add structure

lib/config.dart

@@ -0,0 +1,48 @@
+import 'package:flutter/material.dart';
+import 'package:logging/logging.dart';
+
+enum Flavor { DEV, STAGING, PRODUCTION, LOCAL }
+const FlavorNames = ["Development", "Staging", "Production", "Local"];
+
+class Config {
+  static Config _instance;
+
+  final Flavor flavor;
+  final String name;
+  final Color color;
+  final String apiURL;
+  final String reportURL;
+  final Level level;
+  final String reportProjectID;
+
+  factory Config(
+      {@required Flavor flavor,
+      @required String apiURL,
+      @required String reportURL,
+      @required String reportProjectID,
+      Color color: Colors.blue,
+      Level level: Level.SEVERE}) {
+    _instance ??= Config._internal(flavor, FlavorNames[flavor.index], color,
+        apiURL, reportURL, level, reportProjectID);
+
+    Logger.root.level = level;
+    Logger.root.onRecord.listen((record) {
+      print(
+          '${record.level.name}: ${record.time}: ${record.loggerName}: ${record.message}');
+    });
+
+    return _instance;
+  }
+
+  Config._internal(this.flavor, this.name, this.color, this.apiURL,
+      this.reportURL, this.level, this.reportProjectID);
+
+  static Config get instance {
+    return _instance;
+  }
+
+  static bool isProduction() => _instance.flavor == Flavor.PRODUCTION;
+  static bool isDevelopment() => _instance.flavor == Flavor.DEV;
+  static bool isStaging() => _instance.flavor == Flavor.STAGING;
+  static bool isLocal() => _instance.flavor == Flavor.LOCAL;
+}