using nanoFramework.Hosting;
using nanoFramework.DependencyInjection;

namespace Hosting
{
    public class Program
    {
        public static void Main()
        {
            IHost host = CreateHostBuilder().Build();
            
            // starts application and blocks the main calling thread 
            host.Run();
        }

        public static IHostBuilder CreateHostBuilder() =>
            Host.CreateDefaultBuilder()
                .ConfigureServices(services =>
                {
                    services.AddSingleton(typeof(BackgroundQueue));
                    services.AddHostedService(typeof(SensorService));
                    services.AddHostedService(typeof(DisplayService));
                });
    }
}

public class CustomService : IHostedService
{
    public void Start() { }

    public void Stop() { }
}

public class SensorService : BackgroundService
{
    protected override void ExecuteAsync()
    {
        while (!CancellationRequested)
        {
            // to allow other threads time to process include 
            // at least one millsecond sleep in loop
            Thread.Sleep(1);
        }
    }
}

public class DisplayService : SchedulerService
{
    // represents a timer control that involks ExecuteAsync at a 
    // specified interval of time repeatedly
    public DisplayService() : base(TimeSpan.FromSeconds(1)) {}

    protected override void ExecuteAsync(object state)
    {   
    }
}

public static IServiceCollection AddLogging(this IServiceCollection services, LogLevel level)
{
    if (services == null)
    {
        throw new ArgumentNullException();
    }

    var loggerFactory = new DebugLoggerFactory();
    LogDispatcher.LoggerFactory = loggerFactory;

    var logger = (DebugLogger)loggerFactory.GetCurrentClassLogger();
    logger.MinLogLevel = level;

    // using TryAdd prevents duplicate logging objects if AddLogging() 
    // is added more then once to ConfigureServices
    services.TryAdd(new ServiceDescriptor(typeof(ILogger), logger));
    services.TryAdd(new ServiceDescriptor(typeof(ILoggerFactory), loggerFactory));

    return services;
}

public static IHostBuilder CreateHostBuilder() =>
    Host.CreateDefaultBuilder()
        .ConfigureServices(services =>
        {
            services.AddLogging(LogLevel.Debug);
            services.AddSingleton(typeof(LoggingService));
        });

public class LoggingService : IHostedService
{
    private ILogger Logger { get; set; }

    public LoggingService(ILogger logger)
    {
        Logger = logger;
    }

    public void Start()
    {
        Logger.Log(LogLevel.Information, new EventId(10, "Start"), "Logging started", null);
    }

    public void Stop()
    {
        Logger.Log(LogLevel.Information, new EventId(11, "Stop"), "Logging stopped", null);
    }
}

public static IHostBuilder CreateHostBuilder() =>
    Host.CreateDefaultBuilder()
        .UseDefaultServiceProvider(options =>
        {
            options.ValidateOnBuild = false;
        });