File Upload Field Input

1
2
3
4
5
6
import { type ClassValue, clsx } from "clsx";
import { twMerge } from "tailwind-merge";
 
export function cn(...inputs: ClassValue[]) {
  return twMerge(clsx(inputs));
}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
"use client";
 
import {
  forwardRef,
  useCallback,
  useEffect,
  useId,
  useRef,
  useState,
  type ChangeEvent,
  type DragEvent,
} from "react";
 
import { FileText, ImagePlus, Plus, X } from "lucide-react";
 
import { cn } from "@/lib/cn";
 
export type FileUploadFieldInputProps = Readonly<{
  label?: string;
  hint?: string;
  error?: boolean;
  errorMessage?: string;
  browseLabel?: string;
  dropLabel?: string;
  replaceLabel?: string;
  accept?: string;
  multiple?: boolean;
  maxFiles?: number;
  maxSizeBytes?: number;
  disabled?: boolean;
  required?: boolean;
  name?: string;
  containerClassName?: string;
  onFilesChange?: (files: File[]) => void;
}>;
 
type FileEntry = Readonly<{
  id: string;
  file: File;
  previewUrl?: string;
}>;
 
function formatFileSize(bytes: number): string {
  if (bytes < 1024) return `${bytes} B`;
  if (bytes < 1024 * 1024) return `${(bytes / 1024).toFixed(1)} KB`;
  return `${(bytes / (1024 * 1024)).toFixed(1)} MB`;
}
 
function isImageFile(file: File): boolean {
  return file.type.startsWith("image/") || /\.(png|jpe?g|gif|webp|svg)$/i.test(file.name);
}
 
function isPdfFile(file: File): boolean {
  return file.type === "application/pdf" || /\.pdf$/i.test(file.name);
}
 
function parseAcceptTokens(accept: string): string[] {
  return accept
    .split(",")
    .map((part) => part.trim().replace(/^\./, "").toUpperCase())
    .filter(Boolean);
}
 
function fileMatchesAccept(file: File, accept: string): boolean {
  const tokens = accept
    .split(",")
    .map((token) => token.trim().toLowerCase())
    .filter(Boolean);
  if (tokens.length === 0) return true;
 
  const fileName = file.name.toLowerCase();
  const fileType = file.type.toLowerCase();
  return tokens.some((token) => {
    if (token.startsWith(".")) return fileName.endsWith(token);
    if (token.endsWith("/*")) return fileType.startsWith(token.slice(0, -1));
    return fileType === token;
  });
}
 
function createEntry(file: File): FileEntry {
  return {
    id: `${file.name}-${file.size}-${file.lastModified}`,
    file,
    previewUrl: isImageFile(file) ? URL.createObjectURL(file) : undefined,
  };
}
 
function revokeEntryPreview(entry: FileEntry) {
  if (entry.previewUrl) URL.revokeObjectURL(entry.previewUrl);
}
 
export const FileUploadFieldInput = forwardRef<
  HTMLInputElement,
  FileUploadFieldInputProps
>(function FileUploadFieldInput(
  {
    label = "Upload document",
    hint = "PDF, PNG, or JPG up to 5 MB.",
    error = false,
    errorMessage = "Could not upload this file.",
    browseLabel = "Choose file",
    dropLabel = "Drop your file here",
    replaceLabel = "Replace file",
    accept = ".pdf,.png,.jpg,.jpeg",
    multiple = false,
    maxFiles = 3,
    maxSizeBytes = 5 * 1024 * 1024,
    disabled = false,
    required = false,
    name,
    containerClassName,
    onFilesChange,
  },
  ref,
) {
  const generatedId = useId();
  const inputId = `${generatedId}-file`;
  const hintId = `${generatedId}-hint`;
  const errorId = `${generatedId}-error`;
  const localRef = useRef<HTMLInputElement | null>(null);
  const entriesRef = useRef<FileEntry[]>([]);
  const [entries, setEntries] = useState<FileEntry[]>([]);
  const [dragging, setDragging] = useState(false);
  const [localError, setLocalError] = useState("");
  const safeMaxFiles = Number.isFinite(maxFiles)
    ? Math.max(1, Math.floor(maxFiles))
    : 3;
  const safeMaxSizeBytes = Number.isFinite(maxSizeBytes)
    ? Math.max(0, maxSizeBytes)
    : 5 * 1024 * 1024;
 
  entriesRef.current = entries;
 
  const mergeRef = useCallback(
    (node: HTMLInputElement | null) => {
      localRef.current = node;
      if (typeof ref === "function") ref(node);
      else if (ref) ref.current = node;
    },
    [ref],
  );
 
  useEffect(() => {
    return () => {
      for (const entry of entriesRef.current) revokeEntryPreview(entry);
    };
  }, []);
 
  useEffect(() => {
    const form = localRef.current?.form;
    if (!form) return;
 
    const handleReset = () => {
      for (const entry of entriesRef.current) revokeEntryPreview(entry);
      entriesRef.current = [];
      setEntries([]);
      setLocalError("");
      setDragging(false);
      onFilesChange?.([]);
    };
 
    form.addEventListener("reset", handleReset);
    return () => form.removeEventListener("reset", handleReset);
  }, [onFilesChange]);
 
  const validateAndAdd = useCallback(
    (incoming: File[]) => {
      setLocalError("");
      const validFiles: File[] = [];
 
      for (const file of incoming) {
        if (!fileMatchesAccept(file, accept)) {
          setLocalError(`"${file.name}" is not an accepted file type.`);
          continue;
        }
        if (file.size > safeMaxSizeBytes) {
          setLocalError(`"${file.name}" exceeds the size limit.`);
          continue;
        }
        validFiles.push(file);
      }
 
      if (validFiles.length === 0) return;
 
      const previous = entriesRef.current;
      const existingIds = new Set(previous.map((entry) => entry.id));
      const uniqueFiles = validFiles.filter(
        (file) => !existingIds.has(`${file.name}-${file.size}-${file.lastModified}`),
      );
      const availableSlots = multiple ? Math.max(0, safeMaxFiles - previous.length) : 1;
      const filesToAdd = uniqueFiles.slice(0, availableSlots);
 
      if (uniqueFiles.length > availableSlots) {
        setLocalError(`You can upload up to ${safeMaxFiles} ${safeMaxFiles === 1 ? "file" : "files"}.`);
      }
      if (filesToAdd.length === 0) return;
 
      const nextEntries = filesToAdd.map(createEntry);
      if (!multiple) {
        for (const entry of previous) revokeEntryPreview(entry);
      }
 
      const next = multiple ? [...previous, ...nextEntries] : nextEntries;
      entriesRef.current = next;
      setEntries(next);
      onFilesChange?.(next.map((entry) => entry.file));
    },
    [accept, multiple, onFilesChange, safeMaxFiles, safeMaxSizeBytes],
  );
 
  useEffect(() => {
    if (localRef.current && typeof DataTransfer !== "undefined") {
      const transfer = new DataTransfer();
      for (const entry of entries) transfer.items.add(entry.file);
      localRef.current.files = transfer.files;
    }
  }, [entries]);
 
  const openPicker = useCallback(() => {
    if (!disabled) localRef.current?.click();
  }, [disabled]);
 
  const handleInputChange = useCallback(
    (event: ChangeEvent<HTMLInputElement>) => {
      const list = event.target.files;
      if (!list?.length) return;
      validateAndAdd(Array.from(list));
      event.target.value = "";
    },
    [validateAndAdd],
  );
 
  const bindDrag = useCallback(
    (active: boolean) => {
      if (!disabled) setDragging(active);
    },
    [disabled],
  );
 
  const handleDrop = useCallback(
    (event: DragEvent<HTMLDivElement>) => {
      event.preventDefault();
      setDragging(false);
      if (disabled) return;
      const list = event.dataTransfer.files;
      if (!list.length) return;
      validateAndAdd(Array.from(list));
    },
    [disabled, validateAndAdd],
  );
 
  const removeFile = useCallback((id: string) => {
    const previous = entriesRef.current;
    const target = previous.find((entry) => entry.id === id);
    if (target) revokeEntryPreview(target);
    const next = previous.filter((entry) => entry.id !== id);
    entriesRef.current = next;
    setEntries(next);
    onFilesChange?.(next.map((entry) => entry.file));
    setLocalError("");
  }, [onFilesChange]);
 
  const showError = error || Boolean(localError);
  const message = localError || errorMessage;
  const hasFiles = entries.length > 0;
  const acceptTokens = parseAcceptTokens(accept);
  const maxSizeLabel = formatFileSize(safeMaxSizeBytes);
  const primaryEntry = entries[0];
  const showSinglePreview = !multiple && primaryEntry && isImageFile(primaryEntry.file);
 
  return (
    <div
      data-slot="file-upload-field-input"
      data-error={showError || undefined}
      data-filled={hasFiles || undefined}
      className={cn("w-full max-w-sm font-sans", containerClassName)}
    >
      <label htmlFor={inputId} className="mb-1.5 block w-fit cursor-pointer text-sm font-medium text-neutral-900">
        {label}
        {required ? (
          <span className="ml-0.5 text-rose-500" aria-hidden>
            *
          </span>
        ) : null}
      </label>
 
      <input
        ref={mergeRef}
        id={inputId}
        type="file"
        name={name}
        accept={accept}
        multiple={multiple}
        disabled={disabled}
        required={required && !hasFiles}
        aria-invalid={showError || undefined}
        aria-describedby={showError ? errorId : hint ? hintId : undefined}
        onChange={handleInputChange}
        className="sr-only"
      />
 
      <div
        className={cn(
          "overflow-hidden rounded-2xl border bg-white px-5 py-5 transition-[border-color] duration-200",
          showError ? "border-rose-200" : "border-neutral-100",
        )}
      >
        {!hasFiles ? (
          <div className="space-y-4">
            <div
              role="button"
              tabIndex={disabled ? -1 : 0}
              aria-label={dropLabel}
              onKeyDown={(event) => {
                if (disabled) return;
                if (event.key === "Enter" || event.key === " ") {
                  event.preventDefault();
                  openPicker();
                }
              }}
              onClick={openPicker}
              onDragEnter={(event) => {
                event.preventDefault();
                bindDrag(true);
              }}
              onDragOver={(event) => {
                event.preventDefault();
                bindDrag(true);
              }}
              onDragLeave={(event) => {
                event.preventDefault();
                if (!event.currentTarget.contains(event.relatedTarget as Node)) {
                  bindDrag(false);
                }
              }}
              onDrop={handleDrop}
              className={cn(
                "group relative aspect-[4/3] cursor-pointer overflow-hidden rounded-xl border outline-none ring-0 transition-[border-color,background-color] duration-200 focus:border-neutral-900 focus:ring-0",
                dragging && !showError && "border-neutral-900 bg-neutral-50",
                showError && "border-rose-300 bg-rose-50/40",
                !dragging && !showError && "border-neutral-100 bg-neutral-50 hover:border-neutral-300 hover:bg-neutral-50/80",
                disabled && "cursor-not-allowed opacity-60",
              )}
            >
              <div
                aria-hidden
                className="absolute inset-0 grid grid-cols-3 grid-rows-3"
              >
                {Array.from({ length: 9 }, (_, index) => (
                  <div
                    key={`grid-${index}`}
                    className="border border-neutral-100/90"
                  />
                ))}
              </div>
 
              <span
                aria-hidden
                className="absolute top-3 left-3 size-5 border-t-2 border-l-2 border-neutral-300 transition-colors duration-200 group-hover:border-neutral-500"
              />
              <span
                aria-hidden
                className="absolute top-3 right-3 size-5 border-t-2 border-r-2 border-neutral-300 transition-colors duration-200 group-hover:border-neutral-500"
              />
              <span
                aria-hidden
                className="absolute bottom-3 left-3 size-5 border-b-2 border-l-2 border-neutral-300 transition-colors duration-200 group-hover:border-neutral-500"
              />
              <span
                aria-hidden
                className="absolute right-3 bottom-3 size-5 border-r-2 border-b-2 border-neutral-300 transition-colors duration-200 group-hover:border-neutral-500"
              />
 
              <div className="absolute inset-0 flex flex-col items-center justify-center px-6 text-center">
                <span
                  className={cn(
                    "mb-3 flex size-12 items-center justify-center rounded-xl border border-neutral-200 bg-white text-neutral-600 transition-[border-color,transform] duration-200",
                    dragging && "scale-105 border-neutral-900 text-neutral-900",
                    !dragging && "group-hover:border-neutral-400 group-hover:text-neutral-900",
                  )}
                >
                  <ImagePlus size={22} strokeWidth={1.75} aria-hidden />
                </span>
 
                <span className="font-serif text-lg text-neutral-900">
                  {dragging ? "Release to upload" : dropLabel}
                </span>
                <span className="mt-1 text-sm text-neutral-500">
                  Drag & drop or click anywhere
                </span>
              </div>
            </div>
 
            <div className="flex items-start justify-between gap-3">
              <div className="min-w-0">
                <p className="text-sm font-medium text-neutral-400">
                  No file selected
                </p>
                <p className="mt-0.5 text-xs text-neutral-500">
                  {acceptTokens.join(", ")} · max {maxSizeLabel}
                  {multiple ? ` · up to ${safeMaxFiles} files` : ""}
                </p>
              </div>
 
              {!disabled ? (
                <button
                  type="button"
                  onClick={(event) => {
                    event.stopPropagation();
                    openPicker();
                  }}
                  className="inline-flex h-9 shrink-0 cursor-pointer items-center rounded-lg bg-neutral-900 px-4 text-sm font-medium text-white transition-opacity hover:opacity-90"
                >
                  {browseLabel}
                </button>
              ) : null}
            </div>
 
            <div className="flex flex-wrap gap-1.5">
              {acceptTokens.map((token) => (
                <span
                  key={token}
                  className="rounded-full border border-neutral-200 bg-neutral-50 px-2.5 py-1 text-[10px] font-medium tracking-wide text-neutral-600 uppercase"
                >
                  {token}
                </span>
              ))}
            </div>
          </div>
        ) : showSinglePreview && primaryEntry ? (
          <div className="space-y-4">
            <div className="relative overflow-hidden rounded-xl border border-neutral-100 bg-neutral-50">
              {/* eslint-disable-next-line @next/next/no-img-element */}
              <img
                src={primaryEntry.previewUrl}
                alt={primaryEntry.file.name}
                className="aspect-[4/3] w-full object-cover"
              />
              {!disabled ? (
                <button
                  type="button"
                  aria-label={`Remove ${primaryEntry.file.name}`}
                  onClick={() => removeFile(primaryEntry.id)}
                  className="absolute top-2.5 right-2.5 flex size-8 cursor-pointer items-center justify-center rounded-full border border-neutral-200 bg-white text-neutral-600 transition-colors hover:border-neutral-300 hover:text-neutral-900"
                >
                  <X size={14} strokeWidth={2} aria-hidden />
                </button>
              ) : null}
            </div>
 
            <div className="flex items-start justify-between gap-3">
              <div className="min-w-0">
                <p className="truncate text-sm font-medium text-neutral-900">
                  {primaryEntry.file.name}
                </p>
                <p className="mt-0.5 text-xs text-neutral-500">
                  {formatFileSize(primaryEntry.file.size)} · Ready to upload
                </p>
              </div>
              {!disabled ? (
                <button
                  type="button"
                  onClick={openPicker}
                  className="shrink-0 cursor-pointer text-sm font-medium text-neutral-900 underline-offset-2 hover:underline"
                >
                  {replaceLabel}
                </button>
              ) : null}
            </div>
          </div>
        ) : (
          <div className="space-y-3">
            <ul className="space-y-2">
              {entries.map((entry) => (
                <li
                  key={entry.id}
                  className="flex items-center gap-3 rounded-xl border border-neutral-100 bg-neutral-50/80 p-2.5"
                >
                  {entry.previewUrl ? (
                    <div className="size-12 shrink-0 overflow-hidden rounded-lg border border-neutral-100 bg-white">
                      {/* eslint-disable-next-line @next/next/no-img-element */}
                      <img
                        src={entry.previewUrl}
                        alt=""
                        className="size-full object-cover"
                      />
                    </div>
                  ) : (
                    <span className="flex size-12 shrink-0 items-center justify-center rounded-lg border border-neutral-100 bg-white text-neutral-600">
                      {isPdfFile(entry.file) ? (
                        <FileText size={18} strokeWidth={1.75} aria-hidden />
                      ) : (
                        <ImagePlus size={18} strokeWidth={1.75} aria-hidden />
                      )}
                    </span>
                  )}
 
                  <div className="min-w-0 flex-1">
                    <p className="truncate text-sm font-medium text-neutral-900">
                      {entry.file.name}
                    </p>
                    <p className="mt-0.5 text-xs text-neutral-500">
                      {formatFileSize(entry.file.size)}
                    </p>
                  </div>
 
                  {!disabled ? (
                    <button
                      type="button"
                      aria-label={`Remove ${entry.file.name}`}
                      onClick={() => removeFile(entry.id)}
                      className="flex size-8 shrink-0 cursor-pointer items-center justify-center rounded-lg border border-neutral-200 bg-white text-neutral-500 transition-colors hover:border-neutral-300 hover:text-neutral-900"
                    >
                      <X size={14} strokeWidth={2} aria-hidden />
                    </button>
                  ) : null}
                </li>
              ))}
            </ul>
 
            {multiple && entries.length < safeMaxFiles && !disabled ? (
              <button
                type="button"
                onClick={openPicker}
                className="flex h-10 w-full cursor-pointer items-center justify-center gap-2 rounded-xl border border-dashed border-neutral-200 bg-white text-sm font-medium text-neutral-700 transition-colors hover:border-neutral-400 hover:bg-neutral-50"
              >
                <Plus size={16} strokeWidth={2} aria-hidden />
                Add another file
              </button>
            ) : null}
 
            {!multiple && !disabled ? (
              <button
                type="button"
                onClick={openPicker}
                className="text-sm font-medium text-neutral-900 underline-offset-2 hover:underline"
              >
                {replaceLabel}
              </button>
            ) : null}
          </div>
        )}
      </div>
 
      {showError ? (
        <p id={errorId} role="alert" className="mt-1.5 text-xs text-rose-600">
          {message}
        </p>
      ) : hint ? (
        <p id={hintId} className="mt-1.5 text-xs text-neutral-500">
          {hint}
        </p>
      ) : null}
    </div>
  );
});
 
FileUploadFieldInput.displayName = "FileUploadFieldInput";