Program.cs

// NOTE: In order for the example to work you need to
// override the following configuration:
// contractingWorks:clientId - The identifier of the Contracting Works client you to interact with
// contractingWorks:subjectId - The identifier of the user used to interact with Contracting Works 
// contractingWorks:apiKey - The api key used to authentaticate the user above

// Loads the necessary configuration settings from various sources.
// It's recommended to inject these settings using user secrets in Visual Studio.
// The configuration includes client ID, subject ID, API key, and endpoints.
var configuration = new ConfigurationBuilder()
 .AddJsonFile("appsettings.json", true, true)
 .AddUserSecrets<MainApp>(optional: true)
 .AddEnvironmentVariables()
 .Build();

// Extract configuration values for different components.
// These values will be used to set up API connections.
var clientId = configuration.GetValue<string>("contractingWorks:clientId");
var subjectId = configuration.GetValue<string>("contractingWorks:subjectId");
var apiKey = configuration.GetValue<string>("contractingWorks:apiKey");
var authenticationHost = configuration.GetValue<string>("contractingWorks:authenticationHost");
var graphQlHost = configuration.GetValue<string>("contractingWorks:graphQlHost");
var restHost = configuration.GetValue<string>("contractingWorks:restHost");

// Construct base URLs for different endpoints.
// These URLs will be used as a foundation for constructing API requests.
var authenticationBaseUrl = $"https://{authenticationHost}/";
var graphQlBaseUrl = $"https://{graphQlHost}/client/{clientId}/graphql";
var restBaseUrl = $"https://{restHost}";

// Set up the HttpClient for making API requests.
// Configuration includes automatic decompression and a timeout.
var httpMessageHandler = new SocketsHttpHandler()
{
 AutomaticDecompression = DecompressionMethods.All,
};
using var httpClient = new HttpClient(httpMessageHandler)
{
 Timeout = TimeSpan.FromSeconds(170),
};

// Initialize the authentication client to obtain an access token.
var authClient = new DevincoConnectClient(authenticationBaseUrl, httpClient);

// Call the authentication API to get an access token for interacting with other APIs.
var authenticationResponse = await authClient.TokenGenerateAccessTokenAsJsonAsync(
 new()
 {
 ApiKey = apiKey,
 ClientId = 1,
 SubjectId = subjectId,
 TenantId = clientId,
 });
// cwToken is now the token used to interact with the graphQL and restAPI
// Note the token is valid for 1 hour
var cwToken = authenticationResponse.AccessToken;

// Set up dependency injection using the Host class.
var builder = Host.CreateApplicationBuilder(args);

// Add the HttpClient as a singleton service for efficient HTTP requests.
builder.Services.AddSingleton(httpClient);

// Set up the CW GQL Client (generated by Strawberry Shake) using dependency injection.
builder.Services
 .AddCWGQLClient()
 .ConfigureHttpClient(client => 
 {
 client.BaseAddress = new(graphQlBaseUrl);
 client.DefaultRequestHeaders.Authorization = new("Bearer", cwToken);
 });

// Add the MainApp class as a singleton service.
builder.Services.AddSingleton<MainApp>();

// Build the host using the configured services.
using var host = builder.Build();

var mainApp = host.Services.GetRequiredService<MainApp>();
// Run main app
await mainApp.Run(cwToken, clientId??"<Unknown>", restBaseUrl);

// The MainApp class encapsulates the core functionality of the example.
class MainApp
{
 readonly ILogger<MainApp> _logger;
 readonly CWGQLClient _graphQl;
 readonly HttpClient _httpClient;

 // Constructor injects necessary services for GraphQL and HTTP interactions.
 public MainApp(
 ILogger<MainApp> logger,
 CWGQLClient graphQl,
 HttpClient httpClient)
 {
 _logger = logger;
 _graphQl = graphQl;
 _httpClient = httpClient;
 }

 // The Run method performs the main functionality of the application.
 // It retrieves payment terms and customers using GraphQL,
 // updates payment terms for customers using REST API.
 public async Task Run(string cwToken, string clientId, string restBaseUrl)
 {
 // Give us the first 10 payment terms that are not deactivated (soft deleted)
 var paymentTermResponse = await _graphQl.GetPaymentTerm.ExecuteAsync(
 top:10, 
 filter:"sys_Deactivated = false");

 // Throws if there are any errors.
 paymentTermResponse.EnsureNoErrors();

 // Find the first payment term. Note that values might be null
 // so using ?. to avoid null reference exceptions is recommended
 var paymentTerm = paymentTermResponse.Data?.PaymentTerms?.Items?.FirstOrDefault();
 if (paymentTerm is null)
 {
 _logger.LogWarning($"No payment terms found :(");
 return;
 }

 var paymentTermDescription = paymentTerm?.Description??"No description";
 _logger.LogInformation($"Found payment term: {paymentTermDescription}");

 // Give us the first 10 customers that are not deactivated (soft deleted)
 var customerResponse = await _graphQl.GetCustomer.ExecuteAsync(
 top:10, 
 filter:"sys_Deactivated = false");

 // Throws if there are any errors.
 customerResponse.EnsureNoErrors();

 // Find the customers payload. Note that values might be null
 // so using ?. to avoid null reference exceptions is recommended
 var customers = customerResponse?.Data?.Customers?.Items;
 if (customers is null)
 {
 _logger.LogWarning($"No customers found :(");
 return;
 }

 // Print customer information using a loop.
 foreach (var customer in customers)
 {
 _logger.LogInformation($"Customer - {customer.CustomerNumber} - {customer.Name} - {customer.PaymentTerm?.Description??"No payment term"}");
 }

 _logger.LogInformation($"Do you want me to change the payment term of all the customers above to {paymentTermDescription}\nType YES if you do");

 // Prompt user for confirmation before making changes.
 var response = Console.ReadLine()??"";
 if (response != "YES")
 {
 _logger.LogInformation($"Ok I won't do anything then, bye!");
 return;
 }

 _logger.LogInformation($"Ok, updating payment terms of all customers");


 // Prepare an upsert request for changing payment terms of customers.
 var changedCustomers = new List<CustomerDto>();
 foreach (var customer in customers)
 {
 changedCustomers.Add(new ()
 {
 // CustomerId is the primary key of the Customer table
 // By setting this to a non-null value, it indicates that we want to
 // update an existing customer. If it is null, it signifies creating a new customer.
 CustomerId = customer.CustomerId,
 // Set the payment term foreign key of the customer to
 // the payment term id
 PaymentTermId = paymentTerm!.PaymentTermId
 });
 }

 // Initialize a REST client and perform the upsert operation.
 var restClient = new ContractingWorksClient(restBaseUrl, _httpClient)
 {
 CwToken = cwToken,
 Logger = _logger
 };
 var repsonse = await restClient.V3ClientCustomerUpsertAsync(clientId, null, 0, changedCustomers);

 _logger.LogInformation($"So, the customers are now updated");
 }
}