diff --git a/Sprint-3/alarmclock/alarmclock.js b/Sprint-3/alarmclock/alarmclock.js
index 6ca81cd3b..c7974c25a 100644
--- a/Sprint-3/alarmclock/alarmclock.js
+++ b/Sprint-3/alarmclock/alarmclock.js
@@ -1,4 +1,114 @@
-function setAlarm() {}
+// Given an input area of Time counter and 2 buttons: 'Set Alarm' and 'Stop Alarm'.
+// When user clicks the `Set Alarm` button the counter at the
+// top of the screen should change to the entered number in the `input` field.
+// For example,
+// if the `input` field says `10` then the title should say `Time Remaining: 00:10`.
+// Every one second the title should count down by one.
+
+// When the `Time Remaining` reaches `00:00` the alarm should play a sound. You can
+// make the sound happen by using `playAlarm()`.
+// You can stop the alarm sound by pressing the `Stop Alarm` button.
+
+const alarmInputArea = document.querySelector("#alarmSet"); // get access to InputArea
+console.log(alarmInputArea, "<---- InputArea");
+
+const setAlarmButton = document.querySelector("#set");
+console.log(setAlarmButton, "<---- Alarm Button");
+
+const setStopButton = document.querySelector("#stop");
+console.log(setStopButton, "< ---- Stop Button");
+
+const timeRemainInfo = document.querySelector("#timeRemaining");
+console.log(timeRemainInfo, "<------Remain Time");
+
+const backgroundColor = document.querySelector("html");
+console.log(backgroundColor, "<------Background Color");
+
+let intervalId; // declare variable
+let inputInfo = 0; // declare 'inputInfo' as an 'intervalId' global
+
+function timeFormat(time) {
+ // revert number into min and sec format function
+ const mins = String(Math.floor(time / 60)).padStart(2, "0");
+ const seconds = String(time % 60).padStart(2, "0");
+ timeRemainInfo.textContent = `Time Remaining: ${mins}:${seconds}`;
+}
+
+function setAlarm() {
+ inputInfo = Number(alarmInputArea.value); // convert input into number
+ if (intervalId || flashIntervalId) {
+ // edge case if during already set
+ // timer user input new one value
+ console.log("Timer already started!");
+ window.alert("Timer already started!");
+ clearInterval(intervalId);
+ clearInterval(flashIntervalId);
+ intervalId = null; // we should assign null to variables intervalId and
+ flashIntervalId = null; // flashIntervalId because resetting interval doesn't
+ alarmInputArea.value = ""; // assign new values to variables it just stop ticking
+ // timer
+ backgroundColor.style.backgroundColor = "";
+ timeFormat(0);
+ return;
+ }
+
+ if (inputInfo < 1 || isNaN(inputInfo)) {
+ // to sift invalid input
+ console.log("You need to input a value in seconds!");
+ window.alert("You need to input a value in seconds!");
+ return;
+ }
+ alarmInputArea.value = ""; // clean input area when data assigned to 'inputInfo'
+ timeFormat(inputInfo); // set format input to min and sec
+
+ intervalId = setInterval(function () {
+ //function to set interval for
+ inputInfo--; // countdown the input by 1 sec by iterat.
+ if (inputInfo === 0) {
+ // if input equal 0, set alarm signal and flashing
+ clearInterval(intervalId);
+ timeFormat(0);
+ window.playAlarm();
+ changeBackgroundColorFlashing();
+ } else {
+ // if input not equal 0, just continue count down
+ timeFormat(inputInfo);
+ }
+ }, 1000);
+}
+
+let flashColor = ["yellow", "pink", "lightgrey", "green"]; // array for flashing
+let flashIntervalId; // declaring globally variable
+let colorIndex = 0;
+
+setStopButton.addEventListener("click", function stopFlashing() {
+ console.log("click event is firing...");
+ clearInterval(flashIntervalId);
+ clearInterval(intervalId); // cleaning any previous possible intervals
+ intervalId = null;
+ flashIntervalId = null;
+ inputInfo = 0;
+ alarmInputArea.value = "";
+ backgroundColor.style.backgroundColor = "";
+ // cleaning background to default
+ timeFormat(0);
+ // option after clicking stop button
+ window.pauseAlarm();
+});
+
+function changeBackgroundColorFlashing() {
+ //function flashing colors
+ if (flashIntervalId) clearInterval(flashIntervalId);
+ flashIntervalId = setInterval(function () {
+ // every 1 sec
+ backgroundColor.style.backgroundColor = flashColor[colorIndex];
+ colorIndex = (colorIndex + 1) % flashColor.length; // loop over flashColor array
+ }, 1000);
+ //stopFlashing(); //setTimeout(() => clearInterval(flashIntervalId), 1000);
+}
+
+window.playAlarm = playAlarm;
+window.pauseAlarm = pauseAlarm;
// DO NOT EDIT BELOW HERE
diff --git a/Sprint-3/alarmclock/index.html b/Sprint-3/alarmclock/index.html
index 48e2e80d9..d353f6f51 100644
--- a/Sprint-3/alarmclock/index.html
+++ b/Sprint-3/alarmclock/index.html
@@ -4,7 +4,8 @@
- Title here
+
+ Alarm clock app