[Feature] Add purchase notification (#2942)

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

@@ -0,0 +1,23 @@
+namespace Discord;
+
+/// <summary>
+///     Represents a guild product purchase.
+/// </summary>
+public readonly struct GuildProductPurchase
+{
+    /// <summary>
+    ///     Gets the ID of the listing.
+    /// </summary>
+    public readonly ulong ListingId;
+
+    /// <summary>
+    ///    Gets the name of the product.
+    /// </summary>
+    public readonly string ProductName;
+
+    internal GuildProductPurchase(ulong listingId, string productName)
+    {
+        ListingId = listingId;
+        ProductName = productName;
+    }
+}

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

@@ -226,6 +226,11 @@ namespace Discord
         /// </returns>
         MessageRoleSubscriptionData RoleSubscriptionData { get; }
 
+        /// <summary>
+        ///     Gets the purchase notification for this message.
+        /// </summary>
+        PurchaseNotification PurchaseNotification { get; }
+        
         /// <summary>
         ///     Gets the call data of the message.
         /// </summary>

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

@@ -0,0 +1,23 @@
+namespace Discord;
+
+/// <summary>
+///     Represents a purchase notification.
+/// </summary>
+public readonly struct PurchaseNotification
+{
+    /// <summary>
+    ///     Gets the type of the purchase.
+    /// </summary>
+    public readonly PurchaseType Type;
+
+    /// <summary>
+    ///     Gets the purchased product.
+    /// </summary>
+    public readonly GuildProductPurchase? ProductPurchase;
+
+    internal PurchaseNotification(PurchaseType type, GuildProductPurchase? productPurchase)
+    {
+        Type = type;
+        ProductPurchase = productPurchase;
+    }
+}

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

@@ -0,0 +1,12 @@
+namespace Discord;
+
+/// <summary>
+///     Represents the type of purchase notification.
+/// </summary>
+public enum PurchaseType
+{
+    /// <summary>
+    ///     A guild product purchase.
+    /// </summary>
+    GuildProduct = 0
+}