Program.cs

using System.Reflection;
using Asp.Versioning;
using Asp.Versioning.ApiExplorer;
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);
// Customize Logger
// builder.Logging.ClearProviders();
// builder.Logging.AddConsole();
builder.Host.UseSerilog();

// Add services to the container.
builder.Services.AddControllers(options =>
{
    options.ReturnHttpNotAcceptable = true;
})
.AddNewtonsoftJson()
.AddXmlDataContractSerializerFormatters();

// add additional details when returning error status code
builder.Services.AddProblemDetails(options => 
{
    options.CustomizeProblemDetails = context => 
    {
        context.ProblemDetails.Extensions.Add("additionalInfo", "Additional Info Example");
        context.ProblemDetails.Extensions.Add("server", Environment.MachineName); // add server name to the error detail
    };
});


builder.Services.AddEndpointsApiExplorer();

builder.Services.AddSingleton<FileExtensionContentTypeProvider>();

// Register custom service to container
#if DEBUG
builder.Services.AddTransient<IMailService, LocalMailService>();
#else
builder.Services.AddTransient<IMailService, CloudMailService>();
#endif

builder.Services.AddSingleton<CitiesDataStore>();

// Register DbContext
builder.Services.AddDbContext<CityInfoContext>(dbContextOptions =>
{
    dbContextOptions.UseSqlite(builder.Configuration["ConnectionStrings:CityInfoDBConnectionString"]);
});

// add repository
builder.Services.AddScoped<ICityInfoRepository, CityInfoRepository>();

// add automapper
builder.Services.AddAutoMapper(AppDomain.CurrentDomain.GetAssemblies());

// add token authentication
builder.Services.AddAuthentication("Bearer").AddJwtBearer(options => 
{
    options.TokenValidationParameters = new ()
    {
        ValidateIssuer = true,
        ValidateAudience = true,
        ValidateIssuerSigningKey = true,
        ValidIssuer = builder.Configuration["Authentication:Issuer"],
        ValidAudience = builder.Configuration["Authentication:Audience"],
        IssuerSigningKey = new SymmetricSecurityKey(Convert.FromBase64String(builder.Configuration["Authentication:SecretForKey"]))
    };
});

// Add Authorization Policies
builder.Services.AddAuthorization(options => 
{
    options.AddPolicy("MustBeFromParis", policy => 
    {
        policy.RequireAuthenticatedUser();
        policy.RequireClaim("City", "Paris");
    });
});

// add api versioning
builder.Services.AddApiVersioning(setupAction => 
{
    setupAction.ReportApiVersions = true;
    setupAction.AssumeDefaultVersionWhenUnspecified = true;
    setupAction.DefaultApiVersion = new ApiVersion(1, 0);
}).AddMvc()
.AddApiExplorer(setupAction => 
{
    setupAction.SubstituteApiVersionInUrl = true;
});

var apiVersionDescriptionProvider = builder.Services.BuildServiceProvider().GetRequiredService<IApiVersionDescriptionProvider>();

// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddSwaggerGen(setupAction =>
{
    // Add XML description
    foreach (var description in apiVersionDescriptionProvider.ApiVersionDescriptions)
    {
        setupAction.SwaggerDoc($"{description.GroupName}",
        new ()
        {
            Title = "City Info API",
            Version = description.ApiVersion.ToString(),
            Description = "Through this API you can access cities and their points of interest."
        });
    }
    var xmlCommentsFile = $"{Assembly.GetExecutingAssembly().GetName().Name}.xml";
    var xmlCommentsFullPath = Path.Combine(AppContext.BaseDirectory, xmlCommentsFile);

    setupAction.IncludeXmlComments(xmlCommentsFullPath);

    // Add token authentication in Swagger
    setupAction.AddSecurityDefinition("CityInfoBearerAuth", new ()
    {
        Type = SecuritySchemeType.Http,
        Scheme = "Bearer",
        Description = "Input a valid token to access this API"
    });

    // Use token authentication in Swagger
    setupAction.AddSecurityRequirement(new ()
    {
        {
            new ()
            {
                Reference = new OpenApiReference
                {
                    Type = ReferenceType.SecurityScheme,
                    Id = "CityInfoBearerAuth"
                }
            },
            new List<string>()
        }
    });
});

var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler();
}

if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI(setupAction => 
    {
        var descriptions = app.DescribeApiVersions();
        foreach (var description in descriptions)
        {
            setupAction.SwaggerEndpoint($"/swagger/{description.GroupName}/swagger.json", description.GroupName.ToUpperInvariant());
        }
    });
}

app.UseHttpsRedirection();

app.UseRouting();

app.UseAuthentication();

app.UseAuthorization();

app.UseEndpoints(endpoints => 
{
    endpoints.MapControllers();
});

app.Run();

// Always show Hello World no matter the endpoint
// app.Run(async (context) => 
// {
//     await context.Response.WriteAsync("Hello World");
// });