server/src/Billing/Controllers/PaypalController.cs

using Bit.Billing.Utilities;
using Bit.Core.Enums;
using Bit.Core.Repositories;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Options;
using Newtonsoft.Json;
using System.IO;
using System.Text;
using System.Threading.Tasks;

namespace Bit.Billing.Controllers
{
    [Route("paypal")]
    public class PaypalController : Controller
    {
        private readonly BillingSettings _billingSettings;
        private readonly PaypalClient _paypalClient;
        private readonly ITransactionRepository _transactionRepository;

        public PaypalController(
            IOptions<BillingSettings> billingSettings,
            PaypalClient paypalClient,
            ITransactionRepository transactionRepository)
        {
            _billingSettings = billingSettings?.Value;
            _paypalClient = paypalClient;
            _transactionRepository = transactionRepository;
        }

        [HttpPost("webhook")]
        public async Task<IActionResult> PostWebhook([FromQuery] string key)
        {
            if(HttpContext?.Request == null)
            {
                return new BadRequestResult();
            }

            string body = null;
            using(var reader = new StreamReader(HttpContext.Request.Body, Encoding.UTF8))
            {
                body = await reader.ReadToEndAsync();
            }

            if(body == null)
            {
                return new BadRequestResult();
            }

            var verified = await _paypalClient.VerifyWebhookAsync(body, HttpContext.Request.Headers,
                _billingSettings.Paypal.WebhookId);
            if(!verified)
            {
                return new BadRequestResult();
            }

            if(body.Contains("\"PAYMENT.SALE.COMPLETED\""))
            {
                var ev = JsonConvert.DeserializeObject<PaypalClient.Event<PaypalClient.Sale>>(body);
                var sale = ev.Resource;
                var saleTransaction = await _transactionRepository.GetByGatewayIdAsync(
                    GatewayType.PayPal, sale.Id);
                if(saleTransaction == null)
                {
                    var ids = sale.GetIdsFromCustom();
                    if(ids.Item1.HasValue || ids.Item2.HasValue)
                    {
                        await _transactionRepository.CreateAsync(new Core.Models.Table.Transaction
                        {
                            Amount = sale.Amount.TotalAmount,
                            CreationDate = sale.CreateTime,
                            OrganizationId = ids.Item1,
                            UserId = ids.Item2,
                            Type = sale.GetCreditFromCustom() ? TransactionType.Credit : TransactionType.Charge,
                            Gateway = GatewayType.PayPal,
                            GatewayId = sale.Id,
                            PaymentMethodType = PaymentMethodType.PayPal
                        });
                    }
                }
            }
            else if(body.Contains("\"PAYMENT.SALE.REFUNDED\""))
            {
                var ev = JsonConvert.DeserializeObject<PaypalClient.Event<PaypalClient.Refund>>(body);
                var refund = ev.Resource;
                var refundTransaction = await _transactionRepository.GetByGatewayIdAsync(
                    GatewayType.PayPal, refund.Id);
                if(refundTransaction == null)
                {
                    var ids = refund.GetIdsFromCustom();
                    if(ids.Item1.HasValue || ids.Item2.HasValue)
                    {
                        await _transactionRepository.CreateAsync(new Core.Models.Table.Transaction
                        {
                            Amount = refund.Amount.TotalAmount,
                            CreationDate = refund.CreateTime,
                            OrganizationId = ids.Item1,
                            UserId = ids.Item2,
                            Type = TransactionType.Refund,
                            Gateway = GatewayType.PayPal,
                            GatewayId = refund.Id,
                            PaymentMethodType = PaymentMethodType.PayPal
                        });
                    }

                    var saleTransaction = await _transactionRepository.GetByGatewayIdAsync(
                        GatewayType.PayPal, refund.SaleId);
                    if(saleTransaction != null)
                    {
                        saleTransaction.Refunded = true;
                        saleTransaction.RefundedAmount = refund.TotalRefundedAmount.ValueAmount;
                        await _transactionRepository.ReplaceAsync(saleTransaction);
                    }
                }
            }

            return new OkResult();
        }
    }
}