// We assume `Configuration` is a IConfiguration instance containing the settings from eg. appsettings.json.

var maskinportenSettings = new MaskinportenSettings();
Configuration.GetSection("MaskinportenSettings").Bind(maskinportenSettings);

// Named client
services.AddMaskinportenHttpClient<SettingsJwkClientDefinition>("myhttpclient", maskinportenSettings);

// For convenience you can pass the IConfiguration instance directly
// services.AddMaskinportenHttpClient<SettingsJwkClientDefinition>("myhttpclient", Configuration.GetSection("MaskinportenSettings"));

// Typed client (MyMaskinportenHttpClient is any class accepting a HttpClient paramter in its constructor)
services.AddMaskinportenHttpClient<SettingsJwkClientDefinition, MyMaskinportenHttpClient>(maskinportenSettings); 

// Another typed client, using the same app settings, but overriding the setting for Altinn token exchange
services.AddMaskinportenHttpClient<SettingsJwkClientDefinition, MyMaskinportenHttpClient>(
  maskinportenSettings, clientDefinition =>
{
    clientDefinition.ClientSettings.ExhangeToAltinnToken = true;
});

// You can chain additional handlers or configure the client if required 
services.AddMaskinportenHttpClient<SettingsJwkClientDefinition, MyMaskinportenHttpClient>(maskinportenSettings)
    .AddHttpMessageHandler(sp => ...)
    .ConfigureHttpClient(client => ...)
            
// Registering av Maskinporten-powered client without adding it to HttpClientFactory / DIC
services.RegisterMaskinportenClientDefinition<SettingsJwkClientDefinition>(
  "my-client-definition-instance-key",
  maskinportenSettings);

// This can then be added as a HttpMessageHandler to any IClientBuilder. This is
// useful if you're already using a client builder (DAN, Polly, Refit etc).
services.AddHttpClient<MyMaskinportenHttpClient>()
    .AddMaskinportenHttpMessageHandler<SettingsJwkClientDefinition>("my-client-definition-instance-key");

// The Maskinporten-enabled client can then be utilized like any other HttpClient via HttpClientFactory, eg DI-ed in a controller like this:
public class MyController : ControllerBase
{
    private readonly IHttpClientFactory _clientFactory;
    private readonly MyMaskinportenHttpClient _myMaskinportenHttpClient;

    public MyController(
        IHttpClientFactory clientFactory, MyMaskinportenHttpClient myMaskinportenHttpClient)
     {
        _clientFactory = clientFactory;
        _myMaskinportenHttpClient = myMaskinportenHttpClient;
     }

    [HttpGet]
    public async Task<string> Get()
    {
       // Here we use the named client we configured earlier
       var myclient = _clientFactory.CreateClient("myhttpclient");

       // This request will be sent with a Authorization-header containing a bearer token
       var result = await client.GetAsync("https://example.com/");

       // Or we can use the typed client we made instead. Any
       // requests made to the HttpClient instance injected will have a bearer token.
       _myMaskinportenHttpClient.DoStuff();
    }
}

// ---- MyExtendedMaskinportenSettings.cs ---- 
public class MyExtendedMaskinportenSettings : MaskinportenSettings 
{ // Extends MaskinportenSettings to avoid having to specify every field in IMaskinportenSettings
    
    public string MyCustomSetting { get; set; }
}

// ---- MyCustomClientDefinition.cs ---- 
public class MyCustomClientDefinition : IClientDefinition
{
    public IMaskinportenSettings ClientSettings { get; set; }

    // The custom client definitions are registered in the DIC as singletons
    public MyCustomClientDefinition(ILogger<MyCustomClientDefinition> logger)
    {
        _logger = logger;
    }

    public async Task<ClientSecrets> GetClientSecrets()
    {
        var myExtendedSettings = (MyExtendedMaskinportenSettings)ClientSettings;
        // use myExtendedSettings.MyCustomSetting
        ...
    }
}

// ---- Program.cs / Startup.cs ---- 
var myExtendedMaskinportenSettings = new MyExtendedMaskinportenSettings();
// We assume `Configuration` is a IConfiguration instance containing the settings from eg. appsettings.json
// and that `services` is a IServiceCollection
Configuration.GetSection("ExtendedMaskinportenSettings").Bind(myExtendedMaskinportenSettings);

// Named client using a custom client definition and settings
services.AddMaskinportenHttpClient<MyCustomClientDefinition>("myhttpclient", myExtendedMaskinportenSettings);

services.AddMaskinportenHttpClient<SettingsJwkClientDefinition, MyMaskinportenHttpClient>(
  Configuration.GetSection("MaskinportenSettings"), clientDefinition =>
{
    clientDefinition.ClientSettings.ExhangeToAltinnToken = true;
    clientDefinition.ClientSettings.UseAltinnTestOrg = true;
    clientDefinition.ClientSettings.TokenExchangeEnvironment = "at24";
});

services.AddSingleton<ITokenCacheProvider, FileTokenCacheProvider>();

// Maskinporten requires a cache implementation. Note: for 1.x of this library, use MemoryCache directly
services.AddSingleton<ITokenCacheProvider, MemoryTokenCacheProvider>();

// We also need at least one HTTP client in order to fetch tokens
services.AddHttpClient();

// Adds service can be used directly, see below. This exposes several GetToken() overloads.
services.AddSingleton<IMaskinportenService, MaskinportenService>();

private async Task<string> GetMaskinportenAccessToken()
{
    try
    {
        string accessToken = null;
        string base64encodedJWK = await _secrets.GetSecretAsync("myBase64EncodedJwkWithPrivateKey");
        TokenResponse accesstokenResponse = await _maskinporten.GetToken(
            base64encodedJWK, _maskinportenSettings.ClientId, _maskinportenSettings.Scope, null);

        return accesstokenResponse.AccessToken;
    }
}