var start = document.getElementById('start');
var reset = document.getElementById('reset');
var pause = document.getElementById('pause');
var h = document.getElementById("hour");
var m = document.getElementById("minute");
var s = document.getElementById("sec");
//store a reference to the startTimer variable
var startTimer = null;
start.disabled = true;
[h, m, s].forEach(input => {
input.addEventListener('input', () => {
if (h.value > 0 || m.value > 0 || s.value > 0) {
start.disabled = false;
} else {
start.disabled = true;
}
});
});
start.addEventListener('click', function(){
//initialize the variable
function startInterval(){
startTimer = setInterval(function() {
timer();
}, 1000);
}
startInterval();
start.style.display = "none";
pause.style.display = "inline-block";
reset.style.display = "inline-block";
})
pause.addEventListener('click', function(){
stopInterval();
pause.style.display = "none";
start.style.display = "inline-block";
});
reset.addEventListener('click', function(){
h.value = 0;
m.value = 0;
s.value = 0;
//stop the timer after pressing "reset"
stopInterval();
start.disabled = true;
start.style.display = "inline-block";
pause.style.display = "none";
reset.style.display = "none";
})
function timer(){
if(h.value == 0 && m.value == 0 && s.value == 0){
h.value = 0;
m.value = 0;
s.value = 0;
start.disabled = true;
} else if(s.value != 0){
s.value--;
} else if(m.value != 0 && s.value == 0){
s.value = 59;
m.value--;
} else if(h.value != 0 && m.value == 0){
m.value = 60;
h.value--;
}
if (h.value == 0 && m.value == 0 && s.value == 0) {
start.disabled = true;
}
return;
}
//stop the function after pressing the reset button,
//so the time wont go down when selecting a new time after pressing reset
function stopInterval() {
clearInterval(startTimer);
}