using MP.RIOC.Services;
using MP.RIOC.Services;
using NLog;
using NLog.Web;
using StackExchange.Redis;
using System.Diagnostics;
using System.Net;
using System.Reflection;

var builder = WebApplication.CreateBuilder(args);

// recupero env corrente
var env = builder.Environment;
var logger = LogManager.Setup()
                .LoadConfigurationFromAppSettings()
                .GetCurrentClassLogger();

var assemblyVersion = Assembly.GetExecutingAssembly().GetName().Version?.ToString();
logger.Info($"MP.RIOC | Program.cs: startup | v.{assemblyVersion}");
logger.Info($"Current ASPNETCORE_ENVIRONMENT: {env.EnvironmentName}");

// Config setup
ConfigurationManager configuration = builder.Configuration;
// REDIS setup
logger.Info("Config OK");
string confRedis = configuration.GetConnectionString("Redis");
string redisSrvAddr = confRedis.Substring(0, confRedis.IndexOf(":"));
logger.Info("Setup REDIS OK");

// 1. Configurazione dell'invoker personalizzato (Risolve i tuoi errori)
var httpClientInvoker = new HttpMessageInvoker(new SocketsHttpHandler
{
    UseProxy = false,
    AllowAutoRedirect = false,
    AutomaticDecompression = DecompressionMethods.None,
    UseCookies = false,
    // Correzione per il tracing: usa il propagatore corrente di sistema
    ActivityHeadersPropagator = DistributedContextPropagator.Current,
    ConnectTimeout = TimeSpan.FromSeconds(15),

    // Gestione certificato (ignora errori per localhost/test)
    SslOptions = new System.Net.Security.SslClientAuthenticationOptions
    {
        RemoteCertificateValidationCallback = (sender, cert, chain, sslPolicyErrors) => true
    }
});

builder.Services.AddSingleton(httpClientInvoker);
builder.Services.AddHttpForwarder();

// avvio oggetto shared x redis...
var redisMux = ConnectionMultiplexer.Connect(confRedis);
builder.Services.AddSingleton<IConnectionMultiplexer>(redisMux);

// Registrazione dei servizi custom
builder.Services.AddSingleton<PreserveBodyTransformer>();
builder.Services.AddSingleton<RouteStatsManager>();
builder.Services.AddHostedService<MetricsCalcService>();
builder.Services.AddHostedService<MetricsDbFlushService>();
builder.Services.AddSingleton<LuaScriptProvider>();

logger.Info("Standard service configured");

// WeightProvider: Redis/Memory da config
var weightOnRedis = builder.Configuration.GetValue<bool>("ServerConf:RedisWeight", false);
if (weightOnRedis)
{
    builder.Services.AddSingleton<IWeightProvider, RedisWeightProvider>();
}
else
{
    builder.Services.AddSingleton<IWeightProvider, InMemoryWeightProvider>();
}
logger.Info($"Weight service configured | use Redis: {weightOnRedis}");

// RouteManager registration (singleton)
builder.Services.AddSingleton<RouteManager>();
logger.Info("Singleton Route Manager registered");

// aggiunta pagina razor di stato
builder.Services.AddRazorPages();

var app = builder.Build();

// 1. Configurazione Base Path
string baseUrl = configuration.GetValue<string>("ServerConf:BaseUrlIoc") ?? "/MP/RIOC";
app.UsePathBase(baseUrl);

// 2. Middleware statici (essenziali per CSS/JS delle pagine Razor)
app.UseStaticFiles();

// 3. Abilita il Routing (necessario per MapGet e MapRazorPages)
app.UseRouting();

// 4. Logging middleware
app.Use(async (ctx, next) =>
{
    logger.Debug($"Incoming request PathBase='{ctx.Request.PathBase}' Path='{ctx.Request.Path}'");
    await next();
});

// 5. Il cuore del Proxy (MapWhen è terminale per le richieste che lo soddisfano)
string routePath = configuration.GetValue<string>("ServerConf:RoutePath") ?? "/api/IOB";
string fullPath = $"{baseUrl}{routePath}".Replace("//", "/");
logger.Info($"BaseUrl: {baseUrl}");
app.MapWhen(ctx => ctx.Request.Path.StartsWithSegments(routePath, StringComparison.OrdinalIgnoreCase),
    builder =>
    {
        builder.Run(async ctx =>
        {
            var routeManager = ctx.RequestServices.GetRequiredService<RouteManager>();
            await routeManager.HandleAsync(ctx);
        });
    });

// 6. Definizione degli Endpoints locali
app.MapRazorPages();

app.MapGet("/router-status", (RouteStatsManager stats) => Results.Ok(new
{
    Status = "Online",
    Version = assemblyVersion,
    Mode = weightOnRedis ? "Redis" : "InMemory",
    Time = DateTime.Now,
    Metrics = stats.Snapshot()
}));

// 7. Fallback "intelligente"
// Invece di app.Run, usiamo MapFallback che viene eseguito SOLO se nessun altro endpoint o MapWhen ha risposto
app.MapFallback(async context =>
{
    context.Response.StatusCode = 404;
    await context.Response.WriteAsync("Router: Endpoint non trovato o non mappato.");
});

app.Run();