PaymentService.cs

using Stripe;
using hdl.Infrastructure.Interfaces;
using Microsoft.Extensions.Configuration;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;

namespace hdl.Infrastructure.Services
{
	public class PaymentService : IPayment
	{
        private readonly IConfiguration _config;
        public bool UseSandbox { get; set; }
		public string ApiKey
		{
			get;
			set;
		}

		public PaymentService(IConfiguration config)
		{
            _config = config;
			if (string.IsNullOrWhiteSpace(ApiKey))
			{
				var env = System.Environment.GetEnvironmentVariable("ASPNETCORE_ENVIRONMENT");

				if (env.Equals("Production", StringComparison.CurrentCultureIgnoreCase))
				{
					ApiKey = System.Environment.GetEnvironmentVariable("StripeConfig:ApiKey");
				}
                else if (env.Equals("Testing", StringComparison.CurrentCultureIgnoreCase))
                {
                    ApiKey = System.Environment.GetEnvironmentVariable("TestStripeConfig:ApiKey");
                    UseSandbox = true;
                }
				else
				{
					ApiKey = config["StripeConfig:ApiKey"];
                    UseSandbox = true;
				}
                StripeConfiguration.ApiKey = ApiKey;
			}
		}
        public async Task<PaymentIntent> CreatePaymentIntent(long amount, string gamertag, string email)
        {
            var options = new PaymentIntentCreateOptions
            {
                Amount = amount * 100,
                Currency = "usd",
                ReceiptEmail = email,
                Description = $"Event registration fee for {gamertag}",
                Metadata = UseSandbox ?
                    new Dictionary<string, string>
                    {
                        { "integration_check", "accept_a_payment" }
                    }
                    : null
            };
            var service = new PaymentIntentService();
            return await service.CreateAsync(options);
        }
	}
}