Add class DefaultPathProvider

lib/settings/path.dart

@@ -0,0 +1,66 @@
+// This source code is a part of Project Violet.
+// Copyright (C) 2020-2023. violet-team. Licensed under the Apache-2.0 License.
+
+import 'dart:io';
+
+import 'package:path_provider/path_provider.dart';
+import 'package:sqflite/sqflite.dart';
+import 'package:violet/log/log.dart';
+
+class DefaultPathProvider {
+  static Future<String> getHomeDirectory() async{
+    var home = '';
+    if(Platform.isLinux){
+      Platform.environment.forEach((key, value) {
+        if(key == 'HOME'){
+          home = value;
+        }
+      });
+      return home;
+    }
+    Logger.error('[getHomeDirectory] unsupported os');
+    throw Error();
+  }
+  static Future<String> getBaseDirectory() async {
+    if(Platform.isAndroid){
+      return '${(await getApplicationDocumentsDirectory()).path}';
+    } else if(Platform.isIOS){
+      return '${(await getDatabasesPath())}';
+    } else if(Platform.isLinux){
+      return '${(await getHomeDirectory())}/.violet';
+    }
+    Logger.error('[getBaseDirectory] unsupported os');
+    throw Error();
+  }
+  static Future<String> getDocumentsDirectory() async {
+    if(Platform.isAndroid || Platform.isIOS){
+      return '${(await getApplicationDocumentsDirectory()).path}';
+    } else if(Platform.isLinux){
+      return '${(await getHomeDirectory())}/.violet';
+    }
+    Logger.error('[getDocumentsDirectory] unsupported os');
+    throw Error();
+  }
+  static Future<String> getSupportDirectory() async {
+    if(Platform.isAndroid){
+      return '${(await getApplicationDocumentsDirectory()).path}';
+    } else if(Platform.isIOS){
+      return '${(await getApplicationSupportDirectory()).path}';
+    } else if(Platform.isLinux){
+      return '${(await getHomeDirectory())}/.violet';
+    }
+    Logger.error('[getSupportDirectory] unsupported os');
+    throw Error();
+  }
+  static Future<String> getExportDirectory() async {
+    if(Platform.isAndroid){
+      return '${(await getExternalStorageDirectory())}';
+    } else if(Platform.isIOS){
+      return '${(await getApplicationSupportDirectory()).path}';
+    } else if(Platform.isLinux){
+      return '${(await getHomeDirectory())}/.violet';
+    }
+    Logger.error('[getExportDirectory] unsupported os');
+    throw Error();
+  }
+}