[Feature] Clips support

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

@@ -1,18 +1,13 @@
+using System;
+using System.Collections.Generic;
+
 namespace Discord
 {
     /// <summary>
     ///     Represents a message attachment found in a <see cref="IUserMessage"/>.
     /// </summary>
-    public interface IAttachment
+    public interface IAttachment : ISnowflakeEntity
     {
-        /// <summary>
-        ///     Gets the ID of this attachment.
-        /// </summary>
-        /// <returns>
-        ///     A snowflake ID associated with this attachment.
-        /// </returns>
-        ulong Id { get; }
-
         /// <summary>
         ///     Gets the filename of this attachment.
         /// </summary>
@@ -85,5 +80,20 @@ public interface IAttachment
         ///     Gets flags related to this to this attachment.
         /// </summary>
         public AttachmentFlags Flags { get; }
+
+        /// <summary>
+        ///     Gets users who participated in the clip.
+        /// </summary>
+        public IReadOnlyCollection<IUser> ClipParticipants { get; }
+
+        /// <summary>
+        ///     Gets the title of the clip. <see langword="null"/> if the clip has no title set.
+        /// </summary>
+        public string Title { get; }
+
+        /// <summary>
+        ///     Gets the timestamp of the clip. <see langword="null"/> if the attachment is not a clip.
+        /// </summary>
+        public DateTimeOffset? ClipCreatedAt { get; }
     }
 }

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

@@ -1,4 +1,5 @@
 using Newtonsoft.Json;
+using System;
 
 namespace Discord.API;
 
@@ -42,4 +43,13 @@ internal class Attachment
 
     [JsonProperty("flags")]
     public Optional<AttachmentFlags> Flags { get; set; }
+
+    [JsonProperty("title")]
+    public Optional<string> Title { get; set; }
+
+    [JsonProperty("clip_created_at")]
+    public Optional<DateTimeOffset> ClipCreatedAt { get; set; }
+
+    [JsonProperty("clip_participants")]
+    public Optional<User[]> ClipParticipants { get; set; }
 }

src/Discord.Net.Rest/Entities/Interactions/CommandBase/RestResolvableData.cs

@@ -113,7 +113,7 @@ internal async Task PopulateAsync(DiscordRestClient discord, RestGuild guild, IR
             {
                 foreach (var attachment in resolved.Attachments.Value)
                 {
-                    var discordAttachment = Attachment.Create(attachment.Value);
+                    var discordAttachment = Attachment.Create(attachment.Value, discord);
 
                     Attachments.Add(ulong.Parse(attachment.Key), discordAttachment);
                 }

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

@@ -1,4 +1,9 @@
+using Discord.Rest;
+using System;
+using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Diagnostics;
+using System.Linq;
 using Model = Discord.API.Attachment;
 
 namespace Discord
@@ -32,11 +37,21 @@ public class Attachment : IAttachment
         /// <inheritdoc />
         public double? Duration { get; }
 
+        /// <inheritdoc cref="IAttachment.ClipParticipants" />
+        public IReadOnlyCollection<RestUser> ClipParticipants { get; }
+
+        /// <inheritdoc />
+        public string Title { get; }
+
+        /// <inheritdoc />
+        public DateTimeOffset? ClipCreatedAt { get; }
+
         /// <inheritdoc />
         public AttachmentFlags Flags { get; }
 
         internal Attachment(ulong id, string filename, string url, string proxyUrl, int size, int? height, int? width,
-            bool? ephemeral, string description, string contentType, double? duration, string waveform, AttachmentFlags flags)
+            bool? ephemeral, string description, string contentType, double? duration, string waveform, AttachmentFlags flags, string title,
+            IReadOnlyCollection<RestUser> clipParticipants, DateTimeOffset? clipCreatedAt)
         {
             Id = id;
             Filename = filename;
@@ -51,19 +66,29 @@ internal Attachment(ulong id, string filename, string url, string proxyUrl, int
             Duration = duration;
             Waveform = waveform;
             Flags = flags;
+            Title = title;
+            ClipParticipants = clipParticipants;
+            ClipCreatedAt = clipCreatedAt;
         }
-        internal static Attachment Create(Model model)
+
+        internal static Attachment Create(Model model, BaseDiscordClient discord)
         {
             return new Attachment(model.Id, model.Filename, model.Url, model.ProxyUrl, model.Size,
-                model.Height.IsSpecified ? model.Height.Value : (int?)null,
-                model.Width.IsSpecified ? model.Width.Value : (int?)null,
+                model.Height.IsSpecified ? model.Height.Value : null,
+                model.Width.IsSpecified ? model.Width.Value : null,
                 model.Ephemeral.ToNullable(), model.Description.GetValueOrDefault(),
                 model.ContentType.GetValueOrDefault(),
                 model.DurationSeconds.IsSpecified ? model.DurationSeconds.Value : null,
                 model.Waveform.GetValueOrDefault(null),
-                model.Flags.GetValueOrDefault(AttachmentFlags.None));
+                model.Flags.GetValueOrDefault(AttachmentFlags.None),
+                model.Title.GetValueOrDefault(null),
+                model.ClipParticipants.GetValueOrDefault(Array.Empty<API.User>()).Select(x => RestUser.Create(discord, x)).ToImmutableArray(),
+                model.ClipCreatedAt.IsSpecified ? model.ClipCreatedAt.Value : null);
         }
 
+        /// <inheritdoc />
+        public DateTimeOffset CreatedAt => SnowflakeUtils.FromSnowflake(Id);
+
         /// <summary>
         ///     Returns the filename of this attachment.
         /// </summary>
@@ -72,5 +97,8 @@ internal static Attachment Create(Model model)
         /// </returns>
         public override string ToString() => Filename;
         private string DebuggerDisplay => $"{Filename} ({Size} bytes)";
+
+        /// <inheritdoc />
+        IReadOnlyCollection<IUser> IAttachment.ClipParticipants => ClipParticipants;
     }
 }

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

@@ -80,7 +80,7 @@ internal override void Update(Model model)
                 {
                     var attachments = ImmutableArray.CreateBuilder<Attachment>(value.Length);
                     for (int i = 0; i < value.Length; i++)
-                        attachments.Add(Attachment.Create(value[i]));
+                        attachments.Add(Attachment.Create(value[i], Discord));
                     _attachments = attachments.ToImmutable();
                 }
                 else

src/Discord.Net.WebSocket/Entities/Interaction/SocketBaseCommand/SocketResolvableData.cs

@@ -130,7 +130,7 @@ internal SocketResolvableData(DiscordSocketClient discord, ulong? guildId, T mod
             {
                 foreach (var attachment in resolved.Attachments.Value)
                 {
-                    var discordAttachment = Attachment.Create(attachment.Value);
+                    var discordAttachment = Attachment.Create(attachment.Value, discord);
 
                     Attachments.Add(ulong.Parse(attachment.Key), discordAttachment);
                 }

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

@@ -84,7 +84,7 @@ internal override void Update(ClientState state, Model model)
                 {
                     var attachments = ImmutableArray.CreateBuilder<Attachment>(value.Length);
                     for (int i = 0; i < value.Length; i++)
-                        attachments.Add(Attachment.Create(value[i]));
+                        attachments.Add(Attachment.Create(value[i], Discord));
                     _attachments = attachments.ToImmutable();
                 }
                 else