Implement message Activity and Application model update

src/Discord.Net.Core/Entities/Messages/IMessage.cs

@@ -100,5 +100,25 @@ namespace Discord
         ///     A read-only collection of user IDs.
         /// </returns>
         IReadOnlyCollection<ulong> MentionedUserIds { get; }
+        /// <summary>
+        ///     Returns the Activity associated with a message.
+        /// </summary>
+        /// <remarks>
+        ///     Sent with Rich Presence-related chat embeds.
+        /// </remarks>
+        /// <returns>
+        ///     A message's activity, if any is associated.
+        /// </returns>
+        MessageActivity Activity { get; }
+        /// <summary>
+        ///     Returns the Application associated with a messsage.
+        /// </summary>
+        /// <remarks>
+        ///     Sent with Rich-Presence-related chat embeds.
+        /// </remarks>
+        /// <returns>
+        ///     A message's application, if any is associated.
+        /// </returns>
+        MessageApplication Application { get; }
     }
 }

src/Discord.Net.Core/Entities/Messages/MessageActivity.cs

@@ -0,0 +1,27 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Discord
+{
+    [DebuggerDisplay(@"{DebuggerDisplay,nq}")]
+    public class MessageActivity
+    {
+        /// <summary>
+        ///     Gets the type of activity of this message.
+        /// </summary>
+        public MessageActivityType Type { get; set; }
+        /// <summary>
+        ///     Gets the party ID of this activity, if any.
+        /// </summary>
+        public string PartyId { get; set; }
+
+        private string DebuggerDisplay
+            => $"{Type}{(string.IsNullOrWhiteSpace(PartyId) ? "" : $" {PartyId}")}";
+
+        public override string ToString() => DebuggerDisplay;
+    }
+}

src/Discord.Net.Core/Entities/Messages/MessageActivityType.cs

@@ -0,0 +1,16 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Discord
+{
+    public enum MessageActivityType
+    {
+        Join = 1,
+        Spectate = 2,
+        Listen = 3,
+        JoinRequest = 5
+    }
+}

src/Discord.Net.Core/Entities/Messages/MessageApplication.cs

@@ -0,0 +1,37 @@
+using System;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Discord
+{
+    [DebuggerDisplay(@"{DebuggerDisplay,nq}")]
+    public class MessageApplication
+    {
+        /// <summary>
+        ///     Gets the snowflake ID of the application.
+        /// </summary>
+        public ulong Id { get; set; }
+        /// <summary>
+        ///     Gets the ID of the embed's image asset.
+        /// </summary>
+        public string CoverImage { get; set; }
+        /// <summary>
+        ///     Gets the application's description.
+        /// </summary>
+        public string Description { get; set; }
+        /// <summary>
+        ///     Gets the ID of the application's icon.
+        /// </summary>
+        public string Icon { get; set; }
+        /// <summary>
+        ///     Gets the name of the application.
+        /// </summary>
+        public string Name { get; set; }
+
+        private string DebuggerDisplay
+            => $"{Name} ({Id}): {Description}";
+    }
+}

src/Discord.Net.Rest/API/Common/Message.cs

@@ -44,5 +44,11 @@ namespace Discord.API
         public Optional<bool> Pinned { get; set; }
         [JsonProperty("reactions")]
         public Optional<Reaction[]> Reactions { get; set; }
+        // sent with Rich Presence-related chat embeds
+        [JsonProperty("activity")]
+        public Optional<MessageActivity> Activity { get; set; }
+        // sent with Rich Presence-related chat embeds
+        [JsonProperty("application")]
+        public Optional<MessageApplication> Application { get; set; }
     }
 }

src/Discord.Net.Rest/API/Common/MessageActivity.cs

@@ -0,0 +1,17 @@
+using Newtonsoft.Json;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Discord.API
+{
+    public class MessageActivity
+    {
+        [JsonProperty("type")]
+        public Optional<MessageActivityType> Type { get; set; }
+        [JsonProperty("party_id")]
+        public Optional<string> PartyId { get; set; }
+    }
+}

src/Discord.Net.Rest/API/Common/MessageApplication.cs

@@ -0,0 +1,38 @@
+using Newtonsoft.Json;
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+
+namespace Discord.API
+{
+    public class MessageApplication
+    {
+        /// <summary>
+        ///     Gets the snowflake ID of the application.
+        /// </summary>
+        [JsonProperty("id")]
+        public ulong Id { get; set; }
+        /// <summary>
+        ///     Gets the ID of the embed's image asset.
+        /// </summary>
+        [JsonProperty("cover_image")]
+        public string CoverImage { get; set; }
+        /// <summary>
+        ///     Gets the application's description.
+        /// </summary>
+        [JsonProperty("description")]
+        public string Description { get; set; }
+        /// <summary>
+        ///     Gets the ID of the application's icon.
+        /// </summary>
+        [JsonProperty("icon")]
+        public string Icon { get; set; }
+        /// <summary>
+        ///     Gets the name of the application.
+        /// </summary>
+        [JsonProperty("name")]
+        public string Name { get; set; }
+    }
+}

src/Discord.Net.Rest/Entities/Messages/RestMessage.cs

@@ -55,6 +55,9 @@ namespace Discord.Rest
 
         /// <inheritdoc />
         public DateTimeOffset Timestamp => DateTimeUtils.FromTicks(_timestampTicks);
+        //todo Rest impl
+        public MessageActivity Activity => null;
+        public MessageApplication Application => null;
 
         internal RestMessage(BaseDiscordClient discord, ulong id, IMessageChannel channel, IUser author, MessageSource source)
             : base(discord, id)

src/Discord.Net.WebSocket/Entities/Messages/SocketMessage.cs

@@ -43,6 +43,14 @@ namespace Discord.WebSocket
         public virtual bool IsPinned => false;
         /// <inheritdoc />
         public virtual DateTimeOffset? EditedTimestamp => null;
+
+        /// <inheritdoc />
+        public MessageActivity Activity { get; private set; }
+
+        /// <inheritdoc />
+        public MessageApplication Application { get; private set; }
+
+
         /// <summary>
         ///     Returns all attachments included in this message.
         /// </summary>
@@ -105,6 +113,29 @@ namespace Discord.WebSocket
 
             if (model.Content.IsSpecified)
                 Content = model.Content.Value;
+
+            if (model.Application.IsSpecified)
+            {
+                // create a new Application from the API model
+                Application = new MessageApplication()
+                {
+                    Id = model.Application.Value.Id,
+                    CoverImage = model.Application.Value.CoverImage,
+                    Description = model.Application.Value.Description,
+                    Icon = model.Application.Value.Icon,
+                    Name = model.Application.Value.Name
+                };
+            }
+
+            if (model.Activity.IsSpecified)
+            {
+                // create a new Activity from the API model
+                Activity = new MessageActivity()
+                {
+                    Type = model.Activity.Value.Type.Value,
+                    PartyId = model.Activity.Value.PartyId.Value
+                };
+            }
         }
 
         /// <inheritdoc />