[linting_tool] Implement exporting profiles (#869)

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,
 }