GitLab search (#422) + better settings UI

lib/app_sources/gitlab.dart

@@ -1,15 +1,47 @@
+import 'dart:convert';
+
+import 'package:flutter/material.dart';
 import 'package:html/parser.dart';
 import 'package:http/http.dart';
 import 'package:obtainium/app_sources/github.dart';
 import 'package:obtainium/custom_errors.dart';
+import 'package:obtainium/providers/settings_provider.dart';
 import 'package:obtainium/providers/source_provider.dart';
 import 'package:obtainium/components/generated_form.dart';
 import 'package:easy_localization/easy_localization.dart';
+import 'package:url_launcher/url_launcher_string.dart';
 
 class GitLab extends AppSource {
   GitLab() {
     host = 'gitlab.com';
     overrideEligible = true;
+    canSearch = true;
+
+    additionalSourceSpecificSettingFormItems = [
+      GeneratedFormTextField('gitlab-creds',
+          label: tr('gitlabPATLabel'),
+          password: true,
+          required: false,
+          belowWidgets: [
+            const SizedBox(
+              height: 4,
+            ),
+            GestureDetector(
+                onTap: () {
+                  launchUrlString(
+                      'https://docs.gitlab.com/ee/user/profile/personal_access_tokens.html#create-a-personal-access-token',
+                      mode: LaunchMode.externalApplication);
+                },
+                child: Text(
+                  tr('about'),
+                  style: const TextStyle(
+                      decoration: TextDecoration.underline, fontSize: 12),
+                )),
+            const SizedBox(
+              height: 4,
+            )
+          ])
+    ];
 
     additionalSourceAppSpecificSettingFormItems = [
       [
@@ -29,6 +61,37 @@ class GitLab extends AppSource {
     return url.substring(0, match.end);
   }
 
+  Future<String?> getPATIfAny() async {
+    SettingsProvider settingsProvider = SettingsProvider();
+    await settingsProvider.initializeSettings();
+    String? creds = settingsProvider
+        .getSettingString(additionalSourceSpecificSettingFormItems[0].key);
+    return creds != null && creds.isNotEmpty ? creds : null;
+  }
+
+  @override
+  Future<Map<String, List<String>>> search(String query) async {
+    String? PAT = await getPATIfAny();
+    if (PAT == null) {
+      throw CredsNeededError(name);
+    }
+    var url =
+        'https://$host/api/v4/search?private_token=$PAT&scope=projects&search=${Uri.encodeQueryComponent(query)}';
+    var res = await sourceRequest(url);
+    if (res.statusCode != 200) {
+      throw getObtainiumHttpError(res);
+    }
+    var json = jsonDecode(res.body) as List<dynamic>;
+    Map<String, List<String>> results = {};
+    json.forEach((element) {
+      results['https://$host/${element['path_with_namespace']}'] = [
+        element['name_with_namespace'],
+        element['description'] ?? tr('noDescription')
+      ];
+    });
+    return results;
+  }
+
   @override
   String? changeLogPageFromStandardUrl(String standardUrl) =>
       '$standardUrl/-/releases';