LuisBot.cs

// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License.

using System.Threading;
using System.Threading.Tasks;
using Microsoft.Bot.Builder;
using Microsoft.Bot.Schema;

namespace Microsoft.BotBuilderSamples
{
    /// <summary>
    /// For each interaction from the user, an instance of this class is created and
    /// the OnTurnAsync method is called.
    /// This is a transient lifetime service. Transient lifetime services are created
    /// each time they're requested. For each <see cref="Activity"/> received, a new instance of this
    /// class is created. Objects that are expensive to construct, or have a lifetime
    /// beyond the single turn, should be carefully managed.
    /// </summary>
    /// <seealso cref="https://docs.microsoft.com/en-us/aspnet/core/fundamentals/dependency-injection?view=aspnetcore-2.1"/>
    /// <seealso cref="https://docs.microsoft.com/en-us/dotnet/api/microsoft.bot.ibot?view=botbuilder-dotnet-preview"/>
    public class LuisBot : IBot
    {
        /// <summary>
        /// Key in the bot config (.bot file) for the LUIS instance.
        /// In the .bot file, multiple instances of LUIS can be configured.
        /// </summary>
        public static readonly string LuisKey = "LuisBot";

        private const string WelcomeText = "This bot will introduce you to natural language processing with LUIS. Type an utterance to get started";

        /// <summary>
        /// Services configured from the ".bot" file.
        /// </summary>
        private readonly BotServices _services;

        /// <summary>
        /// Initializes a new instance of the <see cref="LuisBot"/> class.
        /// </summary>
        /// <param name="services">Services configured from the ".bot" file.</param>
        public LuisBot(BotServices services)
        {
            _services = services ?? throw new System.ArgumentNullException(nameof(services));
            if (!_services.LuisServices.ContainsKey(LuisKey))
            {
                throw new System.ArgumentException($"Invalid configuration. Please check your '.bot' file for a LUIS service named '{LuisKey}'.");
            }
        }

        /// <summary>
        /// Every conversation turn for our LUIS Bot will call this method.
        /// There are no dialogs used, the sample only uses "single turn" processing,
        /// meaning a single request and response, with no stateful conversation.
        /// </summary>
        /// <param name="turnContext">A <see cref="ITurnContext"/> containing all the data needed
        /// for processing this conversation turn. </param>
        /// <param name="cancellationToken">(Optional) A <see cref="CancellationToken"/> that can be used by other objects
        /// or threads to receive notice of cancellation.</param>
        /// <returns>A <see cref="Task"/> that represents the work queued to execute.</returns>
        public async Task OnTurnAsync(ITurnContext turnContext, CancellationToken cancellationToken = default(CancellationToken))
        {
            if (turnContext.Activity.Type == ActivityTypes.Message)
            {
                // Check LUIS model
                var recognizerResult = await _services.LuisServices[LuisKey].RecognizeAsync(turnContext, cancellationToken);
                var topIntent = recognizerResult?.GetTopScoringIntent();
                if (topIntent != null && topIntent.HasValue && topIntent.Value.intent != "None")
                {
                    await turnContext.SendActivityAsync($"==>LUIS Top Scoring Intent: {topIntent.Value.intent}, Score: {topIntent.Value.score}\n");
                }
                else
                {
                    var msg = @"No LUIS intents were found.
                            This sample is about identifying two user intents:
                            'Calendar.Add'
                            'Calendar.Find'
                            Try typing 'Add Event' or 'Show me tomorrow'.";
                    await turnContext.SendActivityAsync(msg);
                }
            }
            else if (turnContext.Activity.Type == ActivityTypes.ConversationUpdate)
            {
                // Send a welcome message to the user and tell them what actions they may perform to use this bot
                await SendWelcomeMessageAsync(turnContext, cancellationToken);
            }
            else
            {
                await turnContext.SendActivityAsync($"{turnContext.Activity.Type} event detected", cancellationToken: cancellationToken);
            }
        }

        /// <summary>
        /// On a conversation update activity sent to the bot, the bot will
        /// send a message to the any new user(s) that were added.
        /// </summary>
        /// <param name="turnContext">Provides the <see cref="ITurnContext"/> for the turn of the bot.</param>
        /// <param name="cancellationToken" >(Optional) A <see cref="CancellationToken"/> that can be used by other objects
        /// or threads to receive notice of cancellation.</param>
        /// <returns>>A <see cref="Task"/> representing the operation result of the Turn operation.</returns>
        private static async Task SendWelcomeMessageAsync(ITurnContext turnContext, CancellationToken cancellationToken)
        {
            foreach (var member in turnContext.Activity.MembersAdded)
            {
                if (member.Id != turnContext.Activity.Recipient.Id)
                {
                    await turnContext.SendActivityAsync(
                        $"Welcome to LuisBot {member.Name}. {WelcomeText}",
                        cancellationToken: cancellationToken);
                }
            }
        }
    }
}