Add deep link resolver, closes #341

lib/router.dart

@@ -12,6 +12,7 @@ import 'package:zapstore/screens/search_screen.dart';
 import 'package:zapstore/screens/updates_screen.dart';
 import 'package:zapstore/screens/profile_screen.dart';
 import 'package:zapstore/services/package_manager/package_manager.dart';
+import 'package:zapstore/services/deep_link_resolver.dart';
 
 /// Root paths for each navigation branch (used for back navigation handling)
 const kBranchRoots = ['/search', '/updates', '/profile'];
@@ -103,19 +104,11 @@ final routerProvider = Provider<GoRouter>((ref) {
   final router = GoRouter(
     navigatorKey: rootNavigatorKey,
     initialLocation: '/search',
+    // Intercept deep link URIs that GoRouter cannot match as paths.
+    // This fires before any route is rendered, eliminating the GoException
+    // flash when the app is launched via market:// or https://zapstore.dev.
+    redirect: (context, state) => resolveDeepLinkPath(state.uri),
     routes: [
-      // Top-level route for market:// intents
-      // Redirect to search branch to show with nav bar
-      GoRoute(
-        path: '/market/:packageId',
-        redirect: (context, state) {
-          final packageId = state.pathParameters['packageId'];
-          if (packageId == null || packageId.isEmpty) {
-            return '/search';
-          }
-          return '/search/app/$packageId';
-        },
-      ),
       // Single stateful shell route that handles everything
       StatefulShellRoute.indexedStack(
         builder: (context, state, navigationShell) =>

lib/services/deep_link_resolver.dart

@@ -0,0 +1,45 @@
+import 'package:flutter/foundation.dart';
+
+/// Converts a deep link URI into a router path string, or returns null if
+/// the URI is not a recognized deep link.
+///
+/// Handles:
+/// - `https://zapstore.dev/apps/{id}`
+/// - `market://details?id=com.example.app`
+/// - `market://search?q=search+query`
+String? resolveDeepLinkPath(Uri uri) {
+  // https://zapstore.dev/apps/<id>
+  if (uri.scheme == 'https' &&
+      uri.host == 'zapstore.dev' &&
+      uri.pathSegments.length == 2 &&
+      uri.pathSegments[0] == 'apps') {
+    final id = uri.pathSegments[1];
+    if (id.isNotEmpty) {
+      debugPrint('App link: app ID = $id');
+      return '/search/app/$id';
+    }
+  }
+
+  // market://details?id=com.example.app  (Google Play-style intents)
+  if (uri.scheme == 'market') {
+    if (uri.host == 'details' || uri.path == '/details') {
+      final id = uri.queryParameters['id'];
+      if (id != null && id.isNotEmpty) {
+        debugPrint('Market intent: app ID = $id');
+        return '/search/app/$id';
+      }
+    }
+
+    if (uri.host == 'search' || uri.path == '/search') {
+      final query = uri.queryParameters['q'];
+      if (query != null && query.isNotEmpty) {
+        debugPrint('Market intent: search query = $query');
+        return '/search/app/$query';
+      }
+    }
+
+    debugPrint('Market intent: unhandled URI = $uri');
+  }
+
+  return null;
+}

lib/services/deep_link_service.dart

@@ -1,10 +1,10 @@
 import 'dart:async';
 
 import 'package:app_links/app_links.dart';
-import 'package:flutter/foundation.dart';
 import 'package:go_router/go_router.dart';
 import 'package:hooks_riverpod/hooks_riverpod.dart';
 import 'package:zapstore/router.dart';
+import 'package:zapstore/services/deep_link_resolver.dart';
 
 final deepLinkServiceProvider = Provider<DeepLinkService>((ref) {
   return DeepLinkService(ref);
@@ -20,39 +20,24 @@ class DeepLinkService {
 
   GoRouter get _router => _ref.read(routerProvider);
 
-  /// Initialize the service - call once after app is ready
+  /// Initialize the service - call once after app is ready.
+  ///
+  /// The initial launch URI is not re-processed here because GoRouter's
+  /// top-level redirect already maps it to the correct path before any
+  /// screen renders. Only links received while the app is running are handled.
   Future<void> initialize() async {
     if (_initialized) return;
     _initialized = true;
 
-    // Handle initial link (app launched via intent)
-    final initialUri = await _appLinks.getInitialLink();
-    _handleUri(initialUri);
-
-    // Handle links while app is running
     _subscription = _appLinks.uriLinkStream.listen(_handleUri);
   }
 
   void _handleUri(Uri? uri) {
     if (uri == null) return;
 
-    // https://zapstore.dev/apps/<id>
-    if (uri.scheme == 'https' &&
-        uri.host == 'zapstore.dev' &&
-        uri.pathSegments.length == 2 &&
-        uri.pathSegments[0] == 'apps') {
-      final id = uri.pathSegments[1];
-      if (id.isNotEmpty) {
-        debugPrint('App link: app ID = $id');
-        _router.go('/search/app/$id');
-        return;
-      }
-    }
-
-    // market://details?id=com.example.app  (Google Play-style intents)
-    final packageId = _extractMarketPackageId(uri);
-    if (packageId != null) {
-      _router.go('/search/app/$packageId');
+    final path = resolveDeepLinkPath(uri);
+    if (path != null) {
+      _router.go(path);
     }
   }
 
@@ -60,31 +45,3 @@ class DeepLinkService {
     _subscription?.cancel();
   }
 }
-
-/// Extract package ID from a market:// URI.
-///
-/// Handles:
-/// - market://details?id=com.example.app
-/// - market://search?q=search+query
-String? _extractMarketPackageId(Uri uri) {
-  if (uri.scheme != 'market') return null;
-
-  if (uri.host == 'details' || uri.path == '/details') {
-    final id = uri.queryParameters['id'];
-    if (id != null && id.isNotEmpty) {
-      debugPrint('Market intent: app ID = $id');
-      return id;
-    }
-  }
-
-  if (uri.host == 'search' || uri.path == '/search') {
-    final query = uri.queryParameters['q'];
-    if (query != null && query.isNotEmpty) {
-      debugPrint('Market intent: search query = $query');
-      return query;
-    }
-  }
-
-  debugPrint('Market intent: unhandled URI = $uri');
-  return null;
-}