Program.cs

using aspnet.Services;
using aspnet.Data;
using aspnet.Models;
using Microsoft.EntityFrameworkCore;
using Microsoft.IdentityModel.Tokens;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using System.Text;
using aspnet.Middleware;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
// Learn more about configuring OpenAPI at https://aka.ms/aspnet/openapi
builder.Services.AddControllers();
builder.Services.AddOpenApi();
builder.Services.AddDbContext<AppDbContext>(options =>
options.UseSqlite("Data Source=todos.db")
);

builder.Services.AddScoped<TodoService>();

builder.Services.AddScoped<AuthService>();

// Bind the "Gemini" config section to GeminiOptions so services can inject IOptions<GeminiOptions>.
builder.Services.Configure<GeminiOptions>(
    builder.Configuration.GetSection("Gemini")
    );
// Typed HttpClient: the factory injects a properly-managed HttpClient into AiService's ctor.
builder.Services.AddHttpClient<AiService>();

builder.Services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
.AddJwtBearer(options =>
{
    options.TokenValidationParameters = new TokenValidationParameters
    {
        ValidateIssuer = true,
        ValidateAudience = true,
        ValidateLifetime = true,
        ValidateIssuerSigningKey = true,
        ValidIssuer = builder.Configuration["Jwt:Issuer"],
        ValidAudience = builder.Configuration["Jwt:Audience"],
        IssuerSigningKey = new SymmetricSecurityKey(
            Encoding.UTF8.GetBytes(builder.Configuration["Jwt:Key"]!)
        )
    };
});

var app = builder.Build();

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

app.UseHttpsRedirection();
app.MapControllers();

app.UseMiddleware<ExceptionMiddleware>();
app.UseAuthentication();
app.UseAuthorization();

app.Run();