[linting_tool] Implement exporting profiles (#869)

experimental/linting_tool/lib/app.dart

@@ -11,6 +11,8 @@ import 'package:linting_tool/routes.dart' as routes;
 import 'package:provider/provider.dart';
 import 'package:http/http.dart' as http;
 
+final client = http.Client();
+
 class LintingTool extends StatefulWidget {
   const LintingTool({Key? key}) : super(key: key);
 
@@ -26,10 +28,10 @@ class _LintingToolState extends State<LintingTool> {
     return MultiProvider(
       providers: [
         ChangeNotifierProvider<RuleStore>(
-          create: (context) => RuleStore(http.Client()),
+          create: (context) => RuleStore(client),
         ),
         ChangeNotifierProvider<ProfilesStore>(
-          create: (context) => ProfilesStore(),
+          create: (context) => ProfilesStore(client),
         ),
       ],
       child: MaterialApp(

experimental/linting_tool/lib/model/profiles_store.dart

@@ -2,16 +2,26 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'dart:convert';
 import 'dart:developer';
+import 'dart:io';
+import 'dart:typed_data';
 import 'package:flutter/material.dart';
+import 'package:json2yaml/json2yaml.dart';
 import 'package:linting_tool/model/profile.dart';
 import 'package:linting_tool/model/rule.dart';
 import 'package:linting_tool/repository/hive_service.dart';
+import 'package:linting_tool/repository/repository.dart';
+import 'package:http/http.dart' as http;
+import 'package:file_selector/file_selector.dart' as file_selector;
+import 'package:yaml/yaml.dart';
 
 const _boxName = 'rules_profile';
 
 class ProfilesStore extends ChangeNotifier {
-  ProfilesStore() {
+  late final Repository repository;
+  ProfilesStore(http.Client httpClient) {
+    repository = Repository(httpClient);
     fetchSavedProfiles();
   }
   bool _isLoading = true;
@@ -66,4 +76,84 @@ class ProfilesStore extends ChangeNotifier {
       await fetchSavedProfiles();
     });
   }
+
+  Future<bool> exportProfileFile(
+    RulesProfile profile, {
+    RulesStyle rulesStyle = RulesStyle.booleanMap,
+  }) async {
+    _isLoading = true;
+    notifyListeners();
+
+    var resultSaved = false;
+
+    try {
+      var templateFileData = await repository.getTemplateFile();
+
+      String newYamlFile =
+          _prepareYamlFile(profile, templateFileData, rulesStyle);
+
+      resultSaved = await _saveFileToDisk(newYamlFile);
+    } on SocketException catch (e) {
+      log(e.toString());
+      _error = 'Check internet connection.';
+      resultSaved = false;
+    } on Exception catch (e) {
+      log(e.toString());
+    }
+
+    _isLoading = false;
+    notifyListeners();
+
+    return resultSaved;
+  }
+
+  Future<bool> _saveFileToDisk(String newYamlFile) async {
+    const name = 'analysis_options.yaml';
+
+    /// Get file path using file picker.
+    var savePath = await file_selector.getSavePath(
+      suggestedName: name,
+    );
+
+    final data = Uint8List.fromList(newYamlFile.codeUnits);
+    final file = file_selector.XFile.fromData(data, name: name);
+
+    /// Save file to disk if path was provided.
+    if (savePath != null) {
+      file.saveTo(savePath);
+      return true;
+    }
+
+    var errorMessage = 'File path not found.';
+    _error = errorMessage;
+    throw Exception(errorMessage);
+  }
+
+  String _prepareYamlFile(
+      RulesProfile profile, YamlMap templateFile, RulesStyle rulesStyle) {
+    var rules = profile.rules.map((e) => e.name).toList();
+
+    var rulesData =
+        json.decode(json.encode(templateFile)) as Map<String, dynamic>;
+
+    /// Add rules to existing template according to formatting style.
+    if (rulesStyle == RulesStyle.booleanMap) {
+      var rulesMap = Map.fromEntries(
+        rules.map(
+          (e) => MapEntry(e, true),
+        ),
+      );
+      rulesData.update('linter', (dynamic value) => {'rules': rulesMap});
+    } else {
+      rulesData.update('linter', (dynamic value) => {'rules': rules});
+    }
+
+    return json2yaml(rulesData, yamlStyle: YamlStyle.pubspecYaml);
+  }
+}
+
+/// Formatting style for rules.
+enum RulesStyle {
+  list,
+  booleanMap,
 }

experimental/linting_tool/lib/pages/saved_lints_page.dart

@@ -45,7 +45,7 @@ class SavedLintsPage extends StatelessWidget {
               ),
               itemCount: profilesStore.savedProfiles.length,
               cacheExtent: 5,
-              itemBuilder: (context, index) {
+              itemBuilder: (itemBuilderContext, index) {
                 var profile = profilesStore.savedProfiles[index];
                 return ListTile(
                   title: Text(
@@ -74,10 +74,21 @@ class SavedLintsPage extends StatelessWidget {
                       ),
                       PopupMenuButton<String>(
                         icon: const Icon(Icons.more_vert),
-                        onSelected: (value) {
+                        onSelected: (value) async {
                           switch (value) {
                             case 'Export file':
-                              // TODO(abd99): Implement exporting files.
+                              // TODO(abd99): Add option to select formatting style.
+
+                              var saved = await profilesStore
+                                  .exportProfileFile(profile);
+
+                              if (!saved) {
+                                _showSnackBar(
+                                  context,
+                                  profilesStore.error ?? 'Failed to save file.',
+                                );
+                              }
+
                               break;
                             case 'Delete':
                               profilesStore.deleteProfile(profile);
@@ -123,4 +134,12 @@ class SavedLintsPage extends StatelessWidget {
       },
     );
   }
+
+  void _showSnackBar(BuildContext context, String data) {
+    ScaffoldMessenger.of(context).showSnackBar(
+      SnackBar(
+        content: Text(data),
+      ),
+    );
+  }
 }

experimental/linting_tool/lib/repository/api_provider.dart

@@ -5,6 +5,7 @@
 import 'dart:convert';
 import 'package:http/http.dart' as http;
 import 'package:linting_tool/model/rule.dart';
+import 'package:yaml/yaml.dart';
 
 class APIProvider {
   final _baseURL = 'https://dart-lang.github.io/linter';
@@ -12,7 +13,7 @@ class APIProvider {
   APIProvider(this.httpClient);
 
   Future<List<Rule>> getRulesList() async {
-    http.Response response =
+    final response =
         await httpClient.get(Uri.parse('$_baseURL//lints/machine/rules.json'));
 
     if (response.statusCode == 200) {
@@ -26,4 +27,14 @@ class APIProvider {
       throw Exception('Failed to load rules');
     }
   }
+
+  Future<YamlMap> getTemplateFile() async {
+    final response = await httpClient.get(Uri.parse(
+        'https://raw.githubusercontent.com/flutter/flutter/master/packages/flutter_tools/templates/app_shared/analysis_options.yaml.tmpl'));
+    if (response.statusCode == 200) {
+      return loadYaml(response.body) as YamlMap;
+    } else {
+      throw Exception('Failed to load template file');
+    }
+  }
 }

experimental/linting_tool/lib/repository/repository.dart

@@ -5,6 +5,7 @@
 import 'package:linting_tool/model/rule.dart';
 import 'package:linting_tool/repository/api_provider.dart';
 import 'package:http/http.dart' as http;
+import 'package:yaml/yaml.dart';
 
 class Repository {
   late final APIProvider _apiProvider;
@@ -14,4 +15,6 @@ class Repository {
   }
 
   Future<List<Rule>> getRulesList() => _apiProvider.getRulesList();
+
+  Future<YamlMap> getTemplateFile() => _apiProvider.getTemplateFile();
 }