Change admin announcement edition interface to use datetime-local (#18321)

* Change admin announcement edition interface to use datetime-local

* Dynamically set announcement stop date as required if start date is set, set minimum date for stop date

* Change `all_day` to not be bound to presence of time-range

* Add pattern and placeholder as minimal fallback for browsers not supporting datetime-local

* Display datetime-local inputs as local time

Co-authored-by: Eugen Rochko <eugen@zeonfederated.com>

app/javascript/packs/admin.js

@@ -2,6 +2,24 @@ import './public-path';
 import { delegate } from '@rails/ujs';
 import ready from '../mastodon/ready';
 
+const setAnnouncementEndsAttributes = (target) => {
+  const valid = target?.value && target?.validity?.valid;
+  const element = document.querySelector('input[type="datetime-local"]#announcement_ends_at');
+  if (valid) {
+    element.classList.remove('optional');
+    element.required = true;
+    element.min = target.value;
+  } else {
+    element.classList.add('optional');
+    element.removeAttribute('required');
+    element.removeAttribute('min');
+  }
+};
+
+delegate(document, 'input[type="datetime-local"]#announcement_starts_at', 'change', ({ target }) => {
+  setAnnouncementEndsAttributes(target);
+});
+
 const batchCheckboxClassName = '.batch-checkbox input[type="checkbox"]';
 
 const showSelectAll = () => {
@@ -141,6 +159,20 @@ const onChangeRegistrationMode = (target) => {
   });
 };
 
+const convertUTCDateTimeToLocal = (value) => {
+  const date = new Date(value + 'Z');
+  const twoChars = (x) => (x.toString().padStart(2, '0'));
+  return `${date.getFullYear()}-${twoChars(date.getMonth()+1)}-${twoChars(date.getDate())}T${twoChars(date.getHours())}:${twoChars(date.getMinutes())}`;
+};
+
+const convertLocalDatetimeToUTC = (value) => {
+  const re = /^([0-9]{4,})-([0-9]{2})-([0-9]{2})T([0-9]{2}):([0-9]{2})/;
+  const match = re.exec(value);
+  const date = new Date(match[1], match[2] - 1, match[3], match[4], match[5]);
+  const fullISO8601 = date.toISOString();
+  return fullISO8601.slice(0, fullISO8601.indexOf('T') + 6);
+};
+
 delegate(document, '#form_admin_settings_registrations_mode', 'change', ({ target }) => onChangeRegistrationMode(target));
 
 ready(() => {
@@ -163,6 +195,28 @@ ready(() => {
     }
   });
 
+  [].forEach.call(document.querySelectorAll('input[type="datetime-local"]'), element => {
+    if (element.value) {
+      element.value = convertUTCDateTimeToLocal(element.value);
+    }
+    if (element.placeholder) {
+      element.placeholder = convertUTCDateTimeToLocal(element.placeholder);
+    }
+  });
+
+  delegate(document, 'form', 'submit', ({ target }) => {
+    [].forEach.call(target.querySelectorAll('input[type="datetime-local"]'), element => {
+      if (element.value && element.validity.valid) {
+        element.value = convertLocalDatetimeToUTC(element.value);
+      }
+    });
+  });
+
+  const announcementStartsAt = document.querySelector('input[type="datetime-local"]#announcement_starts_at');
+  if (announcementStartsAt) {
+    setAnnouncementEndsAttributes(announcementStartsAt);
+  }
+
   const React    = require('react');
   const ReactDOM = require('react-dom');
 

app/javascript/styles/mastodon/forms.scss

@@ -405,6 +405,7 @@ code {
   input[type="email"],
   input[type="password"],
   input[type="url"],
+  input[type="datetime-local"],
   textarea {
     box-sizing: border-box;
     font-size: 16px;
@@ -445,7 +446,8 @@ code {
   input[type="text"],
   input[type="number"],
   input[type="email"],
-  input[type="password"] {
+  input[type="password"],
+  input[type="datetime-local"] {
     &:focus:invalid:not(:placeholder-shown),
     &:required:invalid:not(:placeholder-shown) {
       border-color: lighten($error-red, 12%);
@@ -461,6 +463,7 @@ code {
     input[type="number"],
     input[type="email"],
     input[type="password"],
+    input[type="datetime-local"],
     textarea,
     select {
       border-color: lighten($error-red, 12%);