feat: InternalDNS switch

lib/common/io/doh_client.dart

@@ -0,0 +1,46 @@
+import 'dart:convert';
+
+import 'package:starcitizen_doctor/common/conf/const_conf.dart';
+import 'package:starcitizen_doctor/common/io/rs_http.dart';
+import 'package:starcitizen_doctor/common/utils/log.dart';
+import 'package:starcitizen_doctor/data/doh_client_response_data.dart';
+
+class DohClient {
+  static Future<DohClientResponseData?> resolve(
+      String domain, String type) async {
+    try {
+      final r = await RSHttp.getText(
+          "${ConstConf.dohAddress}?name=$domain&type=$type");
+      final data = DohClientResponseData.fromJson(json.decode(r));
+      return data;
+    } catch (e) {
+      dPrint("DohClient.resolve error: $e");
+      return null;
+    }
+  }
+
+  static Future<List<String>?> resolveIP(String domain, String type) async {
+    final data = await resolve(domain, type);
+    if (data == null) return [];
+    return data.answer?.map((e) => _removeDataPadding(e.data)).toList();
+  }
+
+  static Future<List<String>?> resolveTXT(String domain) async {
+    final data = await resolve(domain, "TXT");
+    if (data == null) return [];
+    return data.answer?.map((e) => _removeDataPadding(e.data)).toList();
+  }
+
+  static String _removeDataPadding(String? data) {
+    // data demo: {"data":"\"https://git.scbox.xkeyc.cn,https://gitapi.scbox.org\""}
+    if (data == null) return "";
+    data = data.trim();
+    if (data.startsWith("\"")){
+      data = data.substring(1);
+    }
+    if (data.endsWith("\"")){
+      data = data.substring(0, data.length - 1);
+    }
+    return data;
+  }
+}