Add Teams read receipt event

libraries/Microsoft.Bot.Builder/Teams/TeamsActivityHandler.cs

@@ -755,6 +755,8 @@ protected override Task OnEventActivityAsync(ITurnContext<IEventActivity> turnCo
             {
                 switch (turnContext.Activity.Name)
                 {
+                    case "application/vnd.microsoft.readReceipt":
+                        return OnTeamsReadReceiptAsync(JObject.FromObject(turnContext.Activity.Value).ToObject<ReadReceiptInfo>(), turnContext, cancellationToken);
                     case "application/vnd.microsoft.meetingStart":
                         return OnTeamsMeetingStartAsync(JObject.FromObject(turnContext.Activity.Value).ToObject<MeetingStartEventDetails>(), turnContext, cancellationToken);
                     case "application/vnd.microsoft.meetingEnd":
@@ -793,6 +795,20 @@ protected virtual Task OnTeamsMeetingEndAsync(MeetingEndEventDetails meeting, IT
             return Task.CompletedTask;
         }
 
+        /// <summary>
+        /// Invoked when a read receipt for a previously sent message is received from the connector.
+        /// Override this in a derived class to provide logic for when the bot receives a read receipt event.
+        /// </summary>
+        /// <param name="readReceiptInfo">Information regarding the read receipt. i.e. Id of the message last read by the user.</param>
+        /// <param name="turnContext">A strongly-typed context object for this turn.</param>
+        /// <param name="cancellationToken">A cancellation token that can be used by other objects
+        /// or threads to receive notice of cancellation.</param>
+        /// <returns>A task that represents the work queued to execute.</returns>
+        protected virtual Task OnTeamsReadReceiptAsync(ReadReceiptInfo readReceiptInfo, ITurnContext<IEventActivity> turnContext, CancellationToken cancellationToken)
+        {
+            return Task.CompletedTask;
+        }
+
         /// <summary>
         /// Safely casts an object to an object of type <typeparamref name="T"/> .
         /// </summary>

libraries/Microsoft.Bot.Schema/Teams/ReadReceiptInfo.cs

@@ -0,0 +1,81 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+using Newtonsoft.Json;
+
+namespace Microsoft.Bot.Schema.Teams
+{
+    /// <summary>
+    /// General information about a read receipt.
+    /// </summary>
+    public partial class ReadReceiptInfo
+    {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ReadReceiptInfo"/> class.
+        /// </summary>
+        public ReadReceiptInfo()
+        {
+            CustomInit();
+        }
+
+        /// <summary>
+        /// Initializes a new instance of the <see cref="ReadReceiptInfo"/> class.
+        /// </summary>
+        /// <param name="lastReadMessageId">The id of the last read message.</param>
+        public ReadReceiptInfo(string lastReadMessageId)
+        {
+            LastReadMessageId = lastReadMessageId;
+            CustomInit();
+        }
+
+        /// <summary>
+        /// Gets or sets the id of the last read message.
+        /// </summary>
+        /// <value>
+        /// The id of the last read message.
+        /// </value>
+        [JsonProperty(PropertyName = "lastReadMessageId")]
+        public string LastReadMessageId { get; set; }
+
+        /// <summary>
+        /// Helper method useful for determining if a message has been read. This method
+        /// converts the strings to longs. If the compareMessageId is less than or equal to
+        /// the lastReadMessageId, then the message has been read.
+        /// </summary>
+        /// <param name="compareMessageId">The id of the message to compare.</param>
+        /// <param name="lastReadMessageId">The id of the last message read by the user.</param>
+        /// <returns>True if the compareMessageId is less than or equal to the lastReadMessageId.</returns>
+        public static bool IsMessageRead(string compareMessageId, string lastReadMessageId)
+        {
+            if (string.IsNullOrEmpty(compareMessageId) || string.IsNullOrEmpty(lastReadMessageId))
+            {
+                return false;
+            }
+
+            if (long.TryParse(compareMessageId, out long compareMessageIdLong)
+                && long.TryParse(lastReadMessageId, out long lastReadMessageIdLong))
+            {
+                // if compareMessageId is smaller than lastReadMessageId, it means the user read the bot's message. 
+                return (compareMessageIdLong.CompareTo(lastReadMessageIdLong) <= 0) ? true : false;
+            }
+
+            return false;
+        }
+
+        /// <summary>
+        /// Helper method useful for determining if a message has been read.
+        /// If the compareMessageId is less than or equal to the LastReadMessageId,
+        /// then the message has been read.
+        /// </summary>
+        /// <param name="compareMessageId">The id of the message to compare.</param>
+        /// <returns>True if the compareMessageId is less than or equal to the lastReadMessageId.</returns>
+        public bool IsMessageRead(string compareMessageId)
+        {
+            return IsMessageRead(compareMessageId, LastReadMessageId);
+        }
+
+        /// <summary>
+        /// An initialization method that performs custom operations like setting defaults.
+        /// </summary>
+        partial void CustomInit();
+    }
+}

tests/Microsoft.Bot.Builder.Tests/Teams/TeamsActivityHandlerTests.cs

@@ -1138,6 +1138,39 @@ void CaptureSend(Activity[] arg)
             Assert.Contains("1:02:03 AM", activitiesToSend[0].Text); // Date format differs between OSs, so we just Assert.Contains instead of Assert.Equals
         }
 
+        [Fact]
+        public async Task TeamsReadReceiptEvent()
+        {
+            // Arrange
+            var activity = new Activity
+            {
+                ChannelId = Channels.Msteams,
+                Type = ActivityTypes.Event,
+                Name = "application/vnd.microsoft.readReceipt",
+                Value = JObject.Parse(@"{""lastReadMessageId"":""10101010""}"),
+            };
+
+            Activity[] activitiesToSend = null;
+            void CaptureSend(Activity[] arg)
+            {
+                activitiesToSend = arg;
+            }
+
+            var turnContext = new TurnContext(new SimpleAdapter(CaptureSend), activity);
+
+            // Act
+            var bot = new TestActivityHandler();
+            await ((IBot)bot).OnTurnAsync(turnContext);
+
+            // Assert
+            Assert.Equal(2, bot.Record.Count);
+            Assert.Equal("OnEventActivityAsync", bot.Record[0]);
+            Assert.Equal("OnTeamsReadReceiptAsync", bot.Record[1]);
+            Assert.NotNull(activitiesToSend);
+            Assert.Single(activitiesToSend);
+            Assert.Equal("10101010", activitiesToSend[0].Text);
+        }
+
         private class NotImplementedAdapter : BotAdapter
         {
             public override Task DeleteActivityAsync(ITurnContext turnContext, ConversationReference reference, CancellationToken cancellationToken)
@@ -1251,6 +1284,13 @@ protected override Task OnMembersRemovedAsync(IList<ChannelAccount> membersRemov
                 return Task.CompletedTask;
             }
 
+            protected override Task OnTeamsReadReceiptAsync(ReadReceiptInfo readReceiptInfo, ITurnContext<IEventActivity> turnContext, CancellationToken cancellationToken)
+            {
+                Record.Add(MethodBase.GetCurrentMethod().Name);
+                turnContext.SendActivityAsync(readReceiptInfo.LastReadMessageId);
+                return Task.CompletedTask;
+            }
+
             // Invoke
             protected override Task<InvokeResponse> OnInvokeActivityAsync(ITurnContext<IInvokeActivity> turnContext, CancellationToken cancellationToken)
             {

tests/Microsoft.Bot.Schema.Tests/Teams/ReadReceiptInfoTests.cs

@@ -0,0 +1,26 @@
+// Copyright (c) Microsoft Corporation. All rights reserved.
+// Licensed under the MIT License.
+
+using Microsoft.Bot.Schema.Teams;
+using Xunit;
+
+namespace Microsoft.Bot.Schema.Tests.Teams
+{
+    public class ReadReceiptInfoTests
+    {
+        [Theory]
+        [InlineData("1000", "1000", true)]
+        [InlineData("1001", "1000", true)]
+        [InlineData("1000", "1001", false)]
+        [InlineData("1000", null, false)]
+        [InlineData(null, "1000", false)]
+        public void ReadReceiptInfoTest(string lastRead, string compare, bool isRead)
+        {
+            var info = new ReadReceiptInfo(lastRead);
+
+            Assert.Equal(info.LastReadMessageId, lastRead);
+            Assert.Equal(info.IsMessageRead(compare), isRead);
+            Assert.Equal(ReadReceiptInfo.IsMessageRead(compare, lastRead), isRead);
+        }
+    }
+}