[Feature] Modal refactoring & select menu support

src/Discord.Net.Core/Entities/Interactions/MessageComponents/Builders/ButtonBuilder.cs

@@ -9,6 +9,7 @@ namespace Discord;
 /// </summary>
 public class ButtonBuilder : IInteractableComponentBuilder
 {
+    /// <inheritdoc />
     public ComponentType Type => ComponentType.Button;
 
     /// <summary>

src/Discord.Net.Core/Entities/Interactions/MessageComponents/Builders/LabelBuilder.cs

@@ -0,0 +1,88 @@
+using System;
+using System.Collections.Immutable;
+using System.Linq;
+
+namespace Discord;
+
+public class LabelBuilder : IMessageComponentBuilder
+{
+    /// <inheritdoc cref="IComponentContainer.SupportedComponentTypes"/>
+    public ImmutableArray<ComponentType> SupportedComponentTypes { get; } =
+    [
+        ComponentType.SelectMenu,
+        ComponentType.TextInput,
+    ];
+
+    /// <summary>
+    ///     The maximum length of the label.
+    /// </summary>
+    public const int MaxLabelLength = 100;
+
+    /// <summary>
+    ///     The maximum length of the description.
+    /// </summary>
+    public const int MaxDescriptionLength = 69420; // TODO: set to the real limit
+
+    /// <inheritdoc />
+    public ComponentType Type => ComponentType.Label;
+
+    /// <inheritdoc />
+    public int? Id { get; set; }
+
+    /// <summary>
+    ///     
+    /// </summary>
+    public string Label { get; set; }
+
+    /// <summary>
+    ///     
+    /// </summary>
+    public string Description { get; set; }
+
+    public IMessageComponentBuilder Component { get; set; }
+
+    /// <summary>
+    ///     Initializes a new <see cref="LabelBuilder"/>.
+    /// </summary>
+    public LabelBuilder() { }
+
+    /// <summary>
+    ///     Initializes a new <see cref="LabelBuilder"/> with the specified content.
+    /// </summary>
+    public LabelBuilder(string label, IMessageComponentBuilder component, string description = null, int? id = null)
+    {
+        Id = id;
+        Label = label;
+        Component = component;
+        Description = description;
+    }
+
+    /// <summary>
+    ///     Initializes a new <see cref="LabelBuilder"/> from existing component.
+    /// </summary>
+    public LabelBuilder(LabelComponent label)
+    {
+        Label = label.Label;
+        Description = label.Description;
+        Id = label.Id;
+        Component = label.Component.ToBuilder();
+    }
+
+    public LabelComponent Build()
+    {
+        Preconditions.NotNullOrWhitespace(Label, nameof(Label));
+        Preconditions.AtMost(Label.Length, MaxLabelLength, nameof(Label));
+
+        Preconditions.AtMost(Description?.Length ?? 0, MaxDescriptionLength, nameof(Description));
+
+        Preconditions.NotNull(Component, nameof(Component));
+
+        if (SupportedComponentTypes.All(x => Component.Type != x))
+            throw new InvalidOperationException($"Component can only be {nameof(SelectMenuBuilder)} or {nameof(TextInputBuilder)}.");
+
+        return new LabelComponent(Id, Label, Description, Component.Build());
+    }
+
+    /// <inheritdoc />
+    IMessageComponent IMessageComponentBuilder.Build() => Build();
+}

src/Discord.Net.Core/Entities/Interactions/MessageComponents/Builders/MediaGalleryBuilder.cs

@@ -18,7 +18,7 @@ public class MediaGalleryBuilder : IMessageComponentBuilder
     /// <inheritdoc/>
     public int? Id { get; set; }
 
-    private List<MediaGalleryItemProperties> _items = new();
+    private List<MediaGalleryItemProperties> _items = [];
 
     /// <summary>
     ///     Initializes a new instance of the <see cref="MediaGalleryBuilder"/>.

src/Discord.Net.Core/Entities/Interactions/MessageComponents/ComponentType.cs

@@ -45,18 +45,44 @@ public enum ComponentType
         /// </summary>
         ChannelSelect = 8,
 
+        /// <summary>
+        ///     A container to display text alongside an accessory component.
+        /// </summary>
         Section = 9,
 
+        /// <summary>
+        ///     A component displaying Markdown text.
+        /// </summary>
         TextDisplay = 10,
 
+        /// <summary>
+        ///     A small image that can be used as an accessory.
+        /// </summary>
         Thumbnail = 11,
 
+        /// <summary>
+        ///     A component displaying images and other media.
+        /// </summary>
         MediaGallery = 12,
 
+        /// <summary>
+        ///     A component displaying an attached file.
+        /// </summary>
         File = 13,
 
+        /// <summary>
+        ///     A component to add vertical padding between other components.
+        /// </summary>
         Separator = 14,
 
+        /// <summary>
+        ///     A container that visually groups a set of components.
+        /// </summary>
         Container = 17,
+
+        /// <summary>
+        ///     
+        /// </summary>
+        Label = 18,
     }
 }

src/Discord.Net.Core/Entities/Interactions/MessageComponents/LabelComponent.cs

@@ -0,0 +1,35 @@
+namespace Discord;
+
+public class LabelComponent : IMessageComponent
+{
+    /// <inheritdoc />
+    public ComponentType Type => ComponentType.Label;
+
+    /// <inheritdoc />
+    public int? Id { get; private set; }
+
+    /// <summary>
+    ///     
+    /// </summary>
+    public string Label { get; private set; }
+
+    /// <summary>
+    ///     
+    /// </summary>
+    public string Description { get; private set; }
+
+    /// <summary>
+    ///     
+    /// </summary>
+    public IMessageComponent Component { get; private set; }
+
+    internal LabelComponent(int? id, string label, string description, IMessageComponent component)
+    {
+        Id = id;
+        Label = label;
+        Description = description;
+        Component = component;
+    }
+
+    public IMessageComponentBuilder ToBuilder() => throw new System.NotImplementedException();
+}

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

@@ -0,0 +1,38 @@
+using Discord.Rest;
+using Newtonsoft.Json;
+
+namespace Discord.API;
+
+internal class LabelComponent : IMessageComponent
+{
+    [JsonProperty("type")]
+    public ComponentType Type { get; set; }
+
+    [JsonProperty("id")]
+    public Optional<int> Id { get; }
+
+    [JsonProperty("label")]
+    public string Label { get; set; }
+
+    [JsonProperty("description")]
+    public string Description { get; set; }
+
+    [JsonProperty("component")]
+    public IMessageComponent Component { get; set; }
+
+    public LabelComponent() {}
+
+    public LabelComponent(Discord.LabelComponent label)
+    {
+        Type = label.Type;
+        Id = label.Id ?? Optional<int>.Unspecified;
+        Label = label.Label;
+        Description = label.Description;
+        Component = label.Component.ToModel();
+    }
+
+    public IMessageComponentBuilder ToBuilder() => null;
+
+    [JsonIgnore]
+    int? IMessageComponent.Id => Id.ToNullable();
+}

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

@@ -41,6 +41,9 @@ internal static IMessageComponent ToModel(this IMessageComponent component)
 
             case ContainerComponent container:
                 return new API.ContainerComponent(container);
+
+            case LabelComponent label:
+                return new API.LabelComponent(label);
         }
 
         return null;
@@ -173,6 +176,12 @@ internal static IMessageComponent ToEntity(this IMessageComponent component)
                     parsed.Id.ToNullable());
             }
 
+            case ComponentType.Label:
+            {
+                var parsed = (API.LabelComponent)component;
+                return new LabelComponent(parsed.Id.ToNullable(), parsed.Label, parsed.Description, parsed.Component.ToEntity());
+            }
+
             default:
                 return null;
         }

src/Discord.Net.Rest/Net/Converters/MessageComponentConverter.cs

@@ -61,6 +61,9 @@ public override object ReadJson(JsonReader reader, Type objectType, object exist
                 case ComponentType.Container:
                     messageComponent = new API.ContainerComponent();
                     break;
+                case ComponentType.Label:
+                    messageComponent = new API.LabelComponent();
+                    break;
             }
             serializer.Populate(jsonObject.CreateReader(), messageComponent);
             return messageComponent;