using Bitget_Server.Application.BackgroundServices;
using Bitget_Server.Application.Options;
using Bitget_Server.Application.Services;
using Bitget_Server.Application.State;
using Bitget_Server.Infrastructure.Bitget;
using Bitget_Server.Infrastructure.Utils;
using Microsoft.OpenApi.Models;
using Serilog;

var builder = WebApplication.CreateBuilder(args);

// =========================================================================
// 1. Kestrel: HTTP only / port 5000
// =========================================================================
builder.WebHost.ConfigureKestrel(options =>
{
    options.ListenAnyIP(5000); // HTTP 전용, HTTPS 사용하지 않음
});

// =========================================================================
// 2. Options 바인딩
// =========================================================================
builder.Services.Configure<BitgetOptions>(builder.Configuration.GetSection(BitgetOptions.SectionName));
var bitgetOptions = builder.Configuration.GetSection(BitgetOptions.SectionName).Get<BitgetOptions>() ?? new BitgetOptions();

// =========================================================================
// 3. 영속화 경로 설정 (BaseSettings<GlobalOptions>.StorageDirectory)
//    컨테이너에서는 /data, 로컬에서는 ./data 로 마운트됨
// =========================================================================
var dataDir = Path.GetFullPath(bitgetOptions.DataDirectory);
var logDir = Path.GetFullPath(bitgetOptions.LogDirectory);
Directory.CreateDirectory(dataDir);
Directory.CreateDirectory(logDir);
BaseSettings<GlobalOptions>.StorageDirectory = dataDir;

// =========================================================================
// 4. Serilog 구성 (Console + 일자별 File Sink)
// =========================================================================
Log.Logger = new LoggerConfiguration()
    .MinimumLevel.Is(bitgetOptions.LogDebugWrite
        ? Serilog.Events.LogEventLevel.Debug
        : Serilog.Events.LogEventLevel.Information)
    .MinimumLevel.Override("Microsoft.AspNetCore", Serilog.Events.LogEventLevel.Warning)
    .Enrich.FromLogContext()
    .WriteTo.Console()
    .WriteTo.Map(
        keyPropertyName: "SourceContext",
        defaultKey: "general",
        configure: (key, wt) => wt.File(
            path: Path.Combine(logDir, "bitget-.log"),
            rollingInterval: RollingInterval.Day,
            retainedFileCountLimit: 30,
            outputTemplate: "[{Timestamp:HH:mm:ss.fff} {Level:u3}] {SourceContext} {Message:lj}{NewLine}{Exception}"))
    .CreateLogger();

builder.Host.UseSerilog();

// =========================================================================
// 5. DI 등록 - 상태 / 설정 싱글톤
// =========================================================================
builder.Services.AddSingleton<MarketState>();
builder.Services.AddSingleton(sp => GlobalOptions.Instance); // BaseSettings 기반 파일 영속화 싱글톤
builder.Services.AddSingleton<PriceLevelTracker>();

// 기본 API 키 자동 선택 (GlobalOptions.SelectAPI 가 비어 있으면 appsettings.json 의 DefaultApiId 로 초기화)
// 반드시 다른 HostedService 보다 먼저 등록되어야 함 (HostedServices 는 등록 순서대로 StartAsync).
builder.Services.AddHostedService<ApiKeyBootstrapper>();

// =========================================================================
// 6. DI 등록 - Bitget Infrastructure
// =========================================================================
builder.Services.AddSingleton(sp => new BitgetRateLimiter(
    bitgetOptions.RateLimitPerSecond,
    sp.GetRequiredService<ILogger<BitgetRateLimiter>>()));

// Bitget 단일 엔드포인트만 호출하므로 HttpClient 를 Singleton 으로 공유해도 안전.
// (BackgroundService 가 Singleton 이므로 BitgetClient 도 Singleton 이어야 캡처 문제가 없음)
builder.Services.AddSingleton(sp =>
{
    var http = new HttpClient { Timeout = TimeSpan.FromSeconds(30) };
    http.DefaultRequestHeaders.Add("User-Agent", "Bitget_Server/1.0");
    return http;
});
builder.Services.AddSingleton<BitgetClient>();
builder.Services.AddSingleton<BitgetWebSocketClient>();

// =========================================================================
// 7. DI 등록 - Application Services (모두 Singleton: 상태 보관 + BackgroundService 에서 참조)
// =========================================================================
builder.Services.AddSingleton<SettingsService>();
builder.Services.AddSingleton<BitgetTradingService>();
builder.Services.AddSingleton<InitialCandleLoader>();
builder.Services.AddSingleton<SignalProcessService>();

// =========================================================================
// 8. DI 등록 - BackgroundServices (HostedServices)
// =========================================================================
builder.Services.AddHostedService<MarketInfoBackgroundService>();
builder.Services.AddHostedService<WebSocketCalcBackgroundService>();
builder.Services.AddHostedService<SignalProcessBackgroundService>();

// =========================================================================
// 9. MVC / Swagger / ProblemDetails
// =========================================================================
builder.Services.AddControllers()
    .AddNewtonsoftJson(opts =>
    {
        opts.SerializerSettings.ReferenceLoopHandling =
            Newtonsoft.Json.ReferenceLoopHandling.Ignore;
        opts.SerializerSettings.NullValueHandling =
            Newtonsoft.Json.NullValueHandling.Ignore;
    });

builder.Services.AddProblemDetails();
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen(options =>
{
    options.SwaggerDoc("v1", new OpenApiInfo
    {
        Title = "Bitget Server",
        Version = "v1",
        Description = "기존 Bitget WinForms 애플리케이션을 ASP.NET Core 8 REST API 로 이식한 서버."
    });
});

// =========================================================================
// 10. 미들웨어 파이프라인 - HTTPS 리디렉션 없음
// =========================================================================
var app = builder.Build();

app.UseExceptionHandler();
app.UseStatusCodePages();

// 정적 파일 (wwwroot/index.html 등). UseStaticFiles 앞에 UseDefaultFiles 필수.
app.UseDefaultFiles();
app.UseStaticFiles();

// Swagger 는 환경 불문 항상 활성화
app.UseSwagger();
app.UseSwaggerUI(options =>
{
    options.SwaggerEndpoint("/swagger/v1/swagger.json", "Bitget Server v1");
    options.RoutePrefix = "swagger";
});

app.UseSerilogRequestLogging();

app.MapControllers();

// 루트에 wwwroot/index.html 이 없을 경우에만 Swagger 로 폴백 리다이렉트
app.MapFallback(() => Results.Redirect("/swagger"));

Log.Information("Bitget_Server 시작 — URL http://*:5000, DataDir={DataDir}, LogDir={LogDir}", dataDir, logDir);

try
{
    app.Run();
}
finally
{
    Log.CloseAndFlush();
}

/// <summary>
/// 애플리케이션 시작 시 appsettings 의 DefaultApiId 로 GlobalOptions.SelectAPI 를 초기화한다.
/// </summary>
internal sealed class ApiKeyBootstrapper : IHostedService
{
    private readonly IServiceProvider _sp;
    public ApiKeyBootstrapper(IServiceProvider sp) => _sp = sp;

    public Task StartAsync(CancellationToken cancellationToken)
    {
        try
        {
            var global = _sp.GetRequiredService<GlobalOptions>();
            var opts = _sp.GetRequiredService<Microsoft.Extensions.Options.IOptions<BitgetOptions>>().Value;

            if (global.SelectAPI == null && opts.ApiKeys?.Count > 0)
            {
                global.SelectAPI = opts.ApiKeys.FirstOrDefault(k => k.Id == opts.DefaultApiId)
                    ?? opts.ApiKeys.First();
                global.Save();
            }
        }
        catch (Exception ex)
        {
            Log.Warning(ex, "ApiKey 부트스트랩 실패 — 이후 /api/settings/api-key 로 수동 설정 필요");
        }

        return Task.CompletedTask;
    }

    public Task StopAsync(CancellationToken cancellationToken) => Task.CompletedTask;
}