Change xml docs, IUserMessage, and other changes

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

@@ -148,11 +148,11 @@ namespace Discord
         MessageApplication Application { get; }
 
         /// <summary>
-        ///     Gets the reference to the original message if it was crossposted.
+        ///     Gets the reference to the original message if it is a crosspost, channel follow add, pin, or reply message.
         /// </summary>
         /// <remarks>
-        ///     Sent with Cross-posted messages, meaning they were published from news channels
-        ///     and received by subscriber channels.
+        ///     Sent with cross-posted messages, meaning they were published from news channels
+        ///     and received by subscriber channels, channel follow adds, pins, and message replies.
         /// </remarks>
         /// <returns>
         ///     A message's reference, if any is associated.

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

@@ -1,5 +1,4 @@
 using System;
-using System.Collections.Generic;
 using System.Threading.Tasks;
 
 namespace Discord
@@ -9,6 +8,14 @@ namespace Discord
     /// </summary>
     public interface IUserMessage : IMessage
     {
+        /// <summary>
+        ///     Gets the referenced message if it is a crosspost, channel follow add, pin, or reply message.
+        /// </summary>
+        /// <returns>
+        ///     The referenced message, if any is associated and still exists.
+        /// </returns>
+        IUserMessage ReferencedMessage { get; }
+
         /// <summary>
         ///     Modifies this message.
         /// </summary>

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

@@ -17,9 +17,10 @@ namespace Discord
         ///     Gets the Channel ID of the original message.
         /// </summary>
         /// <remarks>
-        ///     If there is no referenced channel id, it will be the default value (zero).
+        ///     It only will be the default value (zero) if it was instantiated with a <see langword="null"/> in the constructor.
         /// </remarks>
-        public ulong ChannelId { get; internal set; }
+        public ulong ChannelId { get => InternalChannelId.GetValueOrDefault(); }
+        internal Optional<ulong> InternalChannelId;
 
         /// <summary>
         ///     Gets the Guild ID of the original message.
@@ -41,7 +42,7 @@ namespace Discord
         public MessageReference(ulong? messageId = null, ulong? channelId = null, ulong? guildId = null)
         {
             MessageId = messageId ?? Optional.Create<ulong>();
-            ChannelId = channelId ?? default(ulong);
+            InternalChannelId = channelId ?? Optional.Create<ulong>();
             GuildId = guildId ?? Optional.Create<ulong>();
         }
 

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

@@ -63,6 +63,6 @@ namespace Discord
         /// <remarks>
         ///     Only available in API v8.
         /// </remarks>
-        InlineReply = 19,
+        Reply = 19,
     }
 }

src/Discord.Net.Core/Extensions/MessageExtensions.cs

@@ -71,5 +71,25 @@ namespace Discord
             foreach (var rxn in reactions)
                 await msg.RemoveReactionAsync(rxn, user, options).ConfigureAwait(false);
         }
+
+        /// <summary>
+        ///     Sends an inline reply that references a message.
+        /// </summary>
+        /// <param name="text">The message to be sent.</param>
+        /// <param name="isTTS">Determines whether the message should be read aloud by Discord or not.</param>
+        /// <param name="embed">The <see cref="Discord.EmbedType.Rich"/> <see cref="Embed"/> to be sent.</param>
+        /// <param name="allowedMentions">
+        ///     Specifies if notifications are sent for mentioned users and roles in the message <paramref name="text"/>.
+        ///     If <c>null</c>, all mentioned roles and users will be notified.
+        /// </param>
+        /// <param name="options">The options to be used when sending the request.</param>
+        /// <returns>
+        ///     A task that represents an asynchronous send operation for delivering the message. The task result
+        ///     contains the sent message.
+        /// </returns>
+        public static async Task<IUserMessage> ReplyAsync(this IUserMessage msg, string text = null, bool isTTS = false, Embed embed = null, AllowedMentions allowedMentions = null, RequestOptions options = null)
+        {
+            return await msg.Channel.SendMessageAsync(text, isTTS, embed, options, allowedMentions, new MessageReference(messageId: msg.Id)).ConfigureAwait(false);
+        }
     }
 }

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

@@ -8,7 +8,7 @@ namespace Discord.API
         public Optional<ulong> MessageId { get; set; }
 
         [JsonProperty("channel_id")]
-        public Optional<ulong> ChannelId { get; set; }
+        public Optional<ulong> ChannelId { get; set; } // Optional when sending, always present when receiving
 
         [JsonProperty("guild_id")]
         public Optional<ulong> GuildId { get; set; }

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

@@ -282,7 +282,7 @@ namespace Discord.Rest
 
         public static MessageSource GetSource(Model msg)
         {
-            if (msg.Type != MessageType.Default)
+            if (msg.Type != MessageType.Default && msg.Type != MessageType.Reply)
                 return MessageSource.System;
             else if (msg.WebhookId.IsSpecified)
                 return MessageSource.Webhook;

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

@@ -77,7 +77,7 @@ namespace Discord.Rest
         }
         internal static RestMessage Create(BaseDiscordClient discord, IMessageChannel channel, IUser author, Model model)
         {
-            if (model.Type == MessageType.Default)
+            if (model.Type == MessageType.Default || model.Type == MessageType.Reply)
                 return RestUserMessage.Create(discord, channel, author, model);
             else
                 return RestSystemMessage.Create(discord, channel, author, model);
@@ -119,7 +119,7 @@ namespace Discord.Rest
                 Reference = new MessageReference
                 {
                     GuildId = model.Reference.Value.GuildId,
-                    ChannelId = model.Reference.Value.ChannelId.GetValueOrDefault(),
+                    InternalChannelId = model.Reference.Value.ChannelId,
                     MessageId = model.Reference.Value.MessageId
                 };
             }

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

@@ -15,6 +15,7 @@ namespace Discord.Rest
     {
         private bool _isMentioningEveryone, _isTTS, _isPinned, _isSuppressed;
         private long? _editedTimestampTicks;
+        private IUserMessage _referencedMessage;
         private ImmutableArray<Attachment> _attachments = ImmutableArray.Create<Attachment>();
         private ImmutableArray<Embed> _embeds = ImmutableArray.Create<Embed>();
         private ImmutableArray<ITag> _tags = ImmutableArray.Create<ITag>();
@@ -43,6 +44,8 @@ namespace Discord.Rest
         public override IReadOnlyCollection<RestUser> MentionedUsers => _userMentions;
         /// <inheritdoc />
         public override IReadOnlyCollection<ITag> Tags => _tags;
+        /// <inheritdoc />
+        public IUserMessage ReferencedMessage => _referencedMessage;
 
         internal RestUserMessage(BaseDiscordClient discord, ulong id, IMessageChannel channel, IUser author, MessageSource source)
             : base(discord, id, channel, author, source)
@@ -126,6 +129,9 @@ namespace Discord.Rest
                 _tags = MessageHelper.ParseTags(text, null, guild, _userMentions);
                 model.Content = text;
             }
+
+            if (model.ReferencedMessage.IsSpecified && model.ReferencedMessage.Value != null)
+                _referencedMessage = RestUserMessage.Create(Discord, Channel, Author, model.ReferencedMessage.Value);
         }
 
         /// <inheritdoc />

src/Discord.Net.Rest/Extensions/EntityExtensions.cs

@@ -75,7 +75,7 @@ namespace Discord.Rest
         {
             return new API.MessageReference()
             {
-                ChannelId = entity.ChannelId == default(ulong) ? Optional.Create<ulong>() : entity.ChannelId,
+                ChannelId = entity.InternalChannelId,
                 GuildId = entity.GuildId,
                 MessageId = entity.MessageId,
             };

src/Discord.Net.WebSocket/DiscordSocketConfig.cs

@@ -151,7 +151,6 @@ namespace Discord.WebSocket
         }
         private int _maxWaitForGuildAvailable = 10000;
 
-        /// <summary>
         ///    Gets or sets gateway intents to limit what events are sent from Discord. Allows for more granular control than the <see cref="GuildSubscriptions"/> property.
         /// </summary>
         /// <remarks>

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

@@ -110,7 +110,7 @@ namespace Discord.WebSocket
         }
         internal static SocketMessage Create(DiscordSocketClient discord, ClientState state, SocketUser author, ISocketMessageChannel channel, Model model)
         {
-            if (model.Type == MessageType.Default)
+            if (model.Type == MessageType.Default || model.Type == MessageType.Reply)
                 return SocketUserMessage.Create(discord, state, author, channel, model);
             else
                 return SocketSystemMessage.Create(discord, state, author, channel, model);

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

@@ -17,6 +17,7 @@ namespace Discord.WebSocket
     {
         private bool _isMentioningEveryone, _isTTS, _isPinned, _isSuppressed;
         private long? _editedTimestampTicks;
+        private IUserMessage _referencedMessage;
         private ImmutableArray<Attachment> _attachments = ImmutableArray.Create<Attachment>();
         private ImmutableArray<Embed> _embeds = ImmutableArray.Create<Embed>();
         private ImmutableArray<ITag> _tags = ImmutableArray.Create<ITag>();
@@ -45,6 +46,8 @@ namespace Discord.WebSocket
         public override IReadOnlyCollection<SocketRole> MentionedRoles => _roleMentions;
         /// <inheritdoc />
         public override IReadOnlyCollection<SocketUser> MentionedUsers => _userMentions;
+        /// <inheritdoc />
+        public IUserMessage ReferencedMessage => _referencedMessage;
 
         internal SocketUserMessage(DiscordSocketClient discord, ulong id, ISocketMessageChannel channel, SocketUser author, MessageSource source)
             : base(discord, id, channel, author, source)
@@ -131,6 +134,9 @@ namespace Discord.WebSocket
                 _tags = MessageHelper.ParseTags(text, Channel, guild, _userMentions);
                 model.Content = text;
             }
+
+            if (model.ReferencedMessage.IsSpecified && model.ReferencedMessage.Value != null)
+                _referencedMessage = RestUserMessage.Create(Discord, Channel, Author, model.ReferencedMessage.Value);
         }
 
         /// <inheritdoc />