Overseer and HttpsMessageBuilder

Telegram/HtmlMessageBuilder.cs

@@ -0,0 +1,182 @@
+
+using System.Net.Mime;
+using Microsoft.Extensions.Primitives;
+
+namespace InstaFollowersOverseer;
+
+/// <summary>
+/// Class that builds selegram message with html tags.
+/// It is a state machine.
+/// Exapmple:
+///  SetUrl("https://x.com").BeginStyle(TextStyle.Url).Text("X").EndStyle()
+///  opens html a tag with href=https://x.com and content X, then closes tag
+/// </summary>
+// supported tags:
+// <b>bold</b>
+// <i>italic</i> 
+// <s>crossed</s>
+// <u>underline</u>
+// <tg-spoiler>spoiler</tg-spoiler>
+// <a href="http://www.example.com/">inline URL</a>
+// <a href="tg://user?id=123456789">inline mention of a user</a>
+// <code>inlne code</code>
+// <pre language="c++">code block</pre>
+public class HtmlMessageBuilder
+{
+    record struct BuilderState(TextStyle Style, string? Url = null, long? UserId = null, string? CodeLang = null)
+    {
+        public void Reset()
+        {
+            Style = TextStyle.PlainText;
+            Url = null;
+            UserId = null;
+            CodeLang = null;
+        }
+    }
+
+    private BuilderState _state=new(TextStyle.PlainText);
+    StringBuilder _plainText=new();
+    StringBuilder _html=new();
+
+    protected void ReplaceHtmlReservedChar(char c) =>
+        _html.Append(c switch
+        {
+            '<'=>"&lt",
+            '>'=>"&gt",
+            '&'=>"&apm",
+            '"'=>"&quot",
+            '\''=>"&apos",
+            _ => c
+        });
+    
+    protected void ReplaceHtmlReservedChars(ReadOnlySpan<char> text)
+    {
+        for (int i = 0; i < text.Length; i++) 
+            ReplaceHtmlReservedChar(text[i]);
+    }
+
+    /// opens html tags enabled in state fields
+    protected void OpenTags()
+    {
+        if(_state.Style==TextStyle.PlainText)
+            return;
+        
+        // the order of fields is very importang, it must be in reversed in CloseTags()
+        if (0!=(_state.Style & TextStyle.Bold))  _html.Append("<b>");
+        if (0!=(_state.Style & TextStyle.Italic)) _html.Append("<i>");
+        if (0!=(_state.Style & TextStyle.Crossed))  _html.Append("<s>");
+        if (0!=(_state.Style & TextStyle.Underline)) _html.Append("<u>");
+        if (0!=(_state.Style & TextStyle.Spoiler)) _html.Append("<tg-spoiler>");
+        if (0!=(_state.Style & TextStyle.Link))
+        {
+            _html.Append("<a href='");
+            if (_state.UserId is not null)
+                _html.Append("tg://user?id=").Append(_state.UserId);
+            else if (!_state.Url.IsNullOrEmpty()) 
+                _html.Append(_state.Url);
+            else throw new Exception("empty url");
+            _html.Append("'>");
+        }
+        if (0!=(_state.Style & TextStyle.CodeLine)) _html.Append("<code>");
+        if (0!=(_state.Style & TextStyle.CodeBlock)) 
+        { 
+            _html.Append("<pre");
+            if (!_state.CodeLang.IsNullOrEmpty())
+                _html.Append(" language='").Append(_state.CodeLang).Append('\'');
+            _html.Append('>');
+        }
+    }
+
+    /// closes opened html tags 
+    protected void CloseTags()
+    {
+        if(_state.Style==TextStyle.PlainText)
+            return;
+        
+        // the order of fields is very importang, it must be in reversed in CloseTags()
+        if (0!=(_state.Style & TextStyle.CodeBlock)) _html.Append("</pre>");
+        if (0!=(_state.Style & TextStyle.CodeLine))  _html.Append("</code>");
+        if (0!=(_state.Style & TextStyle.Link))      _html.Append("</a>");
+        if (0!=(_state.Style & TextStyle.Spoiler))   _html.Append("</tg-spoiler>");
+        if (0!=(_state.Style & TextStyle.Underline)) _html.Append("</u>");
+        if (0!=(_state.Style & TextStyle.Crossed))   _html.Append("</s>");
+        if (0!=(_state.Style & TextStyle.Italic))    _html.Append("</i>");
+        if (0!=(_state.Style & TextStyle.Bold))      _html.Append("</b>");
+        _state.Reset();
+    }
+
+    /// appends text to builder
+    public HtmlMessageBuilder Text(string text)
+    {
+        _plainText.Append(text);
+        ReplaceHtmlReservedChars(text);
+        return this;
+    }
+    public HtmlMessageBuilder Text(char ch)
+    {
+        _plainText.Append(ch);
+        ReplaceHtmlReservedChar(ch);
+        return this;
+    }
+    public HtmlMessageBuilder Text(int o)
+    {
+        string text = o.ToString();
+        _plainText.Append(text);
+        ReplaceHtmlReservedChars(text);
+        return this;
+    }
+    public HtmlMessageBuilder Text(long o)
+    {
+        string text = o.ToString();
+        _plainText.Append(text);
+        ReplaceHtmlReservedChars(text);
+        return this;
+    }
+    public HtmlMessageBuilder Text(object o)
+    {
+        if (o is null)
+            throw new NullReferenceException("object is null");
+        string text = o.ToString()!;
+        _plainText.Append(text);
+        ReplaceHtmlReservedChars(text);
+        return this;
+    }
+    
+    /// enables specified styles
+    public HtmlMessageBuilder BeginStyle(TextStyle style)
+    {
+        if (_state.Style != TextStyle.PlainText)
+            throw new Exception("can't begin new style before ending previous");
+        _state.Style = style;
+        OpenTags();
+        return this;
+    }
+
+    /// removes all styles
+    public HtmlMessageBuilder EndStyle()
+    {
+        CloseTags();
+        return this;
+    }
+    
+    // use before BeginStyle
+    public HtmlMessageBuilder SetUrl(string url) { _state.Url = url; return this; }
+    public HtmlMessageBuilder SetUserMention(long id) { _state.UserId=id ; return this; }
+    public HtmlMessageBuilder SetCodeLanguage(string codeLang="") { _state.CodeLang=codeLang ; return this; }
+    
+    public string ToPlainText() => _plainText.ToString();
+    public string ToHtml() => _html.ToString();
+    
+    #if DEBUG
+    public override string ToString() => ToHtml();
+    #else
+    public override string ToString() => ToPlainText();
+    #endif
+
+    public void Clear()
+    {
+        _plainText.Clear();
+        _html.Clear();
+        _state.Reset();
+    }
+}

Telegram/Overseer.cs

@@ -0,0 +1,81 @@
+using InstaFollowersOverseer.Instagram;
+
+namespace InstaFollowersOverseer;
+
+public static class Overseer
+{
+    private static ContextLogger ObserverLogger = new("observer",ParentLogger);
+
+    private static CancellationTokenSource OverseeCancel = new();
+
+    public static async void Start()
+    {
+        try
+        {
+            ObserverLogger.LogInfo("observer is starting");
+            while (!OverseeCancel.Token.IsCancellationRequested)
+            {
+                ObserverLogger.LogDebug("loop begins");
+                // parallel diff computation per telegram user
+                Parallel.ForEach(CurrentUsersData.UsersDict,
+                     tgUserData => 
+                {
+                    try
+                    {
+                        var instaUsers = tgUserData.Value;
+                        long chatId = tgUserData.Key.ToLong();
+                        
+                        // parallel diff computation per instagram user
+                        Parallel.For(0, instaUsers.Count, DiffInstaUser);
+                        
+                        async void DiffInstaUser(int i)
+                        {
+                            try
+                            {
+                                HtmlMessageBuilder b = new();
+                                ObserverLogger.LogInfo($"comparing followers lists of user {instaUsers[i]}");
+                                // slow operation
+                                FollowersDiff diff =
+                                    await InstagramWrapper.GetFollowersDiffAsync(instaUsers[i].instagramUsername);
+                                
+                                b.BeginStyle(TextStyle.Bold | TextStyle.Underline)
+                                    .Text(instaUsers[i].instagramUsername)
+                                    .EndStyle()
+                                    .Text('\n');
+                                diff.AppendDiffMessageTo(b, OverseeCancel.Token);
+                                ObserverLogger.LogInfo($"sending notification to {tgUserData.Key}");
+                                await TelegramWrapper.SendInfo(chatId, b);
+                            }
+                            catch(OperationCanceledException){}
+                            catch (Exception ex)
+                            {
+                                ObserverLogger.LogWarn("ObserveLoop", ex);
+                            }
+                        }
+
+                    }
+                    catch (OperationCanceledException) {}
+                    catch (Exception ex)
+                    {
+                        ObserverLogger.LogWarn("ObserveLoop", ex);
+                    }
+                });
+
+                ObserverLogger.LogDebug("loop ends");
+                await Task.Delay(TimeSpan.FromMinutes(CurrentConfig.checksIntervalMinutes));
+            }
+        }
+        catch (OperationCanceledException) {}
+        catch (Exception ex)
+        {
+            ObserverLogger.LogError("ObserveLoop", ex);
+        }
+    }
+
+    public static void Stop()
+    {
+        ObserverLogger.LogInfo("observer is stopping");
+        OverseeCancel.Cancel();
+        OverseeCancel = new CancellationTokenSource();
+    }
+}

Telegram/TelegramWrapper.cs

@@ -1,19 +1,18 @@
 using System.Net.Http;
-using System.Threading;
 using Telegram.Bot;
 using Telegram.Bot.Polling;
 using Telegram.Bot.Types;
 using Telegram.Bot.Types.Enums;
 using InstaFollowersOverseer.Instagram;
 
-namespace InstaFollowersOverseer.Telegram;
+namespace InstaFollowersOverseer;
 
 public static class TelegramWrapper
 {
     private static ContextLogger TelegramLogger = new("telegram", ParentLogger);
     private static TelegramBotClient Bot=null!;
 
-    public static async void Init()
+    public static async Task InitAsync()
     {
         try
         {
@@ -35,7 +34,7 @@ public static class TelegramWrapper
             };
             TelegramLogger.LogInfo("bot starting recieving long polls");
             Bot.StartReceiving(BotApiUpdateHandler, BotApiExceptionHandler, receiverOptions, Program.MainCancelToken);
-            TelegramLogger.LogInfo("telegram wrapper have initialized successfully");
+            TelegramLogger.LogInfo("telegram wrapper initialized successfully");
         }
         catch (OperationCanceledException) {}
         catch (Exception ex)
@@ -50,20 +49,34 @@ public static class TelegramWrapper
         TelegramLogger.LogError(ex);
         return Task.CompletedTask;
     }
-
-    static async Task SendInfoReply(string text, Message replyToMessage)
+    
+    /// parses text from markdown to html and sends to telegram chat
+    public static async Task SendMessage(ChatId chatId, HtmlMessageBuilder message, int? replyToMesId=null)
     {
-        TelegramLogger.LogInfo(text);
-        await Bot.SendTextMessageAsync(replyToMessage.Chat, text, 
-            replyToMessageId: replyToMessage.MessageId, 
-            parseMode:ParseMode.MarkdownV2);
+        string html = message.ToHtml();
+        await Bot.SendTextMessageAsync(chatId, html,
+            replyToMessageId: replyToMesId,
+            parseMode: ParseMode.Html);
+        message.Clear();
     }
-    static async Task SendErrorReply(string text, Message replyToMessage)
+
+    public static async Task SendInfo(ChatId chatId, HtmlMessageBuilder message, int? replyToMesId=null)
     {
-        TelegramLogger.LogWarn(text);
-        await Bot.SendTextMessageAsync(replyToMessage.Chat, "error: "+text, 
-            replyToMessageId: replyToMessage.MessageId, 
-            parseMode:ParseMode.MarkdownV2);
+        TelegramLogger.LogInfo(message);
+        await SendMessage(chatId, message, replyToMesId);
+    }
+    
+    public static async Task SendError(ChatId chatId, HtmlMessageBuilder message, int? replyToMesId=null)
+    {
+        TelegramLogger.LogWarn(message);
+        await SendMessage(chatId, new HtmlMessageBuilder().BeginStyle(TextStyle.Bold | TextStyle.Italic)
+            .Text("error: ").EndStyle().Text(message), replyToMesId);
+    }
+    public static async Task SendError(ChatId chatId, Exception ex, int? replyToMesId=null)
+    {
+        TelegramLogger.LogWarn(ex);
+        await SendMessage(chatId, new HtmlMessageBuilder().BeginStyle(TextStyle.Bold | TextStyle.Italic)
+            .Text("error: ").EndStyle().Text(ex.Message), replyToMesId);
     }
     
     private static async Task BotApiUpdateHandler(ITelegramBotClient bot, Update update, CancellationToken cls)
@@ -107,28 +120,66 @@ public static class TelegramWrapper
 
     private static async Task ExecCommandAsync(string command, string[] args, Message message)
     {
-        switch (command)
+        try
         {
-            case "start":
-                await Bot.SendTextMessageAsync(message.Chat, "hi");
-                break;
-            case "oversee":
+            HtmlMessageBuilder rb = new();
+            long senderId = message.From?.Id ?? message.Chat.Id;
+            string senderName = message.From?.FirstName ?? message.Chat.FirstName ??
+                message.Chat.Username ?? "UnknownUser";
+            switch (command)
             {
-                string usernameOrUrl = args[0];
-                await SendInfoReply($"searching for instagram user <{usernameOrUrl}>", message);
-                var user = await InstagramWrapper.GetUserAsync(usernameOrUrl);
-                if (user is null)
+                case "start":
+                    await SendInfo(message.Chat, rb.Text("bot started"));
+                    break;
+                case "oversee":
                 {
-                    await SendErrorReply($"user **{usernameOrUrl}** doesnt exist", message);
-                    return;
+                    string usernameOrUrl = args[0];
+                    await SendInfo(message.Chat, rb.Text("searching for instagram user"), message.MessageId);
+                    var user = await InstagramWrapper.TryGetUserAsync(usernameOrUrl);
+                    if (user is null)
+                    {
+                        await SendError(message.Chat, rb.Text("user ").Text(usernameOrUrl).Text(" not found"));
+                        return;
+                    }
+                    await SendInfo(message.Chat, rb.Text("user ").Text(usernameOrUrl).Text(" found"));
+                    // user id or chat id
+                    CurrentUsersData.AddOrSet(senderId, new InstagramObservableParams(usernameOrUrl));
+                    CurrentUsersData.SaveToFile();
+                    break;
                 }
-                CurrentUsersData.AddOrSet(message.Chat.Id.ToString(), new InstagramObservableParams(usernameOrUrl));
-                CurrentUsersData.SaveToFile();
-                break;
+                case "list":
+                {
+                    var userData = CurrentUsersData.Get(senderId);
+                    if (userData is null)
+                    {
+                        await SendError(message.Chat, rb.Text("no data for user"), message.MessageId);
+                        return;
+                    }
+
+                    rb.Text(userData.Count).Text("instagram users:\n");
+                    foreach (var iuParams in userData)
+                    {
+                        rb.BeginStyle(TextStyle.Bold).Text(iuParams.instagramUsername).EndStyle().Text(" - ");
+                        var iu = await InstagramWrapper.TryGetUserAsync(iuParams.instagramUsername);
+                        rb.Text(iu is null ? "user no longer exists" : iu.FullName);
+                        rb.SetUrl("https://www.instagram.com/"+iuParams.instagramUsername)
+                            .BeginStyle(TextStyle.Link)
+                            .Text(iuParams.instagramUsername)
+                            .EndStyle().Text('\n');
+                    }
+
+                    await SendInfo(message.Chat, rb, message.MessageId);
+                    break;
+                }
+                default:
+                    await SendError(message.Chat, rb.Text("ivalid command"), message.MessageId);
+                    break;
             }
-            default:
-                await SendErrorReply("ivalid command", message);
-                break;
+        }
+        catch(OperationCanceledException){}
+        catch (Exception ex)
+        {
+            await SendError(message.Chat, ex);
         }
     }
 }

Telegram/TextStyle.cs

@@ -0,0 +1,9 @@
+namespace InstaFollowersOverseer;
+
+[Flags]
+public enum TextStyle
+{
+    PlainText=0,
+    Bold=1, Italic=2, Crossed=4, Underline=8,
+    Spoiler=16, Link=32, CodeLine=64, CodeBlock=128
+}