Program.cs

using GoogleBooksApp.Models;
using GoogleBooksApp.Services;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Identity.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore;
using Microsoft.OpenApi.Models;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddControllersWithViews();
builder.Services.AddRazorPages(); // Add this line
builder.Services.AddSingleton<GoogleBooksApiClient>();

builder.Services.AddSwaggerGen(c => { c.SwaggerDoc("v1", new OpenApiInfo { Title = "BooksLibrary", Version = "v1" }); });

builder.Services.Configure<IdentityOptions>(opts =>
{
    opts.Password.RequiredLength = 6;
    opts.Password.RequireNonAlphanumeric = false;
    opts.Password.RequireLowercase = false;
    opts.Password.RequireUppercase = false;
    opts.Password.RequireDigit = false;
    opts.User.RequireUniqueEmail = true;
    opts.User.AllowedUserNameCharacters = "abcdefghijklmnopqrstuvwxyz";
});

builder.Services.AddDbContext<ApplicationDbContext>(options =>
    options.UseSqlite(builder.Configuration.GetConnectionString("DefaultConnection")));

builder.Services.AddDefaultIdentity<User>(options => options.SignIn.RequireConfirmedAccount = true)
    .AddEntityFrameworkStores<ApplicationDbContext>();

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsProduction() || !app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Home/Error");
    app.UseHsts();
}

app.UseHttpsRedirection();
app.UseStaticFiles();

app.UseRouting();

app.UseAuthentication();
app.UseAuthorization();

app.MapControllerRoute(
    name: "default",
    pattern: "{controller=Home}/{action=Index}/{id?}");

app.MapRazorPages();

app.UseSwagger();
app.UseSwaggerUI(options => { options.SwaggerEndpoint("/swagger/v1/swagger.json", "WebApp"); });

app.Run();