using System.IO;
using System.Text;
using System.Windows;
using System.Windows.Threading;
using AxiOmron.PcbCheck.Options;
using AxiOmron.PcbCheck.Services.Implementations;
using AxiOmron.PcbCheck.Services.Interfaces;
using AxiOmron.PcbCheck.Utils;
using AxiOmron.PcbCheck.ViewModels;
using AxiOmron.PcbCheck.Views.Pages;
using AxiOmron.PcbCheck.Views.Windows;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using NLog.Extensions.Logging;

namespace AxiOmron.PcbCheck;

/// <summary>
/// 表示 WPF 应用入口，负责 Host/DI、配置和日志初始化。
/// </summary>
public partial class App : Application
{
    private static readonly NLog.Logger FallbackLogger = NLog.LogManager.GetCurrentClassLogger();
    private IHost? _host;

    /// <summary>
    /// 获取当前应用服务容器。
    /// </summary>
    public static IServiceProvider Services { get; private set; } = null!;

    /// <summary>
    /// 应用启动入口。
    /// </summary>
    /// <param name="e">启动事件参数。</param>
    protected override async void OnStartup(StartupEventArgs e)
    {
        base.OnStartup(e);
        RegisterGlobalExceptionHandlers();
        try
        {
            Console.OutputEncoding = Encoding.UTF8;
        }
        catch (IOException)
        {
            // WinExe 在没有控制台句柄时忽略
        }

        try
        {
            _host = BuildHost();
            await _host.StartAsync().ConfigureAwait(true);
            Services = _host.Services;
            var mainWindow = Services.GetRequiredService<MainWindow>();
            MainWindow = mainWindow;
            mainWindow.Show();
        }
        catch (Exception ex)
        {
            LogGlobalException("应用启动失败", ex);
            MessageBox.Show($"应用启动失败: {ex.Message}", "Axi Omron PCB Check", MessageBoxButton.OK, MessageBoxImage.Error);
            Shutdown(-1);
        }
    }

    /// <summary>
    /// 应用退出入口。
    /// </summary>
    /// <param name="e">退出事件参数。</param>
    protected override async void OnExit(ExitEventArgs e)
    {
        UnregisterGlobalExceptionHandlers();
        if (_host is not null)
        {
            try
            {
                await ShutdownHelper.StopHostAsync(_host, TimeSpan.FromSeconds(2));
            }
            finally
            {
                _host.Dispose();
            }
        }

        base.OnExit(e);
    }

    /// <summary>
    /// 构建应用 Host 与依赖注入容器。
    /// </summary>
    /// <returns>已构建的 Host 实例。</returns>
    private static IHost BuildHost()
    {
        return Host.CreateDefaultBuilder()
            .ConfigureAppConfiguration((context, configurationBuilder) =>
            {
                configurationBuilder.SetBasePath(AppContext.BaseDirectory);
                configurationBuilder.AddJsonFile("appConfig.json", optional: true, reloadOnChange: false);
                configurationBuilder.AddJsonFile($"appConfig.{context.HostingEnvironment.EnvironmentName}.json", optional: true, reloadOnChange: false);
            })
            .ConfigureLogging(logging =>
            {
                logging.ClearProviders();
                logging.SetMinimumLevel(LogLevel.Information);
                logging.AddNLog();
            })
            .ConfigureServices((context, services) =>
            {
                var appConfig = new AppConfig();
                context.Configuration.Bind(appConfig);

                services.AddSingleton<IConfiguration>(context.Configuration);
                services.AddSingleton<IAppConfigService, AppConfigService>();
                services.AddSingleton(appConfig);
                services.AddSingleton<IAppStateStore, AppStateStore>();
                services.AddSingleton(typeof(IAppLogger<>), typeof(AppLogger<>));
                services.AddSingleton<IDispatcherService, DispatcherService>();
                services.AddSingleton(TimeProvider.System);
                services.AddHttpClient(nameof(AndonService));

                services.AddSingleton<IPlcService, OmronFinsPlcService>();
                services.AddSingleton<IScannerService, TcpDualScannerService>();
                services.AddSingleton<IFileCheckProvider, SftpLookupService>();
                services.AddSingleton<IFileCheckProvider, LocalFileCheckProvider>();
                services.AddSingleton<IFileCheckService, FileCheckService>();
                services.AddSingleton<IAndonService, AndonService>();
                services.AddSingleton<IBoardRecordRepository, CsvBoardRecordRepository>();
                services.AddSingleton<WorkflowHostedService>();
                services.AddSingleton<IWorkflowControlService>(sp => sp.GetRequiredService<WorkflowHostedService>());
                services.AddHostedService(sp => sp.GetRequiredService<WorkflowHostedService>());
                services.AddSingleton<IAdminUnlockDialogService, AdminUnlockDialogService>();

                services.AddSingleton<MainWindowViewModel>();
                services.AddSingleton<SystemSettingViewModel>();
                services.AddSingleton<DashboardPage>();
                services.AddSingleton<SystemSettingsPage>();
                services.AddTransient<AdminUnlockDialog>();
                services.AddSingleton<MainWindow>();
            })
            .Build();
    }

    /// <summary>
    /// 注册全局异常处理器，用于兜底记录 UI 线程、未观察任务和域级异常。
    /// </summary>
    private void RegisterGlobalExceptionHandlers()
    {
        DispatcherUnhandledException += OnDispatcherUnhandledException;
        AppDomain.CurrentDomain.UnhandledException += OnCurrentDomainUnhandledException;
        TaskScheduler.UnobservedTaskException += OnTaskSchedulerUnobservedTaskException;
    }

    /// <summary>
    /// 注销全局异常处理器。
    /// </summary>
    private void UnregisterGlobalExceptionHandlers()
    {
        DispatcherUnhandledException -= OnDispatcherUnhandledException;
        AppDomain.CurrentDomain.UnhandledException -= OnCurrentDomainUnhandledException;
        TaskScheduler.UnobservedTaskException -= OnTaskSchedulerUnobservedTaskException;
    }

    /// <summary>
    /// 处理 UI 线程未捕获异常，记录日志并阻止应用直接闪退。
    /// </summary>
    /// <param name="sender">事件源。</param>
    /// <param name="e">异常事件参数。</param>
    private void OnDispatcherUnhandledException(object sender, DispatcherUnhandledExceptionEventArgs e)
    {
        LogGlobalException("UI 线程未处理异常", e.Exception);
        MessageBox.Show($"程序捕获到未处理异常，已写入日志：{e.Exception.Message}", "Axi Omron PCB Check", MessageBoxButton.OK, MessageBoxImage.Warning);
        e.Handled = true;
    }

    /// <summary>
    /// 处理未观察任务异常，记录日志并标记为已观察。
    /// </summary>
    /// <param name="sender">事件源。</param>
    /// <param name="e">异常事件参数。</param>
    private void OnTaskSchedulerUnobservedTaskException(object? sender, UnobservedTaskExceptionEventArgs e)
    {
        LogGlobalException("未观察任务异常", e.Exception);
        e.SetObserved();
    }

    /// <summary>
    /// 处理应用程序域未捕获异常，尽量在进程退出前补充日志。
    /// </summary>
    /// <param name="sender">事件源。</param>
    /// <param name="e">异常事件参数。</param>
    private void OnCurrentDomainUnhandledException(object? sender, UnhandledExceptionEventArgs e)
    {
        var exception = e.ExceptionObject as Exception ?? new Exception(e.ExceptionObject?.ToString() ?? "未知未处理异常");
        LogGlobalException($"应用程序域未处理异常（IsTerminating={e.IsTerminating}）", exception);
    }

    /// <summary>
    /// 统一记录全局异常日志，优先复用宿主日志器，失败时退回 NLog 直接写入。
    /// </summary>
    /// <param name="message">日志消息。</param>
    /// <param name="exception">异常对象。</param>
    private static void LogGlobalException(string message, Exception exception)
    {
        try
        {
            if (Services is not null)
            {
                var logger = Services.GetService<ILogger<App>>();
                logger?.LogError(exception, message);
            }
        }
        catch
        {
            // 忽略宿主日志失败，继续使用回退日志。
        }

        try
        {
            FallbackLogger.Error(exception, message);
        }
        catch
        {
            // 全局兜底日志不再向外抛出。
        }
    }
}