Add datetime picker to Taken At fields (#388)

* Add DateTimePicker component and integrate into PhotoForm for date selection

src/components/DateTimePicker.tsx

@@ -0,0 +1,342 @@
+'use client';
+
+import {
+  useState,
+  useRef,
+  useMemo,
+  useCallback,
+} from 'react';
+import {
+  format,
+  parse,
+  startOfMonth,
+  endOfMonth,
+  startOfWeek,
+  endOfWeek,
+  eachDayOfInterval,
+  isSameMonth,
+  isSameDay,
+  addMonths,
+  subMonths,
+  isValid,
+} from 'date-fns';
+import { clsx } from 'clsx/lite';
+import useClickInsideOutside from '@/utility/useClickInsideOutside';
+import { useFormStatus } from 'react-dom';
+import { TbCalendar, TbChevronLeft, TbChevronRight } from 'react-icons/tb';
+
+const FORMAT_NAIVE = 'yyyy-MM-dd HH:mm:ss';
+const DAY_NAMES = ['Su', 'Mo', 'Tu', 'We', 'Th', 'Fr', 'Sa'];
+
+export type DateTimePickerType = 'utc' | 'naive';
+type DisplayMode = 'utc' | 'local';
+
+// Get short local timezone label, e.g. "EST", "PST", "UTC+5"
+const LOCAL_TZ_LABEL =
+  new Date().toLocaleTimeString('en-US', { timeZoneName: 'short' })
+    .split(' ').at(-1) ?? 'LOCAL';
+
+function parseValue(
+  value: string,
+  type: DateTimePickerType,
+  displayMode: DisplayMode,
+): Date | null {
+  if (!value) return null;
+  try {
+    if (type === 'utc') {
+      const utcDate = new Date(value);
+      if (!isValid(utcDate)) return null;
+      if (displayMode === 'local') {
+        // Return as-is; JS Date local getters will show local time
+        return utcDate;
+      }
+      // Shift UTC components into a local Date so calendar renders UTC time
+      return new Date(
+        utcDate.getUTCFullYear(),
+        utcDate.getUTCMonth(),
+        utcDate.getUTCDate(),
+        utcDate.getUTCHours(),
+        utcDate.getUTCMinutes(),
+        utcDate.getUTCSeconds(),
+      );
+    } else {
+      const d = parse(value, FORMAT_NAIVE, new Date());
+      return isValid(d) ? d : null;
+    }
+  } catch {
+    return null;
+  }
+}
+
+function formatValue(
+  displayDate: Date,
+  type: DateTimePickerType,
+  displayMode: DisplayMode,
+): string {
+  if (type === 'utc') {
+    if (displayMode === 'local') {
+      // Local Date components → JS converts to UTC in toISOString()
+      return new Date(
+        displayDate.getFullYear(),
+        displayDate.getMonth(),
+        displayDate.getDate(),
+        displayDate.getHours(),
+        displayDate.getMinutes(),
+        displayDate.getSeconds(),
+      ).toISOString();
+    }
+    // UTC mode: treat display components as UTC
+    return new Date(Date.UTC(
+      displayDate.getFullYear(),
+      displayDate.getMonth(),
+      displayDate.getDate(),
+      displayDate.getHours(),
+      displayDate.getMinutes(),
+      displayDate.getSeconds(),
+    )).toISOString();
+  }
+  return format(displayDate, FORMAT_NAIVE);
+}
+
+export default function DateTimePicker({
+  value,
+  onChange,
+  type,
+  readOnly,
+}: {
+  value: string
+  onChange?: (value: string) => void
+  type: DateTimePickerType
+  readOnly?: boolean
+}) {
+  const containerRef = useRef<HTMLDivElement>(null);
+  const { pending } = useFormStatus();
+  const isDisabled = readOnly || pending;
+
+  const [isOpen, setIsOpen] = useState(false);
+  const [viewMonth, setViewMonth] = useState(new Date());
+  const [displayMode, setDisplayMode] = useState<DisplayMode>('utc');
+
+  const parsedDate = useMemo(
+    () => parseValue(value, type, displayMode),
+    [value, type, displayMode],
+  );
+
+  useClickInsideOutside({
+    htmlElements: [containerRef],
+    onClickOutside: () => setIsOpen(false),
+    shouldListenToClicks: isOpen,
+  });
+
+  const calendarDays = useMemo(() => {
+    const start = startOfWeek(startOfMonth(viewMonth));
+    const end = endOfWeek(endOfMonth(viewMonth));
+    return eachDayOfInterval({ start, end });
+  }, [viewMonth]);
+
+  const updateDate = useCallback((newDisplayDate: Date) => {
+    onChange?.(formatValue(newDisplayDate, type, displayMode));
+  }, [onChange, type, displayMode]);
+
+  const handleDayClick = (day: Date) => {
+    const base = parsedDate ?? new Date();
+    updateDate(new Date(
+      day.getFullYear(),
+      day.getMonth(),
+      day.getDate(),
+      base.getHours(),
+      base.getMinutes(),
+      base.getSeconds(),
+    ));
+  };
+
+  const h = parsedDate?.getHours() ?? 0;
+  const m = parsedDate?.getMinutes() ?? 0;
+  const s = parsedDate?.getSeconds() ?? 0;
+
+  return (
+    <div ref={containerRef} className="relative self-start">
+      <button
+        type="button"
+        tabIndex={-1}
+        disabled={isDisabled}
+        onClick={() => {
+          if (isDisabled) return;
+          if (!isOpen && parsedDate) {
+            setViewMonth(parsedDate);
+          }
+          setIsOpen(o => !o);
+        }}
+        className="h-9"
+      >
+        <TbCalendar size={16} />
+      </button>
+      {isOpen && (
+        <div className={clsx(
+          'component-surface shadow-lg dark:shadow-xl',
+          'absolute right-0 top-full mt-1 z-10',
+          'p-3 w-60',
+          'animate-fade-in-from-top',
+        )}>
+          {/* Month navigation */}
+          <div className="flex items-center justify-between mb-2">
+            <button
+              type="button"
+              className="link"
+              onClick={() => setViewMonth(subMonths(viewMonth, 1))}
+            >
+              <TbChevronLeft size={16} />
+            </button>
+            <span className="text-sm font-medium">
+              {format(viewMonth, 'MMMM yyyy')}
+            </span>
+            <button
+              type="button"
+              className="link"
+              onClick={() => setViewMonth(addMonths(viewMonth, 1))}
+            >
+              <TbChevronRight size={16} />
+            </button>
+          </div>
+
+          {/* Day headers */}
+          <div className="grid grid-cols-7 mb-1">
+            {DAY_NAMES.map(day => (
+              <div
+                key={day}
+                className="text-center text-xs text-dim py-0.5"
+              >
+                {day}
+              </div>
+            ))}
+          </div>
+
+          {/* Calendar days */}
+          <div className="grid grid-cols-7">
+            {calendarDays.map(day => {
+              const isCurrentMonth = isSameMonth(day, viewMonth);
+              const isSelected =
+                parsedDate !== null && isSameDay(day, parsedDate);
+              return (
+                <button
+                  key={day.toISOString()}
+                  type="button"
+                  onClick={() => handleDayClick(day)}
+                  className={clsx(
+                    'link justify-center py-1 px-0! w-full rounded-sm!',
+                    !isCurrentMonth && 'text-extra-dim',
+                    isCurrentMonth && !isSelected &&
+                      'hover:bg-gray-100! dark:hover:bg-gray-800!',
+                    isSelected &&
+                      // eslint-disable-next-line max-len
+                      'bg-gray-900! dark:bg-gray-100! text-white! dark:text-black!',
+                  )}
+                >
+                  {format(day, 'd')}
+                </button>
+              );
+            })}
+          </div>
+
+          {/* Time */}
+          <div className={clsx(
+            'flex items-center justify-between',
+            'mt-2 pt-2 border-t border-gray-200 dark:border-gray-700',
+          )}>
+            <div className="flex items-center gap-1">
+              <TimeField
+                value={h}
+                max={23}
+                onChange={newH => {
+                  const base = parsedDate ?? new Date();
+                  updateDate(new Date(
+                    base.getFullYear(), base.getMonth(), base.getDate(),
+                    newH, m, s,
+                  ));
+                }}
+              />
+              <span className="text-dim select-none">:</span>
+              <TimeField
+                value={m}
+                max={59}
+                onChange={newM => {
+                  const base = parsedDate ?? new Date();
+                  updateDate(new Date(
+                    base.getFullYear(), base.getMonth(), base.getDate(),
+                    h, newM, s,
+                  ));
+                }}
+              />
+              <span className="text-dim select-none">:</span>
+              <TimeField
+                value={s}
+                max={59}
+                onChange={newS => {
+                  const base = parsedDate ?? new Date();
+                  updateDate(new Date(
+                    base.getFullYear(), base.getMonth(), base.getDate(),
+                    h, m, newS,
+                  ));
+                }}
+              />
+            </div>
+            {type === 'utc' && (
+              <button
+                type="button"
+                onClick={() => {
+                  const newMode: DisplayMode =
+                    displayMode === 'utc' ? 'local' : 'utc';
+                  const newParsed = parseValue(value, type, newMode);
+                  if (newParsed) setViewMonth(newParsed);
+                  setDisplayMode(newMode);
+                }}
+                className={clsx(
+                  'shrink-0 text-xs px-1.5! py-1!',
+                  'border font-mono',
+                  displayMode === 'local'
+                    ? 'border-gray-900 dark:border-gray-100 text-main'
+                    : 'border-gray-300 dark:border-gray-600 text-dim',
+                )}
+              >
+                {displayMode === 'local' ? LOCAL_TZ_LABEL : 'UTC'}
+              </button>
+            )}
+          </div>
+        </div>
+      )}
+    </div>
+  );
+}
+
+function TimeField({
+  value,
+  max,
+  onChange,
+}: {
+  value: number
+  max: number
+  onChange: (value: number) => void
+}) {
+  const formatted = useMemo(() => String(value).padStart(2, '0'), [value]);
+  const [draft, setDraft] = useState<string | null>(null);
+
+  return (
+    <input
+      type="text"
+      inputMode="numeric"
+      value={draft ?? formatted}
+      onChange={e => {
+        const val = e.target.value;
+        if (!/^\d{0,2}$/.test(val)) return;
+        setDraft(val);
+        const n = parseInt(val, 10);
+        if (!isNaN(n) && n >= 0 && n <= max) {
+          onChange(n);
+        }
+      }}
+      onFocus={() => setDraft(formatted)}
+      onBlur={() => setDraft(null)}
+      className="w-9! min-h-0! text-center px-1! py-1! text-xs"
+    />
+  );
+}

src/photo/form/PhotoForm.tsx

@@ -72,6 +72,7 @@ import { Albums } from '@/album';
 import FieldsetAlbum from '@/album/FieldsetAlbum';
 import Form from 'next/form';
 import { useRouter, useSearchParams } from 'next/navigation';
+import DateTimePicker from '@/components/DateTimePicker';
 
 const THUMBNAIL_SIZE = 300;
 
@@ -659,6 +660,28 @@ export default function PhotoForm({
                             formData,
                           )}
                         />;
+                      case 'takenAt':
+                        return <FieldsetWithStatus
+                          key={key}
+                          {...fieldProps}
+                          accessory={<DateTimePicker
+                            value={formData.takenAt ?? ''}
+                            onChange={fieldProps.onChange}
+                            type="utc"
+                            readOnly={fieldProps.readOnly}
+                          />}
+                        />;
+                      case 'takenAtNaive':
+                        return <FieldsetWithStatus
+                          key={key}
+                          {...fieldProps}
+                          accessory={<DateTimePicker
+                            value={formData.takenAtNaive ?? ''}
+                            onChange={fieldProps.onChange}
+                            type="naive"
+                            readOnly={fieldProps.readOnly}
+                          />}
+                        />;
                       case 'favorite':
                         return <FieldsetFavs
                           key={key}