using System;

using System.Threading.Tasks;

using GraphQL;

using GraphQL.Client.Http;

using GraphQL.Client.Serializer.Newtonsoft;

using System.Text.Json;

public class Program

{

    // Define full mutation for payment request.

    private const string CreatePaymentRequestMutation = @"mutation CreatePaymentRequest(

        $amount: MoneyInput!,

        $payerReference: String!,

        $beneficiaryReference: String!,

        $externalReference: String,

        $beneficiaryName: String!,

        $beneficiaryBankId: BankBeneficiaryBankId!,

        $beneficiaryAccountNumber: String!,

        $merchant: String!,

        $expireAt: Date) {

      clientPaymentInitiationRequestCreate(input: {

          amount: $amount,

          payerReference: $payerReference,

          beneficiaryReference: $beneficiaryReference,

          externalReference: $externalReference,

          beneficiary: {

              bankAccount: {

                  name: $beneficiaryName,

                  bankId: $beneficiaryBankId,

                  accountNumber: $beneficiaryAccountNumber

              }

          },

          merchant: $merchant,

          expireAt: $expireAt

        }) {

        paymentInitiationRequest {

          id

          url

        }

      }

    }";

    // Define response object that will be returned within the `Data` object in the GraphQL response.

    public class CreateAuthRequestResponse {

        public ClientPaymentInitiationRequestCreate clientPaymentInitiationRequestCreate { get; set; }

        public class ClientPaymentInitiationRequestCreate

        {

            public PaymentInitiationRequest paymentInitiationRequest { get; set; }

        }

        public class PaymentInitiationRequest

        {

            public string id { get; set; }

            public string url { get; set; }

        }

    }

    public static async Task Main()

    {

        // Initialize GraphQL client.

        var graphQLClient = new GraphQLHttpClient("https://api.stitch.money/graphql", new NewtonsoftJsonSerializer());

        // Set client token in bearer auth (created by authentication call).

        var token = "{{ add client access token }}";

        graphQLClient.HttpClient.DefaultRequestHeaders.Add("Authorization", $"Bearer {token}");

        // Create GraphQL request with defined query, and input parameters (declared as per mutation).

        var request = new GraphQLRequest

        {

            Query = CreatePaymentRequestMutation, 

            Variables = new 

            {

                amount = new

                {

                    quantity = 50,

                    currency = "ZAR",

                },

                payerReference = "KombuchaFizz",

                beneficiaryReference = "Joe-Fizz-01",

                externalReference = "externalReference01",

                beneficiaryName = "FizzBuzz Co.",

                beneficiaryBankId = "fnb",

                beneficiaryAccountNumber = "123456789", 

                // Stringified-JSON field related to particular merchant this payment is for.

                merchant = "{ merchantId: '123', merchantName: 'Acme Inc' }",

                expireAt = DateTime.UtcNow.AddMinutes(20)

            },

        };

        // Call client specfying expected response type.

        var response = await graphQLClient.SendMutationAsync<CreateAuthRequestResponse>(request);

        Console.WriteLine("Raw response:");

        Console.WriteLine(JsonSerializer.Serialize(response, new JsonSerializerOptions { WriteIndented = true }));

        // Build up full payment request URL to surface to user by appending redirect URI.

        Console.WriteLine();

        Console.WriteLine($"Payment Request URL: {response.Data.clientPaymentInitiationRequestCreate.paymentInitiationRequest.url}?redirect_uri=https://localhost:8080/return");

    }

}