feat: add model download screen and gate app on model presence

Adds a one-time download flow for the on-device Gemma 2B model (~1.1 GB) with a progress bar, partial-download cleanup, and automatic navigation to the app shell once the file is verified. App.dart now gates on modelPresentProvider instead of onboarding state.
2026-04-26 14:42:39 +10:00
parent ea412d6fe9
commit e464c5621e
4 changed files with 275 additions and 5 deletions
@@ -0,0 +1,167 @@
+import 'package:flutter/material.dart';
+import 'package:flutter_riverpod/flutter_riverpod.dart';
+import '../../core/providers/model_download_provider.dart';
+
+class ModelDownloadScreen extends ConsumerWidget {
+  const ModelDownloadScreen({super.key});
+
+  @override
+  Widget build(BuildContext context, WidgetRef ref) {
+    final downloadState = ref.watch(modelDownloadNotifierProvider);
+
+    return Scaffold(
+      body: SafeArea(
+        child: Padding(
+          padding: const EdgeInsets.all(32),
+          child: downloadState.when(
+            data: (progress) => progress == 0.0
+                ? _IdleView(
+                    onDownload: () => ref
+                        .read(modelDownloadNotifierProvider.notifier)
+                        .startDownload(),
+                  )
+                : _DownloadingView(progress: progress),
+            loading: () => const Center(child: CircularProgressIndicator()),
+            error: (e, _) => _ErrorView(
+              error: e.toString(),
+              onRetry: () {
+                ref.read(modelDownloadNotifierProvider.notifier).reset();
+              },
+            ),
+          ),
+        ),
+      ),
+    );
+  }
+}
+
+class _IdleView extends StatelessWidget {
+  const _IdleView({required this.onDownload});
+
+  final VoidCallback onDownload;
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      mainAxisAlignment: MainAxisAlignment.center,
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      children: [
+        Icon(
+          Icons.auto_awesome,
+          size: 64,
+          color: Theme.of(context).colorScheme.primary,
+        ),
+        const SizedBox(height: 24),
+        Text(
+          'On-device AI',
+          style: Theme.of(context).textTheme.headlineSmall,
+          textAlign: TextAlign.center,
+        ),
+        const SizedBox(height: 12),
+        Text(
+          'DailyYou uses an on-device AI model to spot patterns in your moods '
+          'and behaviour. Your data never leaves your phone.',
+          style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                color: Theme.of(context).colorScheme.onSurfaceVariant,
+              ),
+          textAlign: TextAlign.center,
+        ),
+        const SizedBox(height: 8),
+        Text(
+          'The model is ~1.1 GB and only needs to be downloaded once.',
+          style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                color: Theme.of(context).colorScheme.outline,
+              ),
+          textAlign: TextAlign.center,
+        ),
+        const SizedBox(height: 40),
+        FilledButton.icon(
+          onPressed: onDownload,
+          icon: const Icon(Icons.download),
+          label: const Text('Download model'),
+        ),
+      ],
+    );
+  }
+}
+
+class _DownloadingView extends StatelessWidget {
+  const _DownloadingView({required this.progress});
+
+  final double progress;
+
+  @override
+  Widget build(BuildContext context) {
+    final pct = (progress * 100).toStringAsFixed(0);
+    final done = progress >= 1.0;
+
+    return Column(
+      mainAxisAlignment: MainAxisAlignment.center,
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      children: [
+        Icon(
+          done ? Icons.check_circle : Icons.downloading,
+          size: 64,
+          color: done
+              ? Theme.of(context).colorScheme.primary
+              : Theme.of(context).colorScheme.secondary,
+        ),
+        const SizedBox(height: 24),
+        Text(
+          done ? 'Ready!' : 'Downloading…',
+          style: Theme.of(context).textTheme.headlineSmall,
+          textAlign: TextAlign.center,
+        ),
+        const SizedBox(height: 24),
+        LinearProgressIndicator(value: progress),
+        const SizedBox(height: 8),
+        Text(
+          done ? 'Model downloaded successfully.' : '$pct% — keep the app open',
+          style: Theme.of(context).textTheme.bodySmall?.copyWith(
+                color: Theme.of(context).colorScheme.outline,
+              ),
+          textAlign: TextAlign.center,
+        ),
+      ],
+    );
+  }
+}
+
+class _ErrorView extends StatelessWidget {
+  const _ErrorView({required this.error, required this.onRetry});
+
+  final String error;
+  final VoidCallback onRetry;
+
+  @override
+  Widget build(BuildContext context) {
+    return Column(
+      mainAxisAlignment: MainAxisAlignment.center,
+      crossAxisAlignment: CrossAxisAlignment.stretch,
+      children: [
+        Icon(Icons.error_outline,
+            size: 64, color: Theme.of(context).colorScheme.error),
+        const SizedBox(height: 24),
+        Text(
+          'Download failed',
+          style: Theme.of(context).textTheme.headlineSmall,
+          textAlign: TextAlign.center,
+        ),
+        const SizedBox(height: 8),
+        Text(
+          'Check your connection and try again.',
+          style: Theme.of(context).textTheme.bodyMedium?.copyWith(
+                color: Theme.of(context).colorScheme.onSurfaceVariant,
+              ),
+          textAlign: TextAlign.center,
+        ),
+        const SizedBox(height: 40),
+        FilledButton.icon(
+          onPressed: onRetry,
+          icon: const Icon(Icons.refresh),
+          label: const Text('Try again'),
+        ),
+      ],
+    );
+  }
+}