social-media/backend/src/Web/Features/Memberships/Infrastructure/StripeService.cs

using System.ComponentModel.DataAnnotations;
using Hutopy.Web.Features.Memberships.Data;
using Hutopy.Web.Features.Memberships.Events;
using Microsoft.Extensions.Options;
using Stripe;
using Stripe.Checkout;
using Subscription = Stripe.Subscription;

namespace Hutopy.Web.Features.Memberships.Infrastructure;

public class StripeOptions
{
    [Required] public required string SecretKey { get; init; }

    [Required] public required string WebhookSecret { get; init; }

    [Required] [Range(0, 1)] public required decimal HutopyRate { get; init; }
}

public sealed class StripeService(
    IOptions<StripeOptions> paymentOptions,
    MembershipDbContext dbContext,
    PushNotificationService notificationService)
{
    public async Task<string> CreateProductAsync(
        Guid creatorId,
        Guid tierId,
        string productName,
        string currencyCode,
        decimal amount)
    {
        StripeConfiguration.ApiKey = paymentOptions.Value.SecretKey;

        // Create the product
        var productService = new ProductService();
        var product = await productService.CreateAsync(
            new ProductCreateOptions
            {
                Name = productName,
                Metadata = { { "creatorId", creatorId.ToString() }, { "tierId", tierId.ToString() } }
            });

        // Create the price for the product
        var priceService = new PriceService();
        await priceService.CreateAsync(
            new PriceCreateOptions
            {
                Product = product.Id,
                UnitAmountDecimal = amount * 100, // Convert amount to cents
                Currency = currencyCode,
                Recurring = new PriceRecurringOptions { Interval = "month" }
            });

        return product.Id;
    }

    public async Task<Session> CreateTipCheckoutSessionAsync(
        Guid creatorId,
        string creatorName,
        decimal amount,
        string currencyCode,
        string message,
        string creatorAccountId,
        string successUrl,
        string cancelUrl,
        CancellationToken ct = default)
    {
        StripeConfiguration.ApiKey = paymentOptions.Value.SecretKey;

        // Create Stripe customer for the user if not already created
        var customerService = new CustomerService();
        var customer = await customerService.CreateAsync(
            new CustomerCreateOptions{},
            cancellationToken: ct);

        // Create paymentIntent for the user
        var sessionService = new SessionService();
        return await sessionService.CreateAsync(
            new SessionCreateOptions
            {
                Customer = customer.Id,
                PaymentMethodTypes = ["card"],
                LineItems =
                [
                    new SessionLineItemOptions
                    {
                        PriceData = new SessionLineItemPriceDataOptions
                        {
                            Currency = currencyCode,
                            UnitAmountDecimal = amount, // Amount in cents
                            ProductData = new SessionLineItemPriceDataProductDataOptions
                            {
                                Name = $"Tip for {creatorName}", // or any descriptive name for the tip
                                Metadata = new Dictionary<string, string> { { "creatorId", creatorId.ToString() } }
                            }
                        },
                        Quantity = 1
                    }
                ],
                Mode = "payment",
                PaymentIntentData = new SessionPaymentIntentDataOptions
                {
                    ApplicationFeeAmount =
                        Convert.ToInt64(amount * 100 * paymentOptions.Value.HutopyRate), // Platform fee
                    TransferData = new SessionPaymentIntentDataTransferDataOptions
                    {
                        Destination = creatorAccountId // Creator's Stripe account ID
                    }
                },
                SuccessUrl = successUrl, // Redirect after successful payment
                CancelUrl = cancelUrl, // Redirect after canceled payment
                Metadata = new Dictionary<string, string>
                {
                    { "creatorId", creatorId.ToString() },
                    { "creatorName", creatorName },
                    { "message", message },
                }
            },
            cancellationToken: ct);
    }

    public async Task<Session> CreateSubscriptionCheckoutSession(
        Guid userId,
        Guid creatorId,
        string creatorName,
        string creatorAccountId,
        Guid tierId,
        string priceId,
        string successUrl,
        string cancelUrl)
    {
        StripeConfiguration.ApiKey = paymentOptions.Value.SecretKey;

        // Create Stripe customer for the user if not already created
        var customerService = new CustomerService();
        var customer = await customerService.CreateAsync(
            new CustomerCreateOptions
            {
                Metadata = new Dictionary<string, string> { { "userId", userId.ToString() } }
            });

        // Create Checkout Session for the subscription
        var sessionService = new SessionService();
        return await sessionService.CreateAsync(
            new SessionCreateOptions
            {
                Customer = customer.Id,
                PaymentMethodTypes = ["card"],
                LineItems =
                [
                    new SessionLineItemOptions { Price = priceId, Quantity = 1 }
                ],
                Mode = "subscription",
                SubscriptionData = new SessionSubscriptionDataOptions
                {
                    ApplicationFeePercent = paymentOptions.Value.HutopyRate,
                    TransferData = new SessionSubscriptionDataTransferDataOptions { Destination = creatorAccountId }
                },
                SuccessUrl = successUrl, // Redirect after successful payment
                CancelUrl = cancelUrl, // Redirect after canceled payment
                Metadata = new Dictionary<string, string>
                {
                    { "userId", userId.ToString() },
                    { "creatorId", creatorId.ToString() },
                    { "creatorName", creatorName },
                    { "tierId", tierId.ToString() }
                }
            });
    }

    public async Task CancelSubscription(
        Guid subscriptionId)
    {
        var subscriptionService = new SubscriptionService();
        await subscriptionService.CancelAsync(subscriptionId.ToString());
    }

    public async Task HandleInvoicePaymentSucceeded(
        Event stripeEvent,
        CancellationToken ct = default)
    {
        // Ensure we have an invoice related to a Subscription
        if (stripeEvent.Data.Object is not Invoice { Subscription: not null } invoice)
        {
            return;
        }

        var subscription = await dbContext
            .Subscriptions
            .FirstOrDefaultAsync(
                subscription => subscription.StripeSubscriptionId == invoice.Subscription.Id,
                cancellationToken: ct);

        if (subscription == null)
        {
            return;
        }

        // Record the Transaction
        var transaction = new Transaction
        {
            Id = Guid.NewGuid(),
            CreatedAt = DateTimeOffset.UtcNow,
            Amount = invoice.AmountPaid / 100m, // Convert amount from cents to dollars
            Currency = invoice.Currency,
            Type = "Subscription",
            Timestamp = DateTime.UtcNow,
            StripeInvoiceUrl = invoice.HostedInvoiceUrl
        };

        dbContext.Transactions.Add(transaction);

        // Link the Transaction to the Subscription
        subscription.Transactions.Add(transaction);

        await dbContext.SaveChangesAsync(ct);
    }

    public async Task HandleInvoicePaymentFailed(
        Event stripeEvent,
        CancellationToken ct = default)
    {
        if (stripeEvent.Data.Object is not Invoice { Subscription: not null } invoice)
        {
            return;
        }

        var subscription = await dbContext
            .Subscriptions
            .SingleOrDefaultAsync(
                subscription => subscription.StripeSubscriptionId == invoice.SubscriptionId,
                cancellationToken: ct);

        if (subscription != null)
        {
            subscription.EndDate = DateTimeOffset.UtcNow; // Mark as expired or failed
            await dbContext.SaveChangesAsync(ct);
        }
    }

    private async Task HandleTipPayment(
        Session session,
        CancellationToken ct)
    {
        // Record the Tip
        var tip = new Tip
        {
            Id = Guid.NewGuid(),
            CreatedAt = DateTimeOffset.UtcNow,
            StripeSessionId = session.Id,
            TipperId = Guid.Parse(session.Metadata["tipperId"]),
            TipperName = session.Metadata["tipperName"],
            CreatorId = Guid.Parse(session.Metadata["creatorId"]),
            CreatorName = session.Metadata["creatorName"],
            Amount = session.AmountTotal!.Value / 100m,
            Currency = session.Currency,
            Message = session.Metadata["message"]
        };

        dbContext.Tips.Add(tip);

        // Record the Transaction
        var transaction = new Transaction
        {
            Id = Guid.NewGuid(),
            CreatedAt = DateTimeOffset.UtcNow,
            Amount = tip.Amount,
            Currency = tip.Currency,
            Type = "Tip",
            Timestamp = DateTime.UtcNow,
            // TODO: __StripeInvoiceUrl = session.Invoice.HostedInvoiceUrl__  How come nor Invoice or InvoiceId are set.
        };

        dbContext.Transactions.Add(transaction);

        // Link the Transaction to the Tip
        tip.TransactionId = transaction.Id;

        // Save the changes
        await dbContext.SaveChangesAsync(ct);

        // Notify the Creator
        notificationService.NotifyCreator(
            tip.CreatorId,
            new TipPaid(
                tip.CreatorId,
                tip.CreatorName,
                tip.Amount,
                tip.Currency,
                tip.Message)
        );
    }

    private async Task HandleSubscriptionPayment(
        Session session,
        CancellationToken ct)
    {
        // Record the Subscription
        var subscription = new Data.Subscription
        {
            Id = Guid.NewGuid(),
            CreatedAt = DateTimeOffset.UtcNow,
            UserId = Guid.Parse(session.Metadata["userId"]),
            CreatorId = Guid.Parse(session.Metadata["creatorId"]),
            TierId = Guid.Parse(session.Metadata["tierId"]),
            StartDate = DateTimeOffset.UtcNow,
            StripeSessionId = session.Id,
            StripeSubscriptionId = session.SubscriptionId
        };

        dbContext.Subscriptions.Add(subscription);

        // Record the Transaction
        var transaction = new Transaction
        {
            Id = Guid.NewGuid(),
            CreatedAt = DateTimeOffset.UtcNow,
            Amount = session.AmountTotal!.Value / 100m, // Convert amount from cents to dollars
            Currency = session.Currency,
            Type = "Subscription",
            Timestamp = DateTime.UtcNow,
            // TODO: __StripeInvoiceUrl = session.Invoice.HostedInvoiceUrl__  How come nor Invoice or InvoiceId are set.
        };

        dbContext.Transactions.Add(transaction);

        // Link the Transaction to the Subscription
        subscription.Transactions.Add(transaction);

        // Save the changes
        await dbContext.SaveChangesAsync(ct);

        // Notify the Creator
        notificationService.NotifyCreator(
            subscription.CreatorId,
            new SubscriptionPaid(
                subscription.CreatorId,
                session.Metadata["creatorName"],
                subscription.TierId.ToString(),
                subscription.StartDate)
        );
    }

    public async Task HandleCheckoutSessionCompleted(
        Event stripeEvent,
        CancellationToken ct = default)
    {
        if (stripeEvent.Data.Object is not Session session)
        {
            return;
        }

        switch (session.Mode)
        {
            // Check if this is a one-time tip
            case "payment" when session.PaymentIntentId != null:
                await HandleTipPayment(session, ct);
                break;
            // Check if this is a subscription
            case "subscription" when session.SubscriptionId != null:
                await HandleSubscriptionPayment(session, ct);
                break;
        }
    }

    public async Task HandleCustomerSubscriptionCreated(
        Event stripeEvent,
        CancellationToken ct)
    {
        if (stripeEvent.Data.Object is not Subscription stripeSubscription)
            return;

        var subscription = await dbContext
            .Subscriptions
            .SingleOrDefaultAsync(
                subscription => subscription.StripeSubscriptionId == stripeSubscription.Id,
                cancellationToken: ct);

        if (subscription != null)
        {
            subscription.StartDate = stripeSubscription.CurrentPeriodStart;
            subscription.EndDate = null; // Active subscription

            await dbContext.SaveChangesAsync(ct);
        }
    }

    public async Task HandleCustomerSubscriptionUpdated(
        Event stripeEvent,
        CancellationToken ct)
    {
        if (stripeEvent.Data.Object is Subscription stripeSubscription)
        {
            var subscription = await dbContext
                .Subscriptions
                .SingleOrDefaultAsync(
                    s => s.StripeSubscriptionId == stripeSubscription.Id,
                    cancellationToken: ct);

            if (subscription != null)
            {
                subscription.StartDate = stripeSubscription.CurrentPeriodStart;
                subscription.EndDate = null; // Active subscription

                await dbContext.SaveChangesAsync(ct);
            }
        }
    }

    public async Task HandleCustomerSubscriptionDeleted(
        Event stripeEvent,
        CancellationToken ct)
    {
        var subscription = stripeEvent.Data.Object as Subscription;
        var existingSubscription = await dbContext
            .Subscriptions
            .FirstOrDefaultAsync(x => x.StripeSubscriptionId == subscription!.Id, ct);

        if (existingSubscription != null)
        {
            var today = DateTime.Today;
            int lastDay = DateTime.DaysInMonth(today.Year, today.Month);
            var lastDayOfMonth = new DateTime(today.Year, today.Month, lastDay);
            existingSubscription.EndDate = new DateTimeOffset(lastDayOfMonth);
            await dbContext.SaveChangesAsync(ct);
        }
    }
}