private async Task UpdateActivityInternal(Activity activity,
IEnumerable <UpdateActivityHandler> updateHandlers,
Func <Task> callAtBottom)
{
BotAssertSlack.ActivityNotNull(activity);
if (updateHandlers == null)
{
throw new ArgumentException(nameof(updateHandlers));
}
if (updateHandlers.Count() == 0) // No middleware to run.
{
if (callAtBottom != null)
{
await callAtBottom();
}
return;
}
// Default to "No more Middleware after this".
async Task next()
{
// Remove the first item from the list of middleware to call,
// so that the next call just has the remaining items to worry about.
IEnumerable <UpdateActivityHandler> remaining = updateHandlers.Skip(1);
await UpdateActivityInternal(activity, remaining, callAtBottom).ConfigureAwait(false);
}
// Grab the current middleware, which is the 1st element in the array, and execute it
UpdateActivityHandler toCall = updateHandlers.First();
await toCall(this, activity, next);
}
/// <summary>
/// Creates a conversation reference from an activity.
/// </summary>
/// <param name="activity">The activity.</param>
/// <returns>A conversation reference for the conversation that contains the activity.</returns>
/// <exception cref="ArgumentNullException">
/// <paramref name="activity"/> is <c>null</c>.</exception>
public static ConversationReference GetConversationReference(Activity activity)
{
BotAssertSlack.ActivityNotNull(activity);
ConversationReference r = new ConversationReference
{
ActivityId = activity.Id,
User = activity.From,
Bot = activity.Recipient,
Conversation = activity.Conversation,
ChannelId = activity.ChannelId,
ServiceUrl = activity.ServiceUrl
};
return(r);
}