Implement data structures for forwarding

Backend/Remora.Discord.API.Abstractions/API/Objects/Messages/IMessage.cs

@@ -154,6 +154,11 @@ public interface IMessage : IPartialMessage
     /// </summary>
     new Optional<IMessageReference> MessageReference { get; }
 
+    /// <summary>
+    /// Gets the message associated with <see cref="MessageReference"/>. Sent with forwarded messages.
+    /// </summary>
+    new Optional<IReadOnlyList<IMessageSnapshot>> MessageSnapshots { get; }
+
     /// <summary>
     /// Gets a set of bitwise flags describing extra features of the message.
     /// </summary>
@@ -270,6 +275,9 @@ public interface IMessage : IPartialMessage
     /// <inheritdoc/>
     Optional<IMessageReference> IPartialMessage.MessageReference => this.MessageReference;
 
+    /// <inheritdoc/>
+    Optional<IReadOnlyList<IMessageSnapshot>> IPartialMessage.MessageSnapshots => this.MessageSnapshots;
+
     /// <inheritdoc/>
     Optional<MessageFlags> IPartialMessage.Flags => this.Flags;
 

Backend/Remora.Discord.API.Abstractions/API/Objects/Messages/IMessageReference.cs

@@ -31,6 +31,11 @@ namespace Remora.Discord.API.Abstractions.Objects;
 [PublicAPI]
 public interface IMessageReference
 {
+    /// <summary>
+    /// Gets the type of message reference provided.
+    /// </summary>
+    Optional<MessageReferenceType> Type { get; }
+
     /// <summary>
     /// Gets the ID of the originating message.
     /// </summary>

Backend/Remora.Discord.API.Abstractions/API/Objects/Messages/IMessageSnapshot.cs

@@ -0,0 +1,37 @@
+//
+//  IMessageSnapshot.cs
+//
+//  Author:
+//       Jarl Gullberg <[email protected]>
+//
+//  Copyright (c) Jarl Gullberg
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using JetBrains.Annotations;
+
+namespace Remora.Discord.API.Abstractions.Objects;
+
+/// <summary>
+/// Represents a message at a specific point in time.
+/// </summary>
+[PublicAPI]
+public interface IMessageSnapshot
+{
+    /// <summary>
+    /// Gets the message that has been referenced.
+    /// </summary>
+    IPartialMessage Message { get; }
+}

Backend/Remora.Discord.API.Abstractions/API/Objects/Messages/IPartialMessage.cs

@@ -100,6 +100,9 @@ public interface IPartialMessage
     /// <inheritdoc cref="IMessage.MessageReference" />
     Optional<IMessageReference> MessageReference { get; }
 
+    /// <inheritdoc cref="IMessage.MessageSnapshots" />
+    Optional<IReadOnlyList<IMessageSnapshot>> MessageSnapshots { get; }
+
     /// <inheritdoc cref="IMessage.Flags" />
     Optional<MessageFlags> Flags { get; }
 

Backend/Remora.Discord.API.Abstractions/API/Objects/Messages/MessageReferenceType.cs

@@ -0,0 +1,42 @@
+//
+//  MessageReferenceType.cs
+//
+//  Author:
+//       Jarl Gullberg <[email protected]>
+//
+//  Copyright (c) Jarl Gullberg
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using JetBrains.Annotations;
+
+namespace Remora.Discord.API.Abstractions.Objects;
+
+/// <summary>
+/// Enumerates the message reference types provided by Discord.
+/// </summary>
+[PublicAPI]
+public enum MessageReferenceType
+{
+    /// <summary>
+    /// A reference used by replies.
+    /// </summary>
+    Default = 0,
+
+    /// <summary>
+    /// A reference used to point to a message at a point in time.
+    /// </summary>
+    Forward = 1,
+}

Backend/Remora.Discord.API/API/Gateway/Events/Messages/MessageCreate.cs

@@ -60,6 +60,7 @@ public record MessageCreate
     Optional<IMessageReference> MessageReference = default,
     Optional<MessageFlags> Flags = default,
     Optional<IMessage?> ReferencedMessage = default,
+    Optional<IReadOnlyList<IMessageSnapshot>> MessageSnapshots = default,
     Optional<IMessageInteraction> Interaction = default,
     Optional<IChannel> Thread = default,
     Optional<IReadOnlyList<IMessageComponent>> Components = default,

Backend/Remora.Discord.API/API/Gateway/Events/Messages/MessageUpdate.cs

@@ -58,6 +58,7 @@ public record MessageUpdate
     Optional<IPartialApplication> Application = default,
     Optional<Snowflake> ApplicationID = default,
     Optional<IMessageReference> MessageReference = default,
+    Optional<IReadOnlyList<IMessageSnapshot>> MessageSnapshots = default,
     Optional<MessageFlags> Flags = default,
     Optional<IMessage?> ReferencedMessage = default,
     Optional<IMessageInteraction> Interaction = default,

Backend/Remora.Discord.API/API/Objects/Messages/Message.cs

@@ -59,6 +59,7 @@ public record Message
     Optional<IMessageReference> MessageReference = default,
     Optional<MessageFlags> Flags = default,
     Optional<IMessage?> ReferencedMessage = default,
+    Optional<IReadOnlyList<IMessageSnapshot>> MessageSnapshots = default,
     Optional<IMessageInteraction> Interaction = default,
     Optional<IChannel> Thread = default,
     Optional<IReadOnlyList<IMessageComponent>> Components = default,

Backend/Remora.Discord.API/API/Objects/Messages/MessageReference.cs

@@ -32,6 +32,7 @@ namespace Remora.Discord.API.Objects;
 [PublicAPI]
 public record MessageReference
 (
+    Optional<MessageReferenceType> Type = default,
     Optional<Snowflake> MessageID = default,
     Optional<Snowflake> ChannelID = default,
     Optional<Snowflake> GuildID = default,

Backend/Remora.Discord.API/API/Objects/Messages/PartialMessage.cs

@@ -57,6 +57,7 @@ public record PartialMessage
     Optional<IPartialApplication> Application = default,
     Optional<Snowflake> ApplicationID = default,
     Optional<IMessageReference> MessageReference = default,
+    Optional<IReadOnlyList<IMessageSnapshot>> MessageSnapshots = default,
     Optional<MessageFlags> Flags = default,
     Optional<IMessage?> ReferencedMessage = default,
     Optional<IMessageInteraction> Interaction = default,

Tests/Remora.Discord.Tests/Samples/Gateway/Events/MESSAGE_CREATE/MESSAGE_CREATE.json

@@ -87,6 +87,7 @@
       "pinned": true,
       "type": 1
     },
+    "message_snapshots": [],
     "interaction": {
       "id": "999999999999999999",
       "type": 1,

Tests/Remora.Discord.Tests/Samples/Gateway/Events/MESSAGE_CREATE/MESSAGE_CREATE.nulls.json

@@ -67,6 +67,7 @@
     "message_reference": {},
     "flags": 1,
     "referenced_message": null,
+    "message_snapshots": null,
     "interaction": {
       "id": "999999999999999999",
       "type": 1,

Tests/Remora.Discord.Tests/Samples/Objects/MESSAGE/MESSAGE.json

@@ -91,6 +91,7 @@
     "pinned": true,
     "type": 1
   },
+  "message_snapshots": [],
   "interaction": {
     "id": "999999999999999999",
     "type": 1,

Tests/Remora.Discord.Tests/Samples/Objects/MESSAGE/MESSAGE.nulls.json

@@ -71,6 +71,7 @@
   "message_reference": {},
   "flags": 1,
   "referenced_message": null,
+  "message_snapshots": null,
   "interaction": {
     "id": "999999999999999999",
     "type": 1,