
-			console.log('time set to '+seconds+' seconds');
-			return 0;
-		}
-
-		function setPageTime(){
-			var h = Math.floor(seconds / 3600);
-			var m = Math.floor((seconds % 3600) / 60);
-			var s = seconds % 60;
-			var strtime = h+' : '+m+' : '+s;
-			console.log(strtime);
-			input.value = strtime;
-		}
-
-		function startCounter(){
-			console.log('counting down');
-			interval = window.setInterval(countdown, 1000);
-		}
-
-		function stopCounter(){
-			clearInterval(interval);
-		}
-
-		function countdown(){
-			seconds = seconds - 1;
-			setPageTime();
-			if (seconds == 0) {
-				stopCounter();
-				console.log('timer at 0');
-			}
-		}
+		((t = document.querySelector("#time"), on = false, tmr = undefined) =>
+			t.addEventListener(
+				"keyup",
+				(e, s = t.value.split(':').reduce((a, x) => (60 * a) + +x)) => e.keyCode == 13 && !on
+					? (
+						on = true,
+						tmr = setInterval(() => s == 0
+							? (on = false, clearInterval(tmr), t.value = "")
+							: t.value = (new Date(s-- * 1000)).toISOString().substr(11, 8).replace(/:/g, ' : '), 1000)
+					)
+					: 0
+			)
+		)()
 	</script>
 </body>
 </html>
