[verified] Publish ReelBox source under GPLv3

lib/media/download_button.dart

@@ -0,0 +1,97 @@
+import 'package:flutter/material.dart';
+
+import '../data/models.dart';
+import '../state/app_state.dart';
+import 'download_service.dart';
+import 'downloads_page.dart';
+
+typedef EnqueueDownload = Future<void> Function({
+  required TitleRecord title,
+  required MediaSource source,
+  EpisodeRecord? episode,
+});
+
+/// The primary action always queues inside Reelbox, never an external app.
+class DownloadButton extends StatefulWidget {
+  const DownloadButton({
+    super.key,
+    required this.title,
+    required this.source,
+    this.episode,
+    this.enqueue,
+    this.openDownloads,
+  });
+
+  final TitleRecord title;
+  final MediaSource source;
+  final EpisodeRecord? episode;
+  final EnqueueDownload? enqueue;
+  final void Function(BuildContext context)? openDownloads;
+
+  @override
+  State<DownloadButton> createState() => _DownloadButtonState();
+}
+
+class _DownloadButtonState extends State<DownloadButton> {
+  bool _starting = false;
+
+  Future<void> _download() async {
+    if (_starting) return;
+    setState(() => _starting = true);
+    try {
+      final host = Uri.tryParse(widget.source.url)?.host.toLowerCase() ?? '';
+      if (RegExp(
+            'youtube|embed',
+            caseSensitive: false,
+          ).hasMatch(widget.source.type) ||
+          host == 'youtu.be' ||
+          host == 'youtube.com' ||
+          host.endsWith('.youtube.com')) {
+        throw UnsupportedError(
+          tr(
+            context,
+            'Embedded sources cannot be downloaded. Choose a direct media source.',
+            'منابع جاسازی‌شده قابل دانلود نیستند. یک منبع رسانه مستقیم انتخاب کنید.',
+          ),
+        );
+      }
+      await (widget.enqueue ?? DownloadService.instance.enqueue)(
+        title: widget.title,
+        source: widget.source,
+        episode: widget.episode,
+      );
+      if (!mounted) return;
+      if (widget.openDownloads case final open?) {
+        open(context);
+      } else {
+        Navigator.of(
+          context,
+        ).push(MaterialPageRoute<void>(builder: (_) => const DownloadsPage()));
+      }
+    } catch (error) {
+      if (mounted) {
+        ScaffoldMessenger.of(context).showSnackBar(
+          SnackBar(
+            content: Text(
+              '${tr(context, 'Could not start download', 'شروع دانلود ممکن نشد')}: ${downloadErrorMessage(error)}',
+            ),
+          ),
+        );
+      }
+    } finally {
+      if (mounted) setState(() => _starting = false);
+    }
+  }
+
+  @override
+  Widget build(BuildContext context) => FilledButton.icon(
+    onPressed: widget.source.url.isEmpty || _starting ? null : _download,
+    icon: _starting
+        ? const SizedBox.square(
+            dimension: 18,
+            child: CircularProgressIndicator(strokeWidth: 2),
+          )
+        : const Icon(Icons.download_outlined),
+    label: Text(tr(context, 'Download in Reelbox', 'دانلود در ریلباکس')),
+  );
+}