🚧 CAS integration

modules/CombotAntiSpam/Combot/CombotApiResponse.cs

@@ -0,0 +1,31 @@
+using System;
+using Newtonsoft.Json;
+
+namespace Kruzya.TelegramBot.CombotAntiSpam.Combot
+{
+    internal class CombotApiResponse
+    {
+        public class ApiResult
+        {
+            [JsonProperty("messages")]
+            public string[] Messages { get; set; }
+            
+            [JsonProperty("time_added")]
+            public int TimeAdded { get; set; }
+            
+            [JsonProperty("offenses")]
+            public int Offenses { get; set; }
+
+            public DateTime AddedAt => DateTimeOffset.FromUnixTimeSeconds(TimeAdded).DateTime;
+        }
+
+        [JsonProperty("ok")]
+        public bool IsSpammer { get; set; }
+        
+        [JsonProperty("description")]
+        public string Description { get; set; }
+        
+        [JsonProperty("result")]
+        public ApiResult Result { get; set; }
+    }
+}

modules/CombotAntiSpam/Combot/CombotClient.cs

@@ -0,0 +1,30 @@
+using System;
+using System.Net.Http;
+using System.Threading.Tasks;
+using Kruzya.TelegramBot.Core.Extensions;
+using Telegram.Bot.Types;
+
+namespace Kruzya.TelegramBot.CombotAntiSpam.Combot
+{
+    public class CombotClient : ICombotClient
+    {
+        public HttpClient _HttpClient;
+
+        public CombotClient()
+        {
+            _HttpClient = new HttpClient();
+            _HttpClient.BaseAddress = new Uri("https://api.cas.chat/check");
+        }
+        
+        public bool IsSpammer(User user)
+        {
+            return IsSpammerAsync(user).GetAwaiter().GetResult();
+        }
+
+        public async Task<bool> IsSpammerAsync(User user)
+        {
+            var result = await _HttpClient.GetJsonAsync<CombotApiResponse>($"?user_id={user.Id}");
+            return result.IsSpammer;
+        }
+    }
+}

modules/CombotAntiSpam/Combot/ICombotClient.cs

@@ -0,0 +1,11 @@
+using System.Threading.Tasks;
+using Telegram.Bot.Types;
+
+namespace Kruzya.TelegramBot.CombotAntiSpam.Combot
+{
+    public interface ICombotClient
+    {
+        public bool IsSpammer(User user);
+        public Task<bool> IsSpammerAsync(User user);
+    }
+}

modules/CombotAntiSpam/CombotAntiSpam.csproj

@@ -0,0 +1,13 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>netcoreapp3.1</TargetFramework>
+        <AssemblyName>TelegramBot.CombotAntiSpam</AssemblyName>
+        <RootNamespace>Kruzya.TelegramBot.CombotAntiSpam</RootNamespace>
+    </PropertyGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\..\Core\Core.csproj" />
+    </ItemGroup>
+
+</Project>

modules/CombotAntiSpam/Startup.cs

@@ -0,0 +1,18 @@
+using Kruzya.TelegramBot.CombotAntiSpam.Combot;
+using Kruzya.TelegramBot.Core;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace Kruzya.TelegramBot.CombotAntiSpam
+{
+    public class Startup : Module
+    {
+        public Startup(Core.Core core) : base(core)
+        {
+        }
+
+        public override void ConfigureServices(IServiceCollection services)
+        {
+            services.AddSingleton<ICombotClient, CombotClient>();
+        }
+    }
+}

modules/CombotAntiSpam/UserJoinHandler.cs

@@ -0,0 +1,50 @@
+using System.Text;
+using System.Threading.Tasks;
+using BotFramework;
+using BotFramework.Attributes;
+using BotFramework.Setup;
+using Kruzya.TelegramBot.CombotAntiSpam.Combot;
+using Kruzya.TelegramBot.Core.Extensions;
+using Microsoft.Extensions.Logging;
+using Telegram.Bot.Types.Enums;
+
+namespace Kruzya.TelegramBot.CombotAntiSpam
+{
+    public class UserJoinHandler : BotEventHandler
+    {
+        protected ICombotClient _combotClient;
+        protected ILogger _logger;
+
+        public UserJoinHandler(ICombotClient combotClient)
+        {
+            _combotClient = combotClient;
+        }
+
+        [Message(MessageType.ChatMembersAdded, InChat.Public)]
+        public async Task OnUserJoined()
+        {
+            var canKickMembers = ((await Bot.GetChatMemberAsync(Chat, (await Bot.GetMeAsync()).Id)).CanRestrictMembers == true);
+
+            foreach (var member in RawUpdate.Message.NewChatMembers)
+            {
+                if (!(await _combotClient.IsSpammerAsync(member)))
+                {
+                    continue;
+                }
+                
+                var messageText = new StringBuilder();
+                messageText.Append($"⚠️ <b>Combot Anti-Spam</b>\n\n");
+                messageText.Append($"User {member.ToHtml()} is spammer.\n");
+                messageText.Append(
+                    $"More details you can find on <a href=\"https://cas.chat/query?u={member.Id}\">CAS site</a>.");
+                
+                await Bot.SendTextMessageAsync(Chat, messageText.ToString(), ParseMode.Html);
+                
+                if (canKickMembers)
+                {
+                    await Bot.KickChatMemberAsync(Chat, member.Id);
+                }
+            }
+        }
+    }
+}