added Heroku examples with database store

Examples/Program_Heroku.cs

@@ -0,0 +1,147 @@
+using Npgsql;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+using TL;
+
+// This is an example userbot designed to run on a free Heroku account with a free PostgreSQL database for session storage
+// This userbot simply answer "Pong" when someone sends him a "Ping" private message (or in Saved Messages)
+// To use/install/deploy this userbot, follow the steps at the end of this file
+// When run locally, close the window or type ALT-F4 to exit cleanly and save session (similar to Heroku SIGTERM)
+
+namespace WTelegramClientTest
+{
+	static class Program_Heroku
+	{
+		static WTelegram.Client Client;
+		static User My;
+		static readonly Dictionary<long, User> Users = new();
+		static readonly Dictionary<long, ChatBase> Chats = new();
+
+		// See steps at the end of this file to setup required Environment variables
+		static async Task Main(string[] _)
+		{
+			var exit = new SemaphoreSlim(0);
+			AppDomain.CurrentDomain.ProcessExit += (s, e) => exit.Release(); // detect SIGTERM to exit gracefully
+			var store = new PostgreStore(); // if DB does not contain a session, client will be run in interactive mode
+			Client = new WTelegram.Client(store.Length == 0 ? null : Environment.GetEnvironmentVariable, store);
+			using (Client)
+			{
+				Client.Update += Client_Update;
+				My = await Client.LoginUserIfNeeded();
+				Console.WriteLine($"We are logged-in as {My.username ?? My.first_name + " " + My.last_name} (id {My.id})");
+				var dialogs = await Client.Messages_GetAllDialogs();
+				dialogs.CollectUsersChats(Users, Chats);
+				await exit.WaitAsync();
+			}
+		}
+
+		private static async void Client_Update(IObject arg)
+		{
+			if (arg is not UpdatesBase updates) return;
+			updates.CollectUsersChats(Users, Chats);
+			foreach (var update in updates.UpdateList)
+			{
+				Console.WriteLine(update.GetType().Name);
+				if (update is UpdateNewMessage { message: Message { peer_id: PeerUser { user_id: var user_id } } msg }) // private message
+					if (Users.TryGetValue(user_id, out var user))
+					{
+						Console.WriteLine($"New message from {user}: {msg.message}");
+						if (msg.message.Equals("Ping", StringComparison.OrdinalIgnoreCase))
+							await Client.SendMessageAsync(user, "Pong");
+					}
+			}
+		}
+	}
+
+	#region PostgreSQL session store
+	class PostgreStore : Stream
+	{
+		private readonly NpgsqlConnection _sql;
+		private byte[] _data;
+		private int _dataLen;
+		private DateTime _lastWrite;
+		private Task _delayedWrite;
+
+		public PostgreStore()
+		{
+			var parts = Environment.GetEnvironmentVariable("DATABASE_URL").Split(':', '/', '@'); // parse Heroku DB URL
+			_sql = new NpgsqlConnection($"User ID={parts[3]};Password={parts[4]};Host={parts[5]};Port={parts[6]};Database={parts[7]};Pooling=true;SSL Mode=Require;Trust Server Certificate=True;");
+			_sql.Open();
+			using (var create = new NpgsqlCommand($"CREATE TABLE IF NOT EXISTS WTelegram (name text NOT NULL PRIMARY KEY, data bytea)", _sql))
+				create.ExecuteNonQuery();
+			using var cmd = new NpgsqlCommand($"SELECT data FROM WTelegram WHERE name = 'session'", _sql);
+			using var rdr = cmd.ExecuteReader();
+			if (rdr.Read())
+				_dataLen = (_data = rdr[0] as byte[]).Length;
+		}
+
+		protected override void Dispose(bool disposing)
+		{
+			_delayedWrite?.Wait();
+			_sql.Dispose();
+		}
+
+		public override int Read(byte[] buffer, int offset, int count)
+		{
+			Array.Copy(_data, 0, buffer, offset, count);
+			return count;
+		}
+
+		public override void Write(byte[] buffer, int offset, int count) // Write call and buffer modifications are done within a lock()
+		{
+			_data = buffer; _dataLen = count;
+			if (_delayedWrite != null) return;
+			var left = 1000 - (int)(DateTime.UtcNow - _lastWrite).TotalMilliseconds;
+			if (left < 0)
+			{
+				using var cmd = new NpgsqlCommand($"INSERT INTO WTelegram (name, data) VALUES ('session', @data) ON CONFLICT (name) DO UPDATE SET data = EXCLUDED.data", _sql);
+				cmd.Parameters.AddWithValue("data", count == buffer.Length ? buffer : buffer[offset..(offset + count)]);
+				cmd.ExecuteNonQuery();
+				_lastWrite = DateTime.UtcNow;
+			}
+			else // delay writings for a full second
+				_delayedWrite = Task.Delay(left).ContinueWith(t => { lock (this) { _delayedWrite = null; Write(_data, 0, _dataLen); } });
+		}
+
+		public override long Length => _dataLen;
+		public override long Position { get => 0; set { } }
+		public override bool CanSeek => false;
+		public override bool CanRead => true;
+		public override bool CanWrite => true;
+		public override long Seek(long offset, SeekOrigin origin) => 0;
+		public override void SetLength(long value) { }
+		public override void Flush() { }
+	}
+	#endregion
+}
+
+/******************************************************************************************************************************
+HOW TO USE AND DEPLOY THIS EXAMPLE HEROKU USERBOT:
+- From your free Heroku.com account dashboard, create a new app (Free)
+- Navigate to the app Resources and add the add-on "Heroku Postgres" (Hobby Dev - Free)
+- Navigate to the app Settings, click Reveal Config Vars and save the Heroku git URL and the value of DATABASE_URL
+- Add a new var named "api_hash" with your api hash obtained from https://my.telegram.org/apps
+- Add a new var named "phone_number" with the phone_number of the user this userbot will manage
+- Scroll down to Buildpacks and add this URL: https://github.com/jincod/dotnetcore-buildpack.git
+- In Visual Studio, Clone the Heroku git repository and add some standard .gitignore .gitattributes files
+- In this repository folder, create a new .NET Console project with this Program.cs file
+- Add these Nuget packages: WTelegramClient and Npgsql
+- In Project properties > Debug > Environment variables, configure the same values for DATABASE_URL, api_hash, phone_number
+- Run the project in Visual Studio. The first time, it should ask you interactively for elements to complete the connection
+- On the following runs, the PostgreSQL database contains the session data and it should connect automatically
+- You can test the userbot by sending him "Ping" in private message (or saved messages). It should respond with "Pong"
+- You can now commit & push your git sources to Heroku, they will be compiled and deployed/run as a web app
+- The userbot should work fine for 1 minute, but it will be taken down because it is not a web app. Let's fix that
+- Navigate to the app Resources, copy the line starting with: web cd $HOME/.......
+- Back in Visual Studio (or Explorer), at the root of the repository create a Procfile text file (without extension)
+- Paste inside the line you copied, and replace the initial "web" with "worker:" (don't forget the colon)
+- Commit and push the Git changes to Heroku. Wait until the deployment is complete.
+- Verify that the Resources "web" line has changed to "worker" and is enabled (use the pencil icon if necessary)
+- Now your userbot should be running 24/7. Note however that a full month of usage is 31*24 = 744 dyno hours.
+  By default a free account gets 550 free dyno hours per month after which your app is stopped. If you register
+  a credit card with your account, 450 additional free dyno hours are offered at no charge, which should be enough for 24/7
+DISCLAIMER: I'm not affiliated nor expert with Heroku, so if you have any problem with the above I might not be able to help
+******************************************************************************************************************************/

Examples/Program_ListenUpdates.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections.Generic;
-using System.Linq;
 using System.Threading.Tasks;
 using TL;
 
@@ -10,6 +9,8 @@ namespace WTelegramClientTest
 	{
 		static WTelegram.Client Client;
 		static User My;
+		static readonly Dictionary<long, User> Users = new();
+		static readonly Dictionary<long, ChatBase> Chats = new();
 
 		// go to Project Properties > Debug > Environment variables and add at least these: api_id, api_hash, phone_number
 		static async Task Main(string[] _)
@@ -21,27 +22,20 @@ namespace WTelegramClientTest
 			{
 				Client.Update += Client_Update;
 				My = await Client.LoginUserIfNeeded();
-				_users[My.id] = My;
+				Users[My.id] = My;
 				// Note that on login Telegram may sends a bunch of updates/messages that happened in the past and were not acknowledged
 				Console.WriteLine($"We are logged-in as {My.username ?? My.first_name + " " + My.last_name} (id {My.id})");
 				// We collect all infos about the users/chats so that updates can be printed with their names
 				var dialogs = await Client.Messages_GetAllDialogs(); // dialogs = groups/channels/users
-				dialogs.CollectUsersChats(_users, _chats);
+				dialogs.CollectUsersChats(Users, Chats);
 				Console.ReadKey();
 			}
 		}
 
-		private static readonly Dictionary<long, User> _users = new();
-		private static readonly Dictionary<long, ChatBase> _chats = new();
-		private static string User(long id) => _users.TryGetValue(id, out var user) ? user.ToString() : $"User {id}";
-		private static string Chat(long id) => _chats.TryGetValue(id, out var chat) ? chat.ToString() : $"Chat {id}";
-		private static string Peer(Peer peer) => peer is null ? null : peer is PeerUser user ? User(user.user_id)
-			: peer is PeerChat or PeerChannel ? Chat(peer.ID) : $"Peer {peer.ID}";
-
 		private static void Client_Update(IObject arg)
 		{
 			if (arg is not UpdatesBase updates) return;
-			updates.CollectUsersChats(_users, _chats);
+			updates.CollectUsersChats(Users, Chats);
 			foreach (var update in updates.UpdateList)
 				switch (update)
 				{
@@ -69,5 +63,10 @@ namespace WTelegramClientTest
 				case MessageService ms: Console.WriteLine($"{Peer(ms.from_id)} in {Peer(ms.peer_id)} [{ms.action.GetType().Name[13..]}]"); break;
 			}
 		}
+
+		private static string User(long id) => Users.TryGetValue(id, out var user) ? user.ToString() : $"User {id}";
+		private static string Chat(long id) => Chats.TryGetValue(id, out var chat) ? chat.ToString() : $"Chat {id}";
+		private static string Peer(Peer peer) => peer is null ? null : peer is PeerUser user ? User(user.user_id)
+			: peer is PeerChat or PeerChannel ? Chat(peer.ID) : $"Peer {peer.ID}";
 	}
 }