/
index.js
185 lines (148 loc) · 4.47 KB
/
index.js
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const ARIA_INVALID = "aria-invalid";
const oneWayOrReturnValues = {
oneWay: "oneWay",
returnFlight: "returnFlight",
};
const elems = {
departure: document.querySelector("#departure"),
oneWayOrReturn: document.querySelector("#oneWayOrReturn"),
return: document.querySelector("#return"),
book: document.querySelector("#book"),
};
// DOM setters ---------------------------------------------------------
function setError(elem) {
elem.setAttribute(ARIA_INVALID, true);
}
function clearError(elem) {
elem.setAttribute(ARIA_INVALID, false);
}
function disable(elem) {
elem.disabled = true;
}
function enable(elem) {
elem.disabled = false;
}
function showConfirmation() {
const message =
elems.oneWayOrReturn.value === oneWayOrReturnValues.oneWay
? `You have booked a one-way flight on ${elems.departure.value}.`
: `You have booked a return flight, departing on ${elems.departure.value} & returning on ${elems.return.value}.`;
window.alert(message);
}
// Validators ---------------------------------------------------------
function isOneWay() {
return elems.oneWayOrReturn.value === oneWayOrReturnValues.oneWay;
}
function isValidDate(date) {
return date instanceof Date && !isNaN(date);
}
function inputValueToDate(value) {
const split = value.split(".");
const [day, month, year] = split;
return new Date(`${year}-${month}-${day}`);
}
function isBadFormat(value) {
const split = value.split(".");
if (split.length !== 3) return true;
const date = inputValueToDate(value);
return !isValidDate(date);
}
function isEarlyReturn() {
const start = inputValueToDate(elems.departure.value).valueOf();
const end = inputValueToDate(elems.return.value).valueOf();
return end < start;
}
// State --------------------------------------------------------------
const states = {
oneWay: {
badDepartureFormat: "oneWay.BadDepartureFormat",
valid: "oneWay.valid",
},
returnFlight: {
badDepartureFormat: "returnFlight.badDepartureFormat",
badReturnFormat: "returnFlight.badReturnFormat",
badDepartureAndReturnFormat: "returnFlight.badDepartureAndReturnFormat",
earlyReturn: "returnFlight.earlyReturn",
valid: "returnFlight.valid",
},
};
function onStateChange(state) {
switch (state) {
case states.oneWay.badDepartureFormat:
disable(elems.book);
disable(elems.return);
setError(elems.departure);
clearError(elems.return);
break;
case states.oneWay.valid:
enable(elems.book);
disable(elems.return);
clearError(elems.departure);
clearError(elems.return);
break;
case states.returnFlight.badDepartureAndReturnFormat:
disable(elems.book);
enable(elems.return);
setError(elems.departure);
setError(elems.return);
break;
case states.returnFlight.badDepartureFormat:
disable(elems.book);
enable(elems.return);
setError(elems.departure);
clearError(elems.return);
break;
case states.returnFlight.badReturnFormat:
disable(elems.book);
enable(elems.return);
clearError(elems.departure);
setError(elems.return);
break;
case states.returnFlight.earlyReturn:
disable(elems.book);
enable(elems.return);
clearError(elems.departure);
setError(elems.return);
break;
case states.returnFlight.valid:
enable(elems.book);
enable(elems.return);
clearError(elems.departure);
clearError(elems.return);
break;
default:
throw Error(`Unknown state: ${state}`);
}
}
function calcState() {
const isBadDepart = isBadFormat(elems.departure.value);
const isBadReturn = isBadFormat(elems.return.value);
if (isOneWay()) {
return isBadDepart ? states.oneWay.badDepartureFormat : states.oneWay.valid;
}
if (isBadDepart && isBadReturn) {
return states.returnFlight.badDepartureAndReturnFormat;
}
if (isBadDepart) {
return states.returnFlight.badDepartureFormat;
}
if (isBadReturn) {
return states.returnFlight.badReturnFormat;
}
if (isEarlyReturn()) {
return states.returnFlight.earlyReturn;
}
return states.returnFlight.valid;
}
function onInputChange() {
const state = calcState();
onStateChange(state);
}
// DOM listeners ---------------------------------------------------------
elems.oneWayOrReturn.onchange = onInputChange;
elems.departure.oninput = onInputChange;
elems.return.oninput = onInputChange;
elems.book.onclick = function (event) {
event.preventDefault();
showConfirmation();
};