Program.cs

using System.Reflection;
using System.Text;
using CityInfo.Api;
using CityInfo.Api.DbContexts;
using CityInfo.Api.Services;
using Microsoft.AspNetCore.StaticFiles;
using Microsoft.EntityFrameworkCore;
using Microsoft.IdentityModel.Tokens;
using Microsoft.OpenApi.Models;
using Serilog;

Log.Logger = new LoggerConfiguration()
    .MinimumLevel.Debug()
    .WriteTo.Console()
    .WriteTo.File("logs/cityinfo.txt", rollingInterval: RollingInterval.Day)
    .CreateLogger();

var builder = WebApplication.CreateBuilder(args);
// builder.Logging.ClearProviders();  // There is nothing to log - overrides appSettings configuration
// builder.Logging.AddConsole();

builder.Host.UseSerilog();

// Add services to the container.
builder.Services.AddControllers(options =>
    {
        // Define default input or output format
        // options.InputFormatters.Add();
        // options.OutputFormatters.Add();

        // To specify whether the response format is accepted or not
        // Example: Request XML response but it is not supported by the API
        options.ReturnHttpNotAcceptable = true;
    })
    .AddNewtonsoftJson()
    .AddXmlDataContractSerializerFormatters(); // This line adds XML support to the API

// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen(setupAction =>
{
    var xmlCommentsFile = $"{Assembly.GetExecutingAssembly().GetName().Name}.xml";
    var xmlCommentsFullPath = Path.Combine(AppContext.BaseDirectory, xmlCommentsFile);
    
    setupAction.IncludeXmlComments(xmlCommentsFullPath);
    
    setupAction.AddSecurityDefinition("CityInfoApiBearerAuth", new OpenApiSecurityScheme()
    {
        Type = SecuritySchemeType.Http,
        Scheme = "Bearer",
        Description = "Input a valid token to access this API"
    });
    
    setupAction.AddSecurityRequirement(new OpenApiSecurityRequirement
    {
        {
            new OpenApiSecurityScheme
            {
                Reference = new OpenApiReference
                {
                    Type = ReferenceType.SecurityScheme,
                    Id = "CityInfoApiBearerAuth"
                }
            },
            new List<string>()
        }
    });
});

// Adds singleton instance of FileExtensionContentTypeProvider to .NET Core service container.
// This class provides information about the content type (MIME) for a given file extension. 
// It is used to set the content type of an HTTP response based on the file extension of a file being served or downloaded.
builder.Services.AddSingleton<FileExtensionContentTypeProvider>();
#if DEBUG // Compiler directive
builder.Services
    .AddTransient<IMailService,
        LocalMailService>(); // Transient lifetime services are created each time they are requested - lightweight, stateless services
#else
builder.Services.AddTransient<IMailService, CloudMailService>();
#endif
// builder.Services.AddScoped<>();     // Scoped lifetime services are created once per request
// builder.Services.AddSingleton<>();  // Singleton lifetime services are created the first time they are requested

builder.Services.AddSingleton<CitiesDataStore>();
builder.Services.AddDbContext<CityInfoContext>(
    optionsBuilder => optionsBuilder.UseSqlServer(
        builder.Configuration["ConnectionStrings:CityInfoDb"]));
builder.Services.AddScoped<ICityInfoRepository, CityInfoRepository>(); // Repositories are best fit with scoped
builder.Services.AddAutoMapper(AppDomain.CurrentDomain.GetAssemblies());
builder.Services.AddAuthentication("Bearer")
    .AddJwtBearer(options =>
    {
        // How token will be validated
        options.TokenValidationParameters = new TokenValidationParameters
        {
            ValidateIssuer = true,
            ValidateAudience = true,
            ValidateIssuerSigningKey = true,
            ValidIssuer = builder.Configuration["Authentication:Issuer"],
            ValidAudience = builder.Configuration["Authentication:Audience"],
            IssuerSigningKey =
                new SymmetricSecurityKey(Encoding.ASCII.GetBytes(builder.Configuration["Authentication:Secret"]))
        };
    });

builder.Services.AddAuthorization(options =>
{
    options.AddPolicy("MustBeFromAntwerp", policyBuilder =>
    {
        policyBuilder.RequireAuthenticatedUser();
        policyBuilder.RequireClaim("city", "Antwerp");
    });
});

builder.Services.AddApiVersioning(setupAction =>
{
    setupAction.AssumeDefaultVersionWhenUnspecified = true;
    setupAction.DefaultApiVersion = new Microsoft.AspNetCore.Mvc.ApiVersion(1, 0);
    setupAction.ReportApiVersions = true;
});

var app = builder.Build();

// Configure the HTTP request pipeline
// Middleware
if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();
app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
    app.MapControllers(); // Routing
});
app.Run();