wip

src/Api/Billing/Controllers/AccountsBillingController.cs

@@ -1,5 +1,6 @@
 #nullable enable
 using Bit.Api.Billing.Models.Responses;
+using Bit.Core.Billing.Models.Api.Requests.Accounts;
 using Bit.Core.Billing.Services;
 using Bit.Core.Services;
 using Bit.Core.Utilities;
@@ -77,4 +78,12 @@ public class AccountsBillingController(
 
         return TypedResults.Ok(transactions);
     }
+
+    [HttpPost("preview-invoice"), AllowAnonymous]
+    public async Task<IResult> PreviewInvoiceAsync([FromBody] PreviewInvoiceRequestBody model)
+    {
+        var invoice = await paymentService.PreviewInvoiceAsync(model);
+
+        return TypedResults.Ok(invoice);
+    }
 }

src/Core/Billing/Extensions/CurrencyExtensions.cs

@@ -0,0 +1,33 @@
+namespace Bit.Core.Billing.Extensions;
+
+public static class CurrencyExtensions
+{
+    /// <summary>
+    /// Converts a currency amount in major units to minor units.
+    /// </summary>
+    /// <example>123.99 USD returns 12399 in minor units.</example>
+    public static long ToMinor(this decimal amount)
+    {
+        return Convert.ToInt64(amount * 100);
+    }
+
+    /// <summary>
+    /// Converts a currency amount in minor units to major units.
+    /// </summary>
+    /// <param name="amount"></param>
+    /// <example>12399 in minor units returns 123.99 USD.</example>
+    public static decimal? ToMajor(this long? amount)
+    {
+        return amount?.ToMajor();
+    }
+
+    /// <summary>
+    /// Converts a currency amount in minor units to major units.
+    /// </summary>
+    /// <param name="amount"></param>
+    /// <example>12399 in minor units returns 123.99 USD.</example>
+    public static decimal ToMajor(this long amount)
+    {
+        return Convert.ToDecimal(amount) / 100;
+    }
+}

src/Core/Billing/Models/Api/Requests/Accounts/PreviewInvoiceRequestModel.cs

@@ -0,0 +1,18 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace Bit.Core.Billing.Models.Api.Requests.Accounts;
+
+public class PreviewInvoiceRequestBody
+{
+    [Required]
+    public PasswordManagerRequestModel PasswordManager { get; set; }
+
+    [Required]
+    public TaxInformationRequestModel TaxInformation { get; set; }
+}
+
+public class PasswordManagerRequestModel
+{
+    [Range(0, int.MaxValue)]
+    public int AdditionalStorage { get; set; }
+}

src/Core/Billing/Models/Api/Requests/TaxInformationRequestModel.cs

@@ -0,0 +1,14 @@
+using System.ComponentModel.DataAnnotations;
+
+namespace Bit.Core.Billing.Models.Api.Requests;
+
+public class TaxInformationRequestModel
+{
+    [Length(2, 2), Required]
+    public string Country { get; set; }
+
+    [Required]
+    public string PostalCode { get; set; }
+
+    public string? TaxId { get; set; }
+}

src/Core/Billing/Models/Api/Responses/PreviewInvoiceResponseModel.cs

@@ -0,0 +1,7 @@
+namespace Bit.Core.Billing.Models.Api.Responses;
+
+public record PreviewInvoiceResponseModel(
+    decimal EffectiveTaxRate,
+    decimal TaxableBaseAmount,
+    decimal TaxAmount,
+    decimal TotalAmount);

src/Core/Billing/Models/PreviewInvoiceInfo.cs

@@ -0,0 +1,7 @@
+namespace Bit.Core.Billing.Models;
+
+public record PreviewInvoiceInfo(
+    decimal EffectiveTaxRate,
+    decimal TaxableBaseAmount,
+    decimal TaxAmount,
+    decimal TotalAmount);

src/Core/Services/IPaymentService.cs

@@ -1,6 +1,8 @@
 using Bit.Core.AdminConsole.Entities;
 using Bit.Core.AdminConsole.Entities.Provider;
 using Bit.Core.Billing.Models;
+using Bit.Core.Billing.Models.Api.Requests.Accounts;
+using Bit.Core.Billing.Models.Api.Responses;
 using Bit.Core.Entities;
 using Bit.Core.Enums;
 using Bit.Core.Models.Business;
@@ -59,4 +61,5 @@ public interface IPaymentService
     Task<bool> RisksSubscriptionFailure(Organization organization);
     Task<bool> HasSecretsManagerStandalone(Organization organization);
     Task<(DateTime?, DateTime?)> GetSuspensionDateAsync(Stripe.Subscription subscription);
+    Task<PreviewInvoiceResponseModel> PreviewInvoiceAsync(PreviewInvoiceRequestBody parameters);
 }

src/Core/Services/IStripeAdapter.cs

@@ -31,6 +31,7 @@ public interface IStripeAdapter
     Task<Stripe.Invoice> InvoiceUpcomingAsync(Stripe.UpcomingInvoiceOptions options);
     Task<Stripe.Invoice> InvoiceGetAsync(string id, Stripe.InvoiceGetOptions options);
     Task<List<Stripe.Invoice>> InvoiceListAsync(StripeInvoiceListOptions options);
+    Task<Stripe.Invoice> InvoiceCreatePreviewAsync(InvoiceCreatePreviewOptions options);
     Task<List<Stripe.Invoice>> InvoiceSearchAsync(InvoiceSearchOptions options);
     Task<Stripe.Invoice> InvoiceUpdateAsync(string id, Stripe.InvoiceUpdateOptions options);
     Task<Stripe.Invoice> InvoiceFinalizeInvoiceAsync(string id, Stripe.InvoiceFinalizeOptions options);
@@ -42,6 +43,7 @@ public interface IStripeAdapter
     IAsyncEnumerable<Stripe.PaymentMethod> PaymentMethodListAutoPagingAsync(Stripe.PaymentMethodListOptions options);
     Task<Stripe.PaymentMethod> PaymentMethodAttachAsync(string id, Stripe.PaymentMethodAttachOptions options = null);
     Task<Stripe.PaymentMethod> PaymentMethodDetachAsync(string id, Stripe.PaymentMethodDetachOptions options = null);
+    Task<Stripe.Plan> PlanGetAsync(string id, Stripe.PlanGetOptions options = null);
     Task<Stripe.TaxRate> TaxRateCreateAsync(Stripe.TaxRateCreateOptions options);
     Task<Stripe.TaxRate> TaxRateUpdateAsync(string id, Stripe.TaxRateUpdateOptions options);
     Task<Stripe.TaxId> TaxIdCreateAsync(string id, Stripe.TaxIdCreateOptions options);

src/Core/Services/Implementations/StripeAdapter.cs

@@ -15,6 +15,7 @@ public class StripeAdapter : IStripeAdapter
     private readonly Stripe.RefundService _refundService;
     private readonly Stripe.CardService _cardService;
     private readonly Stripe.BankAccountService _bankAccountService;
+    private readonly Stripe.PlanService _planService;
     private readonly Stripe.PriceService _priceService;
     private readonly Stripe.SetupIntentService _setupIntentService;
     private readonly Stripe.TestHelpers.TestClockService _testClockService;
@@ -33,6 +34,7 @@ public class StripeAdapter : IStripeAdapter
         _cardService = new Stripe.CardService();
         _bankAccountService = new Stripe.BankAccountService();
         _priceService = new Stripe.PriceService();
+        _planService = new Stripe.PlanService();
         _setupIntentService = new SetupIntentService();
         _testClockService = new Stripe.TestHelpers.TestClockService();
         _customerBalanceTransactionService = new CustomerBalanceTransactionService();
@@ -133,6 +135,11 @@ public class StripeAdapter : IStripeAdapter
         return invoices;
     }
 
+    public Task<Invoice> InvoiceCreatePreviewAsync(InvoiceCreatePreviewOptions options)
+    {
+        return _invoiceService.CreatePreviewAsync(options);
+    }
+
     public async Task<List<Stripe.Invoice>> InvoiceSearchAsync(InvoiceSearchOptions options)
         => (await _invoiceService.SearchAsync(options)).Data;
 
@@ -184,6 +191,11 @@ public class StripeAdapter : IStripeAdapter
         return _paymentMethodService.DetachAsync(id, options);
     }
 
+    public Task<Stripe.Plan> PlanGetAsync(string id, Stripe.PlanGetOptions options = null)
+    {
+        return _planService.GetAsync(id, options);
+    }
+
     public Task<Stripe.TaxRate> TaxRateCreateAsync(Stripe.TaxRateCreateOptions options)
     {
         return _taxRateService.CreateAsync(options);

src/Core/Services/Implementations/StripePaymentService.cs

@@ -1,7 +1,10 @@
 using Bit.Core.AdminConsole.Entities;
 using Bit.Core.AdminConsole.Entities.Provider;
 using Bit.Core.Billing.Constants;
+using Bit.Core.Billing.Extensions;
 using Bit.Core.Billing.Models;
+using Bit.Core.Billing.Models.Api.Requests.Accounts;
+using Bit.Core.Billing.Models.Api.Responses;
 using Bit.Core.Billing.Models.Business;
 using Bit.Core.Billing.Services;
 using Bit.Core.Entities;
@@ -1879,6 +1882,86 @@ public class StripePaymentService : IPaymentService
         }
     }
 
+    public async Task<PreviewInvoiceResponseModel> PreviewInvoiceAsync(PreviewInvoiceRequestBody parameters)
+    {
+        var pmStripePlan = await _stripeAdapter.PlanGetAsync("premium-annually");
+        var storageStripePlan = await _stripeAdapter.PlanGetAsync("storage-gb-annually");
+
+        var options = new InvoiceCreatePreviewOptions
+        {
+            AutomaticTax = new InvoiceAutomaticTaxOptions
+            {
+                Enabled = true,
+            },
+            Currency = "usd",
+            InvoiceItems = new List<InvoiceUpcomingInvoiceItemOptions>
+            {
+                new()
+                {
+                    Quantity = 1,
+                    PriceData = new InvoiceItemPriceDataOptions
+                    {
+                        Currency = "usd",
+                        UnitAmount = pmStripePlan.Amount,
+                        Product = pmStripePlan.ProductId
+                    }
+                },
+                new()
+                {
+                    Quantity = parameters.PasswordManager.AdditionalStorage,
+                    PriceData = new InvoiceItemPriceDataOptions
+                    {
+                        Currency = "usd",
+                        UnitAmount = storageStripePlan.Amount,
+                        Product = storageStripePlan.ProductId
+                    }
+                }
+            },
+            CustomerDetails = new InvoiceCustomerDetailsOptions
+            {
+                Address = new AddressOptions
+                {
+                    PostalCode = parameters.TaxInformation.PostalCode,
+                    Country = parameters.TaxInformation.Country,
+                }
+            },
+        };
+
+        if (parameters.TaxInformation.TaxId != null)
+        {
+            var taxIdType = _taxService.GetStripeTaxCode(
+                options.CustomerDetails.Address.Country,
+                parameters.TaxInformation.TaxId);
+
+            if (taxIdType != null)
+            {
+                options.CustomerDetails.TaxIds = [
+                    new InvoiceCustomerDetailsTaxIdOptions
+                    {
+                        Type = taxIdType,
+                        Value = parameters.TaxInformation.TaxId
+                    }
+                ];
+            }
+        }
+
+        var invoice = await _stripeAdapter.InvoiceCreatePreviewAsync(options);
+
+        decimal effectiveTaxRate = 0;
+
+        if (invoice.Tax != null && invoice.TotalExcludingTax != null)
+        {
+            effectiveTaxRate = invoice.Tax.Value.ToMajor() / invoice.TotalExcludingTax.Value.ToMajor();
+        }
+
+        var result = new PreviewInvoiceResponseModel(
+            effectiveTaxRate,
+            invoice.TotalExcludingTax.ToMajor() ?? 0,
+            invoice.Tax.ToMajor() ?? 0,
+            invoice.Total.ToMajor());
+        return result;
+    }
+
     private PaymentMethod GetLatestCardPaymentMethod(string customerId)
     {
         var cardPaymentMethods = _stripeAdapter.PaymentMethodListAutoPaging(