From e9174ba9f48e91046aff470873739d8a1fcb686b Mon Sep 17 00:00:00 2001
From: Kyle Spearrin <kyle.spearrin@gmail.com>
Date: Thu, 19 Sep 2019 08:46:26 -0400
Subject: [PATCH] iap pre-purchase check

---
 .../Api/Request/IapCheckRequestModel.cs       | 21 +++++++++++++++++
 src/Core/Models/Business/BillingInfo.cs       |  2 ++
 src/Core/Services/IUserService.cs             |  1 +
 .../Services/Implementations/UserService.cs   | 23 +++++++++++++++++++
 4 files changed, 47 insertions(+)
 create mode 100644 src/Core/Models/Api/Request/IapCheckRequestModel.cs

diff --git a/src/Core/Models/Api/Request/IapCheckRequestModel.cs b/src/Core/Models/Api/Request/IapCheckRequestModel.cs
new file mode 100644
index 0000000000..c96a02486c
--- /dev/null
+++ b/src/Core/Models/Api/Request/IapCheckRequestModel.cs
@@ -0,0 +1,21 @@
+using System.Collections.Generic;
+using System.ComponentModel.DataAnnotations;
+using Bit.Core.Enums;
+
+namespace Bit.Core.Models.Api
+{
+    public class IapCheckRequestModel : IValidatableObject
+    {
+        [Required]
+        public PaymentMethodType? PaymentMethodType { get; set; }
+
+        public IEnumerable<ValidationResult> Validate(ValidationContext validationContext)
+        {
+            if(PaymentMethodType != Enums.PaymentMethodType.AppleInApp)
+            {
+                yield return new ValidationResult("Not a supported in-app purchase payment method.",
+                    new string[] { nameof(PaymentMethodType) });
+            }
+        }
+    }
+}
diff --git a/src/Core/Models/Business/BillingInfo.cs b/src/Core/Models/Business/BillingInfo.cs
index 8629698a86..b94d44ba7b 100644
--- a/src/Core/Models/Business/BillingInfo.cs
+++ b/src/Core/Models/Business/BillingInfo.cs
@@ -15,6 +15,8 @@ namespace Bit.Core.Models.Business
 
         public class BillingSource
         {
+            public BillingSource() { }
+
             public BillingSource(PaymentMethod method)
             {
                 if(method.Card != null)
diff --git a/src/Core/Services/IUserService.cs b/src/Core/Services/IUserService.cs
index 936abb9533..b4486b6564 100644
--- a/src/Core/Services/IUserService.cs
+++ b/src/Core/Services/IUserService.cs
@@ -45,6 +45,7 @@ namespace Bit.Core.Services
         Task SendDeleteConfirmationAsync(string email);
         Task<Tuple<bool, string>> SignUpPremiumAsync(User user, string paymentToken,
             PaymentMethodType paymentMethodType, short additionalStorageGb, UserLicense license);
+        Task IapCheckAsync(User user, PaymentMethodType paymentMethodType);
         Task UpdateLicenseAsync(User user, UserLicense license);
         Task<string> AdjustStorageAsync(User user, short storageAdjustmentGb);
         Task ReplacePaymentMethodAsync(User user, string paymentToken, PaymentMethodType paymentMethodType);
diff --git a/src/Core/Services/Implementations/UserService.cs b/src/Core/Services/Implementations/UserService.cs
index e1e297fcc9..40a213abf3 100644
--- a/src/Core/Services/Implementations/UserService.cs
+++ b/src/Core/Services/Implementations/UserService.cs
@@ -751,6 +751,29 @@ namespace Bit.Core.Services
                 paymentIntentClientSecret);
         }
 
+        public async Task IapCheckAsync(User user, PaymentMethodType paymentMethodType)
+        {
+            if(paymentMethodType != PaymentMethodType.AppleInApp)
+            {
+                throw new BadRequestException("Payment method not supported for in-app purchases.");
+            }
+
+            if(user.Premium)
+            {
+                throw new BadRequestException("Already a premium user.");
+            }
+
+            if(!string.IsNullOrWhiteSpace(user.GatewayCustomerId))
+            {
+                var customerService = new Stripe.CustomerService();
+                var customer = await customerService.GetAsync(user.GatewayCustomerId);
+                if(customer != null && customer.Balance != 0)
+                {
+                    throw new BadRequestException("Customer balance cannot exist when using in-app purchases.");
+                }
+            }
+        }
+
         public async Task UpdateLicenseAsync(User user, UserLicense license)
         {
             if(!_globalSettings.SelfHosted)