/// <summary>
/// Passes an update to the chain for handling
/// </summary>
/// <param name="args">Data structure containing relevant references for update handling</param>
public async Task Handle(UpdateHandlerArgs args)
{
// Catch exceptions so they don't cause the entire service to crash
try
{
if ((null == HandlesUpdateType) || (args.Update.Type == HandlesUpdateType))
{
await HandlerLogicImpl(args);
}
}
catch (Exception e)
{
await Say.Error($"Internal error while handling update {args.Update.Id}: {e.Message}");
}
// End of the chain has reached as soon as the update has been marked as handled
if (args.Handled)
{
return;
}
// Invoke next handler in chain, otherwise throw Exception that update was not handled
if (null != _nextHandler)
{
await _nextHandler.Handle(args);
}
else
{
throw new UpdateNotHandledException(args.Update);
}
}
static async Task Main(string[] args)
{
// ------------------------------------------------------------------------------------
// Step 1: Verify and/ or set up environement
if (String.IsNullOrWhiteSpace(Environment.GetEnvironmentVariable("BOT_TOKEN")))
{
// Environment.SetEnvironmentVariable("BOT_TOKEN", "");
await Say.Error("Fatal: Environment Variable BOT_TOKEN empty");
return;
}
// ------------------------------------------------------------------------------------
// Step 2 - Setting up the bot object
_UpdateHandlerChain = new DevHandler();
_UpdateHandlerChain.Add(new StartHandler());
_Bot = new TelegramBotClient(Environment.GetEnvironmentVariable("BOT_TOKEN"));
_BotUpdatesChannel = Channel.CreateUnbounded <Update>(
new UnboundedChannelOptions()
{
SingleWriter = true,
SingleReader = true
});
var updateHandler = Task.Run(async() => await _HandleUpdates());
var updateFetcher = Task.Run(async() => await _FetchUpdates(_CancelWorkerTasks.Token));
// Setting up Event Handler for Smooth Termination ( Improved Thread.Sleep(forever) )
Console.CancelKeyPress += async(object sender, ConsoleCancelEventArgs e) =>
{
e.Cancel = true; // Intercept the CTRL+C
_TerminateProcessEvent.Set(); // Signal the main thread
await Say.Warning("Cancellation request sent");
};
_TerminateProcessEvent.WaitOne(); // Suspend main thread until signaled
// ------------------------------------------------------------------------------------
// Step 3 - Tidy up: Release ressources, flush buffers, etc
_CancelWorkerTasks.Cancel();
await Task.WhenAll(updateFetcher, updateHandler);
await Say.Success("Thank you very much. You made a simple bot very happy");
}
