Top Level API Program

TopLevelWebAPI.cs

using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore;
using Microsoft.AspNetCore.Builder;
using Microsoft.Extensions.DependencyInjection;

// with endpoint routing and JSON endpoints
// see https://github.com/dotnet/aspnetcore/pull/23496/ for more on the JSON helpers
WebHost.CreateDefaultBuilder().
ConfigureServices(s => s.AddSingleton<ContactService>()).
Configure(app => 
{
    app.UseRouting();
    app.UseEndpoints(e => 
    {
        var contactService = e.ServiceProvider.GetRequiredService<ContactService>();

        e.MapGet("/contacts", 
            async c => await c.Response.WriteAsJsonAsync(await contactService.GetAll()));
        e.MapGet("/contacts/{id:int}", 
            async c => await c.Response.WriteAsJsonAsync(await contactService.Get(int.Parse((string)c.Request.RouteValues["id"]))));
        e.MapPost("/contacts", 
            async c => 
            {
                await contactService.Add(await c.Request.ReadFromJsonAsync<Contact>());
                c.Response.StatusCode = 201;
            });
        e.MapDelete("/contacts/{id:int}", 
            async c => 
            {
                await contactService.Delete(int.Parse((string)c.Request.RouteValues["id"]));
                c.Response.StatusCode = 204;
            });
    });
}).Build().Run();