new: add link parser and allow custom configs to be imported

lib/features/profile/data/profile_repository.dart

@@ -361,7 +361,7 @@ class ProfileRepositoryImpl
     );
   }
 
-  final _subInfoHeaders = [
+  static final  _subInfoHeaders = [
     'profile-title',
     'content-disposition',
     'subscription-userinfo',
@@ -418,8 +418,20 @@ class ProfileRepositoryImpl
       "only [$headersFound] headers found, checking file content for possible information",
     );
     var content = await File(path).readAsString();
-    content = safeDecodeBase64(content);
-    final lines = content.split("\n");
+    final contentHeaders = parseHeadersFromContent(content);
+    for (final entry in contentHeaders.entries) {
+      if (!headers.keys.contains(entry.key) && entry.value.isNotEmpty) {
+        headers[entry.key] = entry.value;
+      }  
+    }
+    
+    return headers;
+  }
+
+  static Map<String, List<String>> parseHeadersFromContent(String content) {
+    final headers = <String, List<String>>{};
+    final content_ = safeDecodeBase64(content);
+    final lines = content_.split("\n");
     final linesToProcess = lines.length < 10 ? lines.length : 10;
     for (int i = 0; i < linesToProcess; i++) {
       final line = lines[i];

lib/utils/link_parsers.dart

@@ -1,5 +1,8 @@
 import 'dart:convert';
 
+import 'package:dartx/dartx.dart';
+import 'package:hiddify/features/profile/data/profile_parser.dart';
+import 'package:hiddify/features/profile/data/profile_repository.dart';
 import 'package:hiddify/singbox/model/singbox_proxy_type.dart';
 import 'package:hiddify/utils/validators.dart';
 
@@ -19,13 +22,11 @@ abstract class LinkParser {
     );
     // return 'hiddify://import/$modifiedUri';
     return '$modifiedUri';
-
   }
 
   // protocols schemas
   static const protocols = {'clash', 'clashmeta', 'sing-box', 'hiddify'};
 
-
   static ProfileLink? parse(String link) {
     return simple(link) ?? deep(link);
   }
@@ -40,13 +41,16 @@ abstract class LinkParser {
   }
 
   static ({String content, String name})? protocol(String content) {
-    final lines = safeDecodeBase64(content).split('\n');
+    final normalContent = safeDecodeBase64(content);
+    final lines = normalContent.split('\n');
+    String? name;
     for (final line in lines) {
       final uri = Uri.tryParse(line);
       if (uri == null) continue;
       final fragment =
           uri.hasFragment ? Uri.decodeComponent(uri.fragment) : null;
-      final name = switch (uri.scheme) {
+      if (name != null) {
+        name = switch (uri.scheme) {
           'ss' => fragment ?? ProxyType.shadowsocks.label,
           'ssconf' => fragment ?? ProxyType.shadowsocks.label,
           'vmess' => ProxyType.vmess.label,
@@ -58,13 +62,18 @@ abstract class LinkParser {
           'ssh' => fragment ?? ProxyType.ssh.label,
           'wg' => fragment ?? ProxyType.wireguard.label,
           'warp' => fragment ?? ProxyType.warp.label,
-        _ => ProxyType.unknown.label,
+          _ => null,
         };
-      if (name != null) {
-        return (content: content, name: name);
       }
     }
-    return null;
+    final headers = ProfileRepositoryImpl.parseHeadersFromContent(content);
+    final subinfo = ProfileParser.parse("", headers);
+
+    if (subinfo.name.isNotNullOrEmpty) {
+      name = subinfo.name;
+    }
+
+    return (content: normalContent, name: name ?? ProxyType.unknown.label);
   }
 
   static ProfileLink? deep(String link) {
@@ -82,7 +91,10 @@ abstract class LinkParser {
         return (url: queryParams['url']!, name: queryParams['name'] ?? '');
       case 'hiddify':
         if (uri.authority == "import") {
-        return (url: uri.path.substring(1)+(uri.hasQuery?"?${uri.query}":""), name: uri.fragment);
+          return (
+            url: uri.path.substring(1) + (uri.hasQuery ? "?${uri.query}" : ""),
+            name: uri.fragment
+          );
         }
         //for backward compatibility
         if ((uri.authority != 'install-config' &&