♻️ Better draft, post saving and auto restore hint

lib/widgets/post/compose_dialog.dart

@@ -1,7 +1,10 @@
 import 'package:flutter/material.dart';
+import 'package:flutter_hooks/flutter_hooks.dart';
 import 'package:hooks_riverpod/hooks_riverpod.dart';
+import 'package:island/models/file.dart';
 import 'package:island/models/post.dart';
 import 'package:island/screens/posts/compose.dart';
+import 'package:island/services/compose_storage_db.dart';
 import 'package:island/widgets/post/compose_card.dart';
 
 /// A dialog that wraps PostComposeCard for easy use in dialogs.
@@ -30,17 +33,159 @@ class PostComposeDialog extends HookConsumerWidget {
 
   @override
   Widget build(BuildContext context, WidgetRef ref) {
+    final drafts = ref.watch(composeStorageNotifierProvider);
+    final restoredInitialState = useState<PostComposeInitialState?>(null);
+    final prompted = useState(false);
+
+    useEffect(() {
+      if (!prompted.value && originalPost == null && drafts.isNotEmpty) {
+        prompted.value = true;
+        WidgetsBinding.instance.addPostFrameCallback((_) {
+          _showRestoreDialog(ref, restoredInitialState);
+        });
+      }
+      return null;
+    }, [drafts, prompted.value]);
+
     return Dialog(
       insetPadding: const EdgeInsets.all(16),
       child: ConstrainedBox(
         constraints: const BoxConstraints(maxWidth: 600, maxHeight: 700),
         child: PostComposeCard(
           originalPost: originalPost,
-          initialState: initialState,
+          initialState: restoredInitialState.value ?? initialState,
           onCancel: () => Navigator.of(context).pop(),
           onSubmit: (post) => Navigator.of(context).pop(post),
         ),
       ),
     );
   }
+
+  Future<void> _showRestoreDialog(
+    WidgetRef ref,
+    ValueNotifier<PostComposeInitialState?> restoredInitialState,
+  ) async {
+    final drafts = ref.read(composeStorageNotifierProvider);
+    if (drafts.isNotEmpty) {
+      final latestDraft = drafts.values.last;
+
+      final restore = await showDialog<bool>(
+        context: ref.context,
+        builder:
+            (context) => AlertDialog(
+              title: const Text('Restore Draft'),
+              content: Column(
+                mainAxisSize: MainAxisSize.min,
+                crossAxisAlignment: CrossAxisAlignment.start,
+                children: [
+                  const Text('A draft was found. Do you want to restore it?'),
+                  const SizedBox(height: 16),
+                  _buildCompactDraftPreview(context, latestDraft),
+                ],
+              ),
+              actions: [
+                TextButton(
+                  onPressed: () => Navigator.of(context).pop(false),
+                  child: const Text('No'),
+                ),
+                TextButton(
+                  onPressed: () => Navigator.of(context).pop(true),
+                  child: const Text('Yes'),
+                ),
+              ],
+            ),
+      );
+      if (restore == true) {
+        // Delete the old draft
+        await ref
+            .read(composeStorageNotifierProvider.notifier)
+            .deleteDraft(latestDraft.id);
+        restoredInitialState.value = PostComposeInitialState(
+          title: latestDraft.title,
+          description: latestDraft.description,
+          content: latestDraft.content,
+          visibility: latestDraft.visibility,
+          attachments:
+              latestDraft.attachments
+                  .map((e) => UniversalFile.fromAttachment(e))
+                  .toList(),
+        );
+      }
+    }
+  }
+
+  Widget _buildCompactDraftPreview(BuildContext context, SnPost draft) {
+    return Container(
+      padding: const EdgeInsets.all(12),
+      decoration: BoxDecoration(
+        color: Theme.of(context).colorScheme.surface,
+        borderRadius: BorderRadius.circular(8),
+        border: Border.all(
+          color: Theme.of(context).colorScheme.outline.withOpacity(0.3),
+        ),
+      ),
+      child: Column(
+        crossAxisAlignment: CrossAxisAlignment.start,
+        children: [
+          Row(
+            children: [
+              Icon(
+                Icons.description,
+                size: 16,
+                color: Theme.of(context).colorScheme.primary,
+              ),
+              const SizedBox(width: 8),
+              Text(
+                'Draft',
+                style: Theme.of(context).textTheme.labelMedium?.copyWith(
+                  color: Theme.of(context).colorScheme.primary,
+                ),
+              ),
+            ],
+          ),
+          const SizedBox(height: 8),
+          if (draft.title?.isNotEmpty ?? false)
+            Text(
+              draft.title!,
+              style: TextStyle(
+                fontWeight: FontWeight.w500,
+                fontSize: 14,
+                color: Theme.of(context).colorScheme.onSurface,
+              ),
+              maxLines: 1,
+              overflow: TextOverflow.ellipsis,
+            ),
+          if (draft.content?.isNotEmpty ?? false)
+            Text(
+              draft.content!,
+              style: TextStyle(
+                fontSize: 12,
+                color: Theme.of(context).colorScheme.onSurfaceVariant,
+              ),
+              maxLines: 2,
+              overflow: TextOverflow.ellipsis,
+            ),
+          if (draft.attachments.isNotEmpty)
+            Row(
+              mainAxisSize: MainAxisSize.min,
+              children: [
+                Icon(
+                  Icons.attach_file,
+                  size: 12,
+                  color: Theme.of(context).colorScheme.secondary,
+                ),
+                const SizedBox(width: 4),
+                Text(
+                  '${draft.attachments.length} attachment${draft.attachments.length > 1 ? 's' : ''}',
+                  style: TextStyle(
+                    color: Theme.of(context).colorScheme.secondary,
+                    fontSize: 11,
+                  ),
+                ),
+              ],
+            ),
+        ],
+      ),
+    );
+  }
 }