(ifcbrk) feature: Add ModifyMessageAsync to IMessageChannel (#1830)

src/Discord.Net.Core/Entities/Channels/IMessageChannel.cs

@@ -257,6 +257,21 @@ namespace Discord
         /// </returns>
         Task DeleteMessageAsync(IMessage message, RequestOptions options = null);
 
+        /// <summary>
+        ///     Modifies a message.
+        /// </summary>
+        /// <remarks>
+        ///     This method modifies this message with the specified properties. To see an example of this
+        ///     method and what properties are available, please refer to <see cref="MessageProperties"/>.
+        /// </remarks>
+        /// <param name="messageId">The snowflake identifier of the message that would be changed.</param>
+        /// <param name="func">A delegate containing the properties to modify the message with.</param>
+        /// <param name="options">The options to be used when sending the request.</param>
+        /// <returns>
+        ///     A task that represents the asynchronous modification operation.
+        /// </returns>
+        Task<IUserMessage> ModifyMessageAsync(ulong messageId, Action<MessageProperties> func, RequestOptions options = null);
+
         /// <summary>
         ///     Broadcasts the "user is typing" message to all users in this channel, lasting 10 seconds.
         /// </summary>

src/Discord.Net.Rest/Entities/Channels/ChannelHelper.cs

@@ -286,6 +286,13 @@ namespace Discord.Rest
             return RestUserMessage.Create(client, channel, client.CurrentUser, model);
         }
 
+        public static async Task<RestUserMessage> ModifyMessageAsync(IMessageChannel channel, ulong messageId, Action<MessageProperties> func,
+            BaseDiscordClient client, RequestOptions options)
+        {
+            var msgModel = await MessageHelper.ModifyAsync(channel.Id, messageId, client, func, options).ConfigureAwait(false);
+            return RestUserMessage.Create(client, channel, msgModel.Author.IsSpecified ? RestUser.Create(client, msgModel.Author.Value) : client.CurrentUser, msgModel);
+        }
+
         public static Task DeleteMessageAsync(IMessageChannel channel, ulong messageId, BaseDiscordClient client,
             RequestOptions options)
             => MessageHelper.DeleteAsync(channel.Id, messageId, client, options);

src/Discord.Net.Rest/Entities/Channels/RestDMChannel.cs

@@ -135,6 +135,10 @@ namespace Discord.Rest
         public Task DeleteMessageAsync(IMessage message, RequestOptions options = null)
             => ChannelHelper.DeleteMessageAsync(this, message.Id, Discord, options);
 
+        /// <inheritdoc />
+        public async Task<IUserMessage> ModifyMessageAsync(ulong messageId, Action<MessageProperties> func, RequestOptions options = null)
+            => await ChannelHelper.ModifyMessageAsync(this, messageId, func, Discord, options).ConfigureAwait(false);
+
         /// <inheritdoc />
         public Task TriggerTypingAsync(RequestOptions options = null)
             => ChannelHelper.TriggerTypingAsync(this, Discord, options);

src/Discord.Net.Rest/Entities/Channels/RestGroupChannel.cs

@@ -93,6 +93,10 @@ namespace Discord.Rest
         public Task DeleteMessageAsync(IMessage message, RequestOptions options = null)
             => ChannelHelper.DeleteMessageAsync(this, message.Id, Discord, options);
 
+        /// <inheritdoc />
+        public async Task<IUserMessage> ModifyMessageAsync(ulong messageId, Action<MessageProperties> func, RequestOptions options = null)
+            => await ChannelHelper.ModifyMessageAsync(this, messageId, func, Discord, options).ConfigureAwait(false);
+
         /// <inheritdoc />
         /// <exception cref="ArgumentOutOfRangeException">Message content is too long, length must be less or equal to <see cref="DiscordConfig.MaxMessageSize"/>.</exception>
         public Task<RestUserMessage> SendMessageAsync(string text = null, bool isTTS = false, Embed embed = null, RequestOptions options = null, AllowedMentions allowedMentions = null, MessageReference messageReference = null)

src/Discord.Net.Rest/Entities/Channels/RestTextChannel.cs

@@ -152,6 +152,10 @@ namespace Discord.Rest
         public Task DeleteMessagesAsync(IEnumerable<ulong> messageIds, RequestOptions options = null)
             => ChannelHelper.DeleteMessagesAsync(this, Discord, messageIds, options);
 
+        /// <inheritdoc />
+        public async Task<IUserMessage> ModifyMessageAsync(ulong messageId, Action<MessageProperties> func, RequestOptions options = null)
+            => await ChannelHelper.ModifyMessageAsync(this, messageId, func, Discord, options).ConfigureAwait(false);
+
         /// <inheritdoc />
         public Task TriggerTypingAsync(RequestOptions options = null)
             => ChannelHelper.TriggerTypingAsync(this, Discord, options);

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

@@ -71,6 +71,48 @@ namespace Discord.Rest
             return await client.ApiClient.ModifyMessageAsync(msg.Channel.Id, msg.Id, apiArgs, options).ConfigureAwait(false);
         }
 
+        public static async Task<Model> ModifyAsync(ulong channelId, ulong msgId, BaseDiscordClient client, Action<MessageProperties> func,
+            RequestOptions options)
+        {
+            var args = new MessageProperties();
+            func(args);
+
+            if ((args.Content.IsSpecified && string.IsNullOrEmpty(args.Content.Value)) && (args.Embed.IsSpecified && args.Embed.Value == null))
+                Preconditions.NotNullOrEmpty(args.Content.IsSpecified ? args.Content.Value : string.Empty, nameof(args.Content));
+
+            if (args.AllowedMentions.IsSpecified)
+            {
+                AllowedMentions allowedMentions = args.AllowedMentions.Value;
+                Preconditions.AtMost(allowedMentions?.RoleIds?.Count ?? 0, 100, nameof(allowedMentions.RoleIds), "A max of 100 role Ids are allowed.");
+                Preconditions.AtMost(allowedMentions?.UserIds?.Count ?? 0, 100, nameof(allowedMentions.UserIds), "A max of 100 user Ids are allowed.");
+
+                // check that user flag and user Id list are exclusive, same with role flag and role Id list
+                if (allowedMentions != null && allowedMentions.AllowedTypes.HasValue)
+                {
+                    if (allowedMentions.AllowedTypes.Value.HasFlag(AllowedMentionTypes.Users) &&
+                        allowedMentions.UserIds != null && allowedMentions.UserIds.Count > 0)
+                    {
+                        throw new ArgumentException("The Users flag is mutually exclusive with the list of User Ids.", nameof(allowedMentions));
+                    }
+
+                    if (allowedMentions.AllowedTypes.Value.HasFlag(AllowedMentionTypes.Roles) &&
+                        allowedMentions.RoleIds != null && allowedMentions.RoleIds.Count > 0)
+                    {
+                        throw new ArgumentException("The Roles flag is mutually exclusive with the list of Role Ids.", nameof(allowedMentions));
+                    }
+                }
+            }
+
+            var apiArgs = new API.Rest.ModifyMessageParams
+            {
+                Content = args.Content,
+                Embed = args.Embed.IsSpecified ? args.Embed.Value.ToModel() : Optional.Create<API.Embed>(),
+                Flags = args.Flags.IsSpecified ? args.Flags.Value : Optional.Create<MessageFlags?>(),
+                AllowedMentions = args.AllowedMentions.IsSpecified ? args.AllowedMentions.Value.ToModel() : Optional.Create<API.AllowedMentions>(),
+            };
+            return await client.ApiClient.ModifyMessageAsync(channelId, msgId, apiArgs, options).ConfigureAwait(false);
+        }
+
         public static Task DeleteAsync(IMessage msg, BaseDiscordClient client, RequestOptions options)
             => DeleteAsync(msg.Channel.Id, msg.Id, client, options);
 

src/Discord.Net.WebSocket/Entities/Channels/SocketDMChannel.cs

@@ -152,6 +152,10 @@ namespace Discord.WebSocket
         public Task DeleteMessageAsync(IMessage message, RequestOptions options = null)
             => ChannelHelper.DeleteMessageAsync(this, message.Id, Discord, options);
 
+        /// <inheritdoc />
+        public async Task<IUserMessage> ModifyMessageAsync(ulong messageId, Action<MessageProperties> func, RequestOptions options = null)
+            => await ChannelHelper.ModifyMessageAsync(this, messageId, func, Discord, options).ConfigureAwait(false);
+
         /// <inheritdoc />
         public Task TriggerTypingAsync(RequestOptions options = null)
             => ChannelHelper.TriggerTypingAsync(this, Discord, options);

src/Discord.Net.WebSocket/Entities/Channels/SocketGroupChannel.cs

@@ -180,6 +180,10 @@ namespace Discord.WebSocket
         public Task DeleteMessageAsync(IMessage message, RequestOptions options = null)
             => ChannelHelper.DeleteMessageAsync(this, message.Id, Discord, options);
 
+        /// <inheritdoc />
+        public async Task<IUserMessage> ModifyMessageAsync(ulong messageId, Action<MessageProperties> func, RequestOptions options = null)
+            => await ChannelHelper.ModifyMessageAsync(this, messageId, func, Discord, options).ConfigureAwait(false);
+
         /// <inheritdoc />
         public Task TriggerTypingAsync(RequestOptions options = null)
             => ChannelHelper.TriggerTypingAsync(this, Discord, options);

src/Discord.Net.WebSocket/Entities/Channels/SocketTextChannel.cs

@@ -180,6 +180,10 @@ namespace Discord.WebSocket
         public Task DeleteMessagesAsync(IEnumerable<ulong> messageIds, RequestOptions options = null)
             => ChannelHelper.DeleteMessagesAsync(this, Discord, messageIds, options);
 
+        /// <inheritdoc />
+        public async Task<IUserMessage> ModifyMessageAsync(ulong messageId, Action<MessageProperties> func, RequestOptions options = null)
+            => await ChannelHelper.ModifyMessageAsync(this, messageId, func, Discord, options).ConfigureAwait(false);
+
         /// <inheritdoc />
         public Task DeleteMessageAsync(ulong messageId, RequestOptions options = null)
             => ChannelHelper.DeleteMessageAsync(this, messageId, Discord, options);

test/Discord.Net.Tests.Unit/MockedEntities/MockedDMChannel.cs

@@ -33,6 +33,11 @@ namespace Discord
             throw new NotImplementedException();
         }
 
+        public Task<IUserMessage> ModifyMessageAsync(ulong messageId, Action<MessageProperties> func, RequestOptions options = null)
+        {
+            throw new NotImplementedException();
+        }
+
         public IDisposable EnterTypingState(RequestOptions options = null)
         {
             throw new NotImplementedException();

test/Discord.Net.Tests.Unit/MockedEntities/MockedGroupChannel.cs

@@ -31,6 +31,11 @@ namespace Discord
             throw new NotImplementedException();
         }
 
+        public Task<IUserMessage> ModifyMessageAsync(ulong messageId, Action<MessageProperties> func, RequestOptions options = null)
+        {
+            throw new NotImplementedException();
+        }
+
         public Task DisconnectAsync()
         {
             throw new NotImplementedException();

test/Discord.Net.Tests.Unit/MockedEntities/MockedTextChannel.cs

@@ -77,6 +77,11 @@ namespace Discord
             throw new NotImplementedException();
         }
 
+        public Task<IUserMessage> ModifyMessageAsync(ulong messageId, Action<MessageProperties> func, RequestOptions options = null)
+        {
+            throw new NotImplementedException();
+        }
+
         public IDisposable EnterTypingState(RequestOptions options = null)
         {
             throw new NotImplementedException();