[Feature] Premium subscriptions (#2781)

* what a big commit lel, add app sub enums

* work

* ah yup lol

* `?`

* events 1

* typo

* `list` => `get` | remaining events

* add `RespondWithPremiumRequiredAsync` to interaction module base

src/Discord.Net.Core/DiscordConfig.cs

@@ -237,5 +237,10 @@ namespace Discord
         ///     Returns the max amount of tags applied to an application.
         /// </summary>
         public const int MaxApplicationTagCount = 5;
+
+        /// <summary>
+        ///     Returns the maximum number of entitlements that can be gotten per-batch.
+        /// </summary>
+        public const int MaxEntitlementsPerBatch = 100;
     }
 }

src/Discord.Net.Core/Entities/AppSubscriptions/EntitlementType.cs

@@ -0,0 +1,9 @@
+namespace Discord;
+
+public enum EntitlementType
+{
+    /// <summary>
+    ///     The entitlement was purchased as an app subscription.
+    /// </summary>
+    ApplicationSubscription = 8
+}

src/Discord.Net.Core/Entities/AppSubscriptions/IEntitlement.cs

@@ -0,0 +1,61 @@
+using System;
+
+namespace Discord;
+
+public interface IEntitlement : ISnowflakeEntity
+{
+    /// <summary>
+    ///     Gets the ID of the SKU this entitlement is for.
+    /// </summary>
+    ulong SkuId { get; }
+
+    /// <summary>
+    ///     Gets the ID of the user that is granted access to the entitlement's SKU.
+    /// </summary>
+    /// <remarks>
+    ///     <see langword="null"/> if the entitlement is for a guild.
+    /// </remarks>
+    ulong? UserId { get; }
+
+    /// <summary>
+    ///     Gets the ID of the guild that is granted access to the entitlement's SKU.
+    /// </summary> 
+    /// <remarks>
+    ///     <see langword="null"/> if the entitlement is for a user.
+    /// </remarks>
+    ulong? GuildId { get; }
+
+    /// <summary>
+    ///     Gets the ID of the parent application.
+    /// </summary>
+    ulong ApplicationId { get; }
+
+    /// <summary>
+    ///     Gets the type of the entitlement.
+    /// </summary>
+    EntitlementType Type { get; }
+
+    /// <summary>
+    ///     Gets whether this entitlement has been consumed.
+    /// </summary>
+    /// <remarks>
+    ///     Not applicable for App Subscriptions.
+    /// </remarks>
+    bool IsConsumed { get; }
+
+    /// <summary>
+    ///     Gets the start date at which the entitlement is valid.
+    /// </summary>
+    /// <remarks>
+    ///     <see langword="null"/> when using test entitlements.
+    /// </remarks>
+    DateTimeOffset? StartsAt { get; }
+
+    /// <summary>
+    ///     Gets the end date at which the entitlement is no longer valid.
+    /// </summary>
+    /// <remarks>
+    ///     <see langword="null"/> when using test entitlements.
+    /// </remarks>
+    DateTimeOffset? EndsAt { get; }
+}

src/Discord.Net.Core/Entities/AppSubscriptions/SKU.cs

@@ -0,0 +1,41 @@
+using System;
+
+namespace Discord;
+
+public struct SKU : ISnowflakeEntity
+{
+    /// <inheritdoc />
+    public ulong Id { get; }
+
+    /// <inheritdoc />
+    public DateTimeOffset CreatedAt => SnowflakeUtils.FromSnowflake(Id);
+
+    /// <summary>
+    ///     Gets the type of the SKU.
+    /// </summary>
+    public SKUType Type { get; }
+
+    /// <summary>
+    ///     Gets the ID of the parent application.
+    /// </summary>
+    public ulong ApplicationId { get; }
+
+    /// <summary>
+    ///     Gets the customer-facing name of your premium offering.
+    /// </summary>
+    public string Name { get; }
+
+    /// <summary>
+    ///     Gets the system-generated URL slug based on the SKU's name.
+    /// </summary>
+    public string Slug { get; }
+
+    internal SKU(ulong id, SKUType type, ulong applicationId, string name, string slug)
+    {
+        Id = id;
+        Type = type;
+        ApplicationId = applicationId;
+        Name = name;
+        Slug = slug;
+    }
+}

src/Discord.Net.Core/Entities/AppSubscriptions/SKUFlags.cs

@@ -0,0 +1,11 @@
+using System;
+
+namespace Discord;
+
+[Flags]
+public enum SKUFlags
+{
+    GuildSubscription = 1 << 7,
+
+    UserSubscription = 1 << 8
+}

src/Discord.Net.Core/Entities/AppSubscriptions/SKUType.cs

@@ -0,0 +1,14 @@
+namespace Discord;
+
+public enum SKUType
+{
+    /// <summary>
+    ///     Represents a recurring subscription.
+    /// </summary>
+    Subscription = 5,
+
+    /// <summary>
+    ///     System-generated group for each <see cref="SKUType.Subscription"/> SKU created.
+    /// </summary>
+    SubscriptionGroup = 6,
+}

src/Discord.Net.Core/Entities/AppSubscriptions/SubscriptionOwnerType.cs

@@ -0,0 +1,14 @@
+namespace Discord;
+
+public enum SubscriptionOwnerType
+{
+    /// <summary>
+    ///     The owner of the application subscription is a guild.
+    /// </summary>
+    Guild = 1,
+
+    /// <summary>
+    ///     The owner of the application subscription is a user.
+    /// </summary>
+    User = 2,
+}

src/Discord.Net.Core/Entities/Interactions/IDiscordInteraction.cs

@@ -91,6 +91,11 @@ namespace Discord
         /// </summary>
         ulong ApplicationId { get; }
 
+        /// <summary>
+        ///     Gets entitlements for the invoking user.
+        /// </summary>
+        IReadOnlyCollection<IEntitlement> Entitlements { get; }
+
         /// <summary>
         ///     Responds to an Interaction with type <see cref="InteractionResponseType.ChannelMessageWithSource"/>.
         /// </summary>
@@ -368,5 +373,12 @@ namespace Discord
         /// <param name="options">The request options for this <see langword="async"/> request.</param>
         /// <returns>A task that represents the asynchronous operation of responding to the interaction.</returns>
         Task RespondWithModalAsync(Modal modal, RequestOptions options = null);
+
+        /// <summary>
+        ///     Responds to the interaction with an ephemeral message the invoking user,
+        ///     instructing them that whatever they tried to do requires the premium benefits of your app.
+        /// </summary>
+        /// <returns>A task that represents the asynchronous operation of responding to the interaction.</returns>
+        Task RespondWithPremiumRequiredAsync(RequestOptions options = null);
     }
 }

src/Discord.Net.Core/Entities/Interactions/InteractionResponseType.cs

@@ -47,5 +47,10 @@ namespace Discord
         ///     Respond by showing the user a modal.
         /// </summary>
         Modal = 9,
+
+        /// <summary>
+        ///     Respond to an interaction with an upgrade button, only available for apps with monetization enabled.
+        /// </summary>
+        PremiumRequired = 10
     }
 }

src/Discord.Net.Core/IDiscordClient.cs

@@ -327,5 +327,27 @@ namespace Discord
         ///     that represents the gateway information related to the bot.
         /// </returns>
         Task<BotGateway> GetBotGatewayAsync(RequestOptions options = null);
+
+        /// <summary>
+        ///     Creates a test entitlement to a given SKU for a given guild or user. 
+        /// </summary>
+        Task<IEntitlement> CreateTestEntitlementAsync(ulong skuId, ulong ownerId, SubscriptionOwnerType ownerType, RequestOptions options = null);
+
+        /// <summary>
+        ///     Deletes a currently-active test entitlement.
+        /// </summary>
+        Task DeleteTestEntitlementAsync(ulong entitlementId, RequestOptions options = null);
+
+        /// <summary>
+        ///     Returns all entitlements for a given app, active and expired.
+        /// </summary>
+        IAsyncEnumerable<IReadOnlyCollection<IEntitlement>> GetEntitlementsAsync(int? limit = 100,
+            ulong? afterId = null, ulong? beforeId = null, bool excludeEnded = false, ulong? guildId = null, ulong? userId = null,
+            ulong[] skuIds = null, RequestOptions options = null);
+
+        /// <summary>
+        ///     Returns all SKUs for a given application. 
+        /// </summary>
+        Task<IReadOnlyCollection<SKU>> GetSKUsAsync(RequestOptions options = null);
     }
 }