using ChatbotApi.Data.Models;
using DotNetEnv;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.RateLimiting;
using Microsoft.IdentityModel.Tokens;
using System.Text;
using System.Threading.RateLimiting;
using Microsoft.AspNetCore.Identity;
using Microsoft.OpenApi.Models;

// Cargar variables de entorno desde el archivo .env
Env.Load();

var builder = WebApplication.CreateBuilder(args);

// Definimos una política de CORS para permitir solicitudes desde nuestro frontend de Vite
var myAllowSpecificOrigins = "_myAllowSpecificOrigins";
builder.Services.AddCors(options =>
{
    options.AddPolicy(name: myAllowSpecificOrigins,
                      policy =>
                      {
                          policy.WithOrigins("http://192.168.5.129:8081", "http://192.168.5.129:8082", "http://localhost:5173", "http://localhost:5174")
                                .AllowAnyHeader()
                                .AllowAnyMethod();
                      });
});


// 1. Añadimos el DbContext para Entity Framework
var connectionString = builder.Configuration.GetConnectionString("DefaultConnection");
builder.Services.AddDbContext<AppContexto>(options =>
    options.UseSqlServer(connectionString));

// 2. Añadimos ASP.NET Core Identity
builder.Services.AddIdentity<IdentityUser, IdentityRole>(options =>
{
    options.Password.RequireDigit = true;
    options.Password.RequiredLength = 8;
    options.Password.RequireNonAlphanumeric = false;
    options.Password.RequireUppercase = true;
    options.Password.RequireLowercase = false;
})
.AddEntityFrameworkStores<AppContexto>()
.AddDefaultTokenProviders();

builder.Services.AddMemoryCache();

// =========== INICIO DE CONFIGURACIÓN JWT ===========
builder.Services.AddAuthentication(options =>
{
    options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
    options.DefaultChallengeScheme = 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"] ?? throw new InvalidOperationException("La clave JWT no está configurada.")
        ))
    };
});

// RATE LIMITING
builder.Services.AddRateLimiter(options =>
{
    options.AddFixedWindowLimiter(policyName: "fixed", limiterOptions =>
    {
        limiterOptions.PermitLimit = 10; // Permitir 10 peticiones...
        limiterOptions.Window = TimeSpan.FromMinutes(1); // ...por cada minuto.
        limiterOptions.QueueLimit = 2; // Poner en cola hasta 2 peticiones si se excede el límite brevemente.
        limiterOptions.QueueProcessingOrder = QueueProcessingOrder.OldestFirst;
    });

    // Esta función se ejecuta cuando una petición es rechazada
    options.RejectionStatusCode = StatusCodes.Status429TooManyRequests;
});

builder.Services.AddControllers();
builder.Services.AddEndpointsApiExplorer();

builder.Services.AddSwaggerGen(options =>
{
    options.SwaggerDoc("v1", new OpenApiInfo { Title = "Chatbot API", Version = "v1" });
    options.AddSecurityDefinition("Bearer", new OpenApiSecurityScheme
    {
        In = ParameterLocation.Header,
        Description = "Por favor, introduce 'Bearer' seguido de un espacio y el token JWT",
        Name = "Authorization",
        Type = SecuritySchemeType.ApiKey,
        Scheme = "Bearer"
    });

    options.AddSecurityRequirement(new OpenApiSecurityRequirement
    {
        {
            new OpenApiSecurityScheme
            {
                Reference = new OpenApiReference
                {
                    Type = ReferenceType.SecurityScheme,
                    Id = "Bearer"
                }
            },
            new string[] {}
        }
    });
});

var app = builder.Build();

if (app.Environment.IsDevelopment())
{
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();
// =========== CONFIGURACIÓN Y USO DEL MIDDLEWARE DE ENCABEZADOS DE SEGURIDAD ===========
app.UseSecurityHeaders(policy =>
{
    policy.AddDefaultSecurityHeaders(); // Añade los encabezados por defecto
    policy.AddContentSecurityPolicy(builder =>
    {
        builder.AddDefaultSrc().Self();

        // Permisos necesarios para Swagger UI
        builder.AddScriptSrc().Self().UnsafeInline();
        builder.AddStyleSrc().Self().UnsafeInline();
    });
});
app.UseCors(myAllowSpecificOrigins);
app.UseRateLimiter();
app.UseAuthentication();
app.UseAuthorization();
app.MapControllers();
app.Run();