[PM-29598] Create Subscription Upgrade Endpoint

src/Api/Billing/Controllers/VNext/AccountBillingVNextController.cs

@@ -23,7 +23,8 @@ public class AccountBillingVNextController(
     IGetCreditQuery getCreditQuery,
     IGetPaymentMethodQuery getPaymentMethodQuery,
     IGetUserLicenseQuery getUserLicenseQuery,
-    IUpdatePaymentMethodCommand updatePaymentMethodCommand) : BaseBillingController
+    IUpdatePaymentMethodCommand updatePaymentMethodCommand,
+    IUpgradePremiumToOrganizationCommand upgradePremiumToOrganizationCommand) : BaseBillingController
 {
     [HttpGet("credit")]
     [InjectUser]
@@ -88,4 +89,16 @@ public async Task<IResult> GetLicenseAsync(
         var response = await getUserLicenseQuery.Run(user);
         return TypedResults.Ok(response);
     }
+
+    [HttpPost("upgrade")]
+    [InjectUser]
+    public async Task<IResult> UpgradePremiumToOrganizationAsync(
+        [BindNever] User user,
+        [FromBody] UpgradePremiumToOrganizationRequest request)
+    {
+        var (planType, seats, premiumAccess, storage, trialEndDate) = request.ToDomain();
+        var result = await upgradePremiumToOrganizationCommand.Run(
+            user, planType, seats, premiumAccess, storage, trialEndDate);
+        return Handle(result);
+    }
 }

src/Api/Billing/Models/Requests/Premium/UpgradePremiumToOrganizationRequest.cs

@@ -0,0 +1,23 @@
+using System.ComponentModel.DataAnnotations;
+using Bit.Core.Billing.Enums;
+
+namespace Bit.Api.Billing.Models.Requests.Premium;
+
+public class UpgradePremiumToOrganizationRequest
+{
+    [Required]
+    public required PlanType PlanType { get; set; }
+
+    [Range(1, int.MaxValue)]
+    public int Seats { get; set; }
+
+    public bool PremiumAccess { get; set; } = false;
+
+    [Range(0, 99)]
+    public int Storage { get; set; } = 0;
+
+    public DateTime? TrialEndDate { get; set; }
+
+    public (PlanType, int, bool, int?, DateTime?) ToDomain() =>
+        (PlanType, Seats, PremiumAccess, Storage > 0 ? Storage : null, TrialEndDate);
+}

src/Core/Billing/Extensions/ServiceCollectionExtensions.cs

@@ -53,6 +53,7 @@ private static void AddPremiumCommands(this IServiceCollection services)
         services.AddScoped<ICreatePremiumCloudHostedSubscriptionCommand, CreatePremiumCloudHostedSubscriptionCommand>();
         services.AddScoped<ICreatePremiumSelfHostedSubscriptionCommand, CreatePremiumSelfHostedSubscriptionCommand>();
         services.AddTransient<IPreviewPremiumTaxCommand, PreviewPremiumTaxCommand>();
+        services.AddScoped<IUpgradePremiumToOrganizationCommand, UpgradePremiumToOrganizationCommand>();
     }
 
     private static void AddPremiumQueries(this IServiceCollection services)

src/Core/Billing/Premium/Commands/UpgradePremiumToOrganizationCommand.cs

@@ -0,0 +1,173 @@
+using Bit.Core.Billing.Commands;
+using Bit.Core.Billing.Constants;
+using Bit.Core.Billing.Enums;
+using Bit.Core.Billing.Extensions;
+using Bit.Core.Billing.Pricing;
+using Bit.Core.Billing.Services;
+using Bit.Core.Entities;
+using Bit.Core.Services;
+using Microsoft.Extensions.Logging;
+using OneOf.Types;
+using Stripe;
+
+namespace Bit.Core.Billing.Premium.Commands;
+/// <summary>
+/// Upgrades a user's Premium subscription to an Organization plan by modifying the existing Stripe subscription.
+/// </summary>
+public interface IUpgradePremiumToOrganizationCommand
+{
+    /// <summary>
+    /// Upgrades a Premium subscription to an Organization subscription.
+    /// </summary>
+    /// <param name="user">The user with an active Premium subscription to upgrade.</param>
+    /// <param name="targetPlanType">The target organization plan type to upgrade to.</param>
+    /// <param name="seats">The number of seats for the organization plan.</param>
+    /// <param name="premiumAccess">Whether to include premium access for the organization.</param>
+    /// <param name="storage">Additional storage in GB for the organization.</param>
+    /// <param name="trialEndDate">The trial end date to apply to the upgraded subscription.</param>
+    /// <returns>A billing command result indicating success or failure with appropriate error details.</returns>
+    Task<BillingCommandResult<None>> Run(
+        User user,
+        PlanType targetPlanType,
+        int seats,
+        bool premiumAccess,
+        int? storage,
+        DateTime? trialEndDate);
+}
+
+public class UpgradePremiumToOrganizationCommand(
+    ILogger<UpgradePremiumToOrganizationCommand> logger,
+    IPricingClient pricingClient,
+    IStripeAdapter stripeAdapter,
+    ISubscriberService subscriberService,
+    IUserService userService)
+    : BaseBillingCommand<UpgradePremiumToOrganizationCommand>(logger), IUpgradePremiumToOrganizationCommand
+{
+    public Task<BillingCommandResult<None>> Run(
+        User user,
+        PlanType targetPlanType,
+        int seats,
+        bool premiumAccess,
+        int? storage,
+        DateTime? trialEndDate) => HandleAsync<None>(async () =>
+    {
+        // Validate that the user has an active Premium subscription
+        if (!user.Premium)
+        {
+            return new BadRequest("User does not have an active Premium subscription.");
+        }
+
+        if (string.IsNullOrEmpty(user.GatewaySubscriptionId))
+        {
+            return new BadRequest("User does not have a Stripe subscription.");
+        }
+
+        if (seats < 1)
+        {
+            return new BadRequest("Seats must be at least 1.");
+        }
+
+        if (trialEndDate.HasValue && trialEndDate.Value < DateTime.UtcNow)
+        {
+            return new BadRequest("Trial end date cannot be in the past.");
+        }
+
+        // Fetch the current Premium subscription from Stripe
+        var currentSubscription = await subscriberService.GetSubscriptionOrThrow(user, new SubscriptionGetOptions
+        {
+            Expand = ["items.data.price"]
+        });
+
+        // Get the target organization plan
+        var targetPlan = await pricingClient.GetPlanOrThrow(targetPlanType);
+
+        // Validate plan supports requested features
+        if (premiumAccess && string.IsNullOrEmpty(targetPlan.PasswordManager.StripePremiumAccessPlanId))
+        {
+            return new BadRequest("The selected plan does not support premium access.");
+        }
+
+        if (storage is > 0 && string.IsNullOrEmpty(targetPlan.PasswordManager.StripeStoragePlanId))
+        {
+            return new BadRequest("The selected plan does not support additional storage.");
+        }
+
+        // Build the list of subscription item updates
+        var subscriptionItemOptions = new List<SubscriptionItemOptions>();
+
+        // Mark existing Premium subscription items for deletion
+        foreach (var item in currentSubscription.Items.Data)
+        {
+            subscriptionItemOptions.Add(new SubscriptionItemOptions
+            {
+                Id = item.Id,
+                Deleted = true
+            });
+        }
+
+        // Add new organization subscription items
+        if (targetPlan.HasNonSeatBasedPasswordManagerPlan())
+        {
+            subscriptionItemOptions.Add(new SubscriptionItemOptions
+            {
+                Price = targetPlan.PasswordManager.StripePlanId,
+                Quantity = 1
+            });
+        }
+        else
+        {
+            subscriptionItemOptions.Add(new SubscriptionItemOptions
+            {
+                Price = targetPlan.PasswordManager.StripeSeatPlanId,
+                Quantity = seats
+            });
+        }
+
+        if (premiumAccess)
+        {
+            subscriptionItemOptions.Add(new SubscriptionItemOptions
+            {
+                Price = targetPlan.PasswordManager.StripePremiumAccessPlanId,
+                Quantity = 1
+            });
+        }
+
+        if (storage is > 0)
+        {
+            subscriptionItemOptions.Add(new SubscriptionItemOptions
+            {
+                Price = targetPlan.PasswordManager.StripeStoragePlanId,
+                Quantity = storage
+            });
+        }
+
+        // Build the subscription update options
+        var subscriptionUpdateOptions = new SubscriptionUpdateOptions
+        {
+            Items = subscriptionItemOptions,
+            ProrationBehavior = StripeConstants.ProrationBehavior.None,
+            Metadata = new Dictionary<string, string>(currentSubscription.Metadata ?? new Dictionary<string, string>())
+            {
+                ["premium_upgrade_metadata"] = currentSubscription.Items.Data
+                    .Select(item => item.Price.Id)
+                    .FirstOrDefault() ?? "premium"
+            }
+        };
+
+        // Apply trial period if specified
+        if (trialEndDate.HasValue)
+        {
+            subscriptionUpdateOptions.TrialEnd = trialEndDate.Value;
+        }
+
+        // Update the subscription in Stripe
+        await stripeAdapter.UpdateSubscriptionAsync(currentSubscription.Id, subscriptionUpdateOptions);
+
+        // Update user record
+        user.PremiumExpirationDate = trialEndDate ?? currentSubscription.GetCurrentPeriodEnd();
+        user.RevisionDate = DateTime.UtcNow;
+        await userService.SaveUserAsync(user);
+
+        return new None();
+    });
+}

test/Api.Test/Billing/Controllers/VNext/AccountBillingVNextControllerTests.cs

@@ -19,6 +19,7 @@ public class AccountBillingVNextControllerTests
     private readonly IGetPaymentMethodQuery _getPaymentMethodQuery;
     private readonly IGetUserLicenseQuery _getUserLicenseQuery;
     private readonly IUpdatePaymentMethodCommand _updatePaymentMethodCommand;
+    private readonly IUpgradePremiumToOrganizationCommand _upgradePremiumToOrganizationCommand;
     private readonly AccountBillingVNextController _sut;
 
     public AccountBillingVNextControllerTests()
@@ -29,14 +30,16 @@ public AccountBillingVNextControllerTests()
         _getPaymentMethodQuery = Substitute.For<IGetPaymentMethodQuery>();
         _getUserLicenseQuery = Substitute.For<IGetUserLicenseQuery>();
         _updatePaymentMethodCommand = Substitute.For<IUpdatePaymentMethodCommand>();
+        _upgradePremiumToOrganizationCommand = Substitute.For<IUpgradePremiumToOrganizationCommand>();
 
         _sut = new AccountBillingVNextController(
             _createBitPayInvoiceForCreditCommand,
             _createPremiumCloudHostedSubscriptionCommand,
             _getCreditQuery,
             _getPaymentMethodQuery,
             _getUserLicenseQuery,
-            _updatePaymentMethodCommand);
+            _updatePaymentMethodCommand,
+            _upgradePremiumToOrganizationCommand);
     }
 
     [Theory, BitAutoData]