web_open_file_picker.dart

import 'dart:js_interop';
import 'dart:typed_data';
import 'package:web/web.dart' as web;

void webOpenFilePicker(
  Function(web.File f, Uint8List bytes) hookSuccess,
  Function(String) hookError,
  bool openFileInBrowser,
) {
  final input =
      web.HTMLInputElement()
        ..type = 'file'
        ..accept = '*/*'; // Accept all file types

  input.click();

  input.onChange.listen((event) {
    final files = input.files;
    if (files != null && files.length > 0) {
      final file = files.item(0)!; // Get the first file
      final reader = web.FileReader();

      // Log file size for debugging
      print("Selected file: ${file.name}, Size: ${file.size} bytes");

      // Set onload callback
      reader.onload =
          (web.Event event) {
            if (reader.result != null) {
              final arrayBuffer = reader.result as ByteBuffer;
              final bytes = Uint8List.view(arrayBuffer);

              if (openFileInBrowser) {
                // Try to open the file in a new tab
                final url = web.URL.createObjectURL(file);
                final opened = web.window.open(url, '_blank');
                if (opened == null) {
                  _forceDownload(file, url);
                }
              }
              hookSuccess(file, bytes);
            } else {
              hookError('reader.result is null');
            }
          }.toJS;

      // Set onerror callback with better diagnostics
      reader.onerror =
          (web.Event error) {
            hookError(
              "Error details: ${reader.error?.toString() ?? 'No details'}",
            );
          }.toJS;

      // Start reading the file as ArrayBuffer
      reader.readAsArrayBuffer(file);
    }
  });
}

// Fallback to force download if opening fails
void _forceDownload(web.File file, String url) {
  final anchor =
      web.HTMLAnchorElement()
        ..href = url
        ..download = file.name
        ..click();
  web.URL.revokeObjectURL(url); // Clean up
}