Implement support for monetized apps.

See discord/discord-api-docs#6451, discord/discord-api-docs#6452,
and discord/discord-api-docs#6477.

Backend/Remora.Discord.API.Abstractions/API/Gateway/Events/Monetization/IEntitlementCreate.cs

@@ -0,0 +1,34 @@
+//
+//  IEntitlementCreate.cs
+//
+//  Author:
+//       Jarl Gullberg <jarl.gullberg@gmail.com>
+//
+//  Copyright (c) Jarl Gullberg
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using JetBrains.Annotations;
+using Remora.Discord.API.Abstractions.Objects;
+
+namespace Remora.Discord.API.Abstractions.Gateway.Events;
+
+/// <summary>
+/// Represents a user's initial subscription to an SKU.
+/// </summary>
+[PublicAPI]
+public interface IEntitlementCreate : IEntitlement, IGatewayEvent
+{
+}

Backend/Remora.Discord.API.Abstractions/API/Gateway/Events/Monetization/IEntitlementDelete.cs

@@ -0,0 +1,34 @@
+//
+//  IEntitlementDelete.cs
+//
+//  Author:
+//       Jarl Gullberg <jarl.gullberg@gmail.com>
+//
+//  Copyright (c) Jarl Gullberg
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using JetBrains.Annotations;
+using Remora.Discord.API.Abstractions.Objects;
+
+namespace Remora.Discord.API.Abstractions.Gateway.Events;
+
+/// <summary>
+/// Represents a removal of an entitlement from a user.
+/// </summary>
+[PublicAPI]
+public interface IEntitlementDelete : IEntitlement, IGatewayEvent
+{
+}

Backend/Remora.Discord.API.Abstractions/API/Gateway/Events/Monetization/IEntitlementUpdate.cs

@@ -0,0 +1,34 @@
+//
+//  IEntitlementUpdate.cs
+//
+//  Author:
+//       Jarl Gullberg <jarl.gullberg@gmail.com>
+//
+//  Copyright (c) Jarl Gullberg
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using JetBrains.Annotations;
+using Remora.Discord.API.Abstractions.Objects;
+
+namespace Remora.Discord.API.Abstractions.Gateway.Events;
+
+/// <summary>
+/// Represents a renewal of a user's entitlement to an SKU.
+/// </summary>
+[PublicAPI]
+public interface IEntitlementUpdate : IEntitlement, IGatewayEvent
+{
+}

Backend/Remora.Discord.API.Abstractions/API/Objects/Interactions/IInteraction.cs

@@ -21,6 +21,7 @@
 //
 
 using System;
+using System.Collections.Generic;
 using JetBrains.Annotations;
 using OneOf;
 using Remora.Rest.Core;
@@ -116,4 +117,9 @@ public interface IInteraction
     /// Gets the locale of the guild the interaction was sent from.
     /// </summary>
     Optional<string> GuildLocale { get; }
+
+    /// <summary>
+    /// Gets, for monetized apps, any entitlements for the invoking user.
+    /// </summary>
+    IReadOnlyList<IEntitlement> Entitlements { get; }
 }

Backend/Remora.Discord.API.Abstractions/API/Objects/Interactions/InteractionCallbackType.cs

@@ -72,5 +72,10 @@ public enum InteractionCallbackType
     /// <remarks>
     /// Only relevant for component-based interactions and application commands.
     /// </remarks>
-    Modal = 9
+    Modal = 9,
+
+    /// <summary>
+    /// Respond to an interaction with an upgrade button. Only available for apps with monetization enabled.
+    /// </summary>
+    PremiumRequired = 10
 }

Backend/Remora.Discord.API.Abstractions/API/Objects/Monetization/EntitlementOwnerType.cs

@@ -0,0 +1,42 @@
+//
+//  EntitlementOwnerType.cs
+//
+//  Author:
+//       Jarl Gullberg <jarl.gullberg@gmail.com>
+//
+//  Copyright (c) Jarl Gullberg
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using JetBrains.Annotations;
+
+namespace Remora.Discord.API.Abstractions.Objects;
+
+/// <summary>
+/// Enumerates various entitlement owner types.
+/// </summary>
+[PublicAPI]
+public enum EntitlementOwnerType
+{
+    /// <summary>
+    /// The entitlement is owned by a guild.
+    /// </summary>
+    Guild = 1,
+
+    /// <summary>
+    /// The entitlement is owned by a user.
+    /// </summary>
+    User = 2
+}

Backend/Remora.Discord.API.Abstractions/API/Objects/Monetization/EntitlementType.cs

@@ -0,0 +1,37 @@
+//
+//  EntitlementType.cs
+//
+//  Author:
+//       Jarl Gullberg <jarl.gullberg@gmail.com>
+//
+//  Copyright (c) Jarl Gullberg
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using JetBrains.Annotations;
+
+namespace Remora.Discord.API.Abstractions.Objects;
+
+/// <summary>
+/// Enumerates various entitlement types.
+/// </summary>
+[PublicAPI]
+public enum EntitlementType
+{
+    /// <summary>
+    /// The entitlement was purchased as an app subscription.
+    /// </summary>
+    ApplicationSubscription = 8
+}

Backend/Remora.Discord.API.Abstractions/API/Objects/Monetization/IEntitlement.cs

@@ -0,0 +1,106 @@
+//
+//  IEntitlement.cs
+//
+//  Author:
+//       Jarl Gullberg <jarl.gullberg@gmail.com>
+//
+//  Copyright (c) Jarl Gullberg
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using System;
+using JetBrains.Annotations;
+using Remora.Rest.Core;
+
+namespace Remora.Discord.API.Abstractions.Objects;
+
+/// <summary>
+/// Represents information about a user's access to monetized application features.
+/// </summary>
+[PublicAPI]
+public interface IEntitlement : IPartialEntitlement
+{
+    /// <summary>
+    /// Gets the ID of the entitlement.
+    /// </summary>
+    new Snowflake ID { get; }
+
+    /// <summary>
+    /// Gets the ID of the SKU.
+    /// </summary>
+    new Snowflake SKUID { get; }
+
+    /// <summary>
+    /// Gets the ID of the parent application.
+    /// </summary>
+    new Snowflake ApplicationID { get; }
+
+    /// <summary>
+    /// Gets the ID of the user that is granted access to the entitlement's SKU.
+    /// </summary>
+    new Optional<Snowflake> UserID { get; }
+
+    /// <summary>
+    /// Gets the type of the entitlement.
+    /// </summary>
+    new EntitlementType Type { get; }
+
+    /// <summary>
+    /// Gets a value indicating whether the entitlement has been deleted.
+    /// </summary>
+    new bool IsDeleted { get; }
+
+    /// <summary>
+    /// Gets the start time at which the entitlement is valid.
+    /// </summary>
+    new Optional<DateTimeOffset> StartsAt { get; }
+
+    /// <summary>
+    /// Gets the end time at which the entitlement is no longer valid.
+    /// </summary>
+    new Optional<DateTimeOffset> EndsAt { get; }
+
+    /// <summary>
+    /// Gets the ID of the guild that is granted access to the entitlement's SKU.
+    /// </summary>
+    new Optional<Snowflake> GuildID { get; }
+
+    /// <inheritdoc/>
+    Optional<Snowflake> IPartialEntitlement.ID => this.ID;
+
+    /// <inheritdoc/>
+    Optional<Snowflake> IPartialEntitlement.SKUID => this.SKUID;
+
+    /// <inheritdoc/>
+    Optional<Snowflake> IPartialEntitlement.UserID => this.UserID;
+
+    /// <inheritdoc/>
+    Optional<Snowflake> IPartialEntitlement.GuildID => this.GuildID;
+
+    /// <inheritdoc/>
+    Optional<Snowflake> IPartialEntitlement.ApplicationID => this.ApplicationID;
+
+    /// <inheritdoc/>
+    Optional<EntitlementType> IPartialEntitlement.Type => this.Type;
+
+    /// <inheritdoc/>
+    Optional<bool> IPartialEntitlement.IsDeleted => this.IsDeleted;
+
+    /// <inheritdoc/>
+    Optional<DateTimeOffset> IPartialEntitlement.StartsAt => this.StartsAt;
+
+    /// <inheritdoc/>
+    Optional<DateTimeOffset> IPartialEntitlement.EndsAt => this.EndsAt;
+}

Backend/Remora.Discord.API.Abstractions/API/Objects/Monetization/IPartialEntitlement.cs

@@ -0,0 +1,61 @@
+//
+//  IPartialEntitlement.cs
+//
+//  Author:
+//       Jarl Gullberg <jarl.gullberg@gmail.com>
+//
+//  Copyright (c) Jarl Gullberg
+//
+//  This program is free software: you can redistribute it and/or modify
+//  it under the terms of the GNU Lesser General Public License as published by
+//  the Free Software Foundation, either version 3 of the License, or
+//  (at your option) any later version.
+//
+//  This program is distributed in the hope that it will be useful,
+//  but WITHOUT ANY WARRANTY; without even the implied warranty of
+//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+//  GNU Lesser General Public License for more details.
+//
+//  You should have received a copy of the GNU Lesser General Public License
+//  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+//
+
+using System;
+using JetBrains.Annotations;
+using Remora.Rest.Core;
+
+namespace Remora.Discord.API.Abstractions.Objects;
+
+/// <summary>
+/// Represents partial information about a user's access to monetized application features.
+/// </summary>
+[PublicAPI]
+public interface IPartialEntitlement
+{
+    /// <inheritdoc cref="IEntitlement.ID"/>
+    Optional<Snowflake> ID { get; }
+
+    /// <inheritdoc cref="IEntitlement.SKUID"/>
+    Optional<Snowflake> SKUID { get; }
+
+    /// <inheritdoc cref="IEntitlement.ApplicationID"/>
+    Optional<Snowflake> ApplicationID { get; }
+
+    /// <inheritdoc cref="IEntitlement.UserID"/>
+    Optional<Snowflake> UserID { get; }
+
+    /// <inheritdoc cref="IEntitlement.Type"/>
+    Optional<EntitlementType> Type { get; }
+
+    /// <inheritdoc cref="IEntitlement.IsDeleted"/>
+    Optional<bool> IsDeleted { get; }
+
+    /// <inheritdoc cref="IEntitlement.StartsAt"/>
+    Optional<DateTimeOffset> StartsAt { get; }
+
+    /// <inheritdoc cref="IEntitlement.EndsAt"/>
+    Optional<DateTimeOffset> EndsAt { get; }
+
+    /// <inheritdoc cref="IEntitlement.GuildID"/>
+    Optional<Snowflake> GuildID { get; }
+}