implemented full interactive poll support in Talk, including creation, voting, and closing functionality

lib/api/marianumcloud/talk/create_poll/create_poll.dart

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+import 'dart:convert';
+
+import 'package:http/http.dart' as http;
+
+import '../../../api_params.dart';
+import '../talk_api.dart';
+import 'create_poll_params.dart';
+
+/// Erstellt eine Umfrage; der Server postet die Poll-Nachricht selbst in den
+/// Chat, danach genügt ein Chat-Refresh. Nur in Gruppen-Chats erlaubt.
+class CreatePoll extends TalkApi {
+  CreatePoll({required String token, required CreatePollParams params})
+    : super(
+        'v1/poll/$token',
+        params,
+        headers: {'Content-Type': 'application/json'},
+      );
+
+  @override
+  Null assemble(String raw) => null;
+
+  @override
+  Future<http.Response>? request(
+    Uri uri,
+    ApiParams? body,
+    Map<String, String>? headers,
+  ) {
+    if (body is! CreatePollParams) return null;
+    return http.post(uri, headers: headers, body: jsonEncode(body.toJson()));
+  }
+}

lib/api/marianumcloud/talk/create_poll/create_poll_params.dart

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+import 'package:json_annotation/json_annotation.dart';
+
+import '../../../api_params.dart';
+
+part 'create_poll_params.g.dart';
+
+@JsonSerializable()
+class CreatePollParams extends ApiParams {
+  String question;
+  List<String> options;
+
+  /// 0 = Ergebnisse öffentlich, 1 = bis zum Schließen verborgen.
+  int resultMode;
+
+  /// Stimmen pro Teilnehmer; 0 = unbegrenzt.
+  int maxVotes;
+
+  CreatePollParams({
+    required this.question,
+    required this.options,
+    required this.resultMode,
+    required this.maxVotes,
+  });
+  factory CreatePollParams.fromJson(Map<String, dynamic> json) =>
+      _$CreatePollParamsFromJson(json);
+  Map<String, dynamic> toJson() => _$CreatePollParamsToJson(this);
+}

lib/api/marianumcloud/talk/create_poll/create_poll_params.g.dart

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+// GENERATED CODE - DO NOT MODIFY BY HAND
+
+part of 'create_poll_params.dart';
+
+// **************************************************************************
+// JsonSerializableGenerator
+// **************************************************************************
+
+CreatePollParams _$CreatePollParamsFromJson(Map<String, dynamic> json) =>
+    CreatePollParams(
+      question: json['question'] as String,
+      options: (json['options'] as List<dynamic>)
+          .map((e) => e as String)
+          .toList(),
+      resultMode: (json['resultMode'] as num).toInt(),
+      maxVotes: (json['maxVotes'] as num).toInt(),
+    );
+
+Map<String, dynamic> _$CreatePollParamsToJson(CreatePollParams instance) =>
+    <String, dynamic>{
+      'question': instance.question,
+      'options': instance.options,
+      'resultMode': instance.resultMode,
+      'maxVotes': instance.maxVotes,
+    };