using System;
using System.Threading;
using System.Threading.Tasks;

namespace Dela.Mono.Examples
{
	public class HelloWorld
	{
		private static int delayA = 3000;
		private static int delayB = 3000;
		
		private static void Log(string message)
		{
			Console.WriteLine("{0} {1}", DateTime.Now, message);
		}
		
		private static Task<int> LongCalcAsync(int x, int delay)
		{
			return Task.Factory.StartNew<int>(() => {
				return LongCalc(x, delay);
			});
		}
		
		private static int LongCalc(int x, int delay)
		{
			Log(String.Format("calc {0}", x));
			Thread.Sleep(delay);
			Log(String.Format("done {0}", x));
			return x;
		}
		
		private static void Bar()
		{
			Log("bar");
		}
		
		// --------------------------------
		
		
		
		private static async void Foo1()
		{
			var a = await LongCalcAsync(1, delayA);
			var b = await LongCalcAsync(2, delayB);
			Log(String.Format("foo {0} {1}", a, b));
		}
		
		private static async void Foo2()
		{
			var ca = LongCalcAsync(1, delayA);
			var cb = LongCalcAsync(2, delayB);
			var a = await ca;
			var b = await cb;
			Log(String.Format("foo {0} {1}", a, b));
		}
		
		private static async void Foo3a()
		{
			await Foo3b();
		}
		
		private static Task Foo3b()
		{
			return Task.Factory.StartNew(() => {
				var a = LongCalc(1, delayA);
				var b = LongCalc(2, delayB);
				Log(String.Format("foo {0} {1}", a, b));
			});
		}
		
		// --------------------------------
		
		
		
		private static void Test1()
		{
			Foo1();
			Bar();
			Thread.Sleep(10000);
		}
		
		private static void Test2()
		{
			Foo2();
			Bar();
			Thread.Sleep(10000);
		}
		
		private static void Test3a()
		{
			Foo3a();
			Bar();
			Thread.Sleep(10000);
		}
		
		private static async void Test3b()
		{
			var done = Foo3b();
			Bar();
			await done;
		}
		
		// --------------------------------
		
		
		
		public static void Main(string[] args)
		{
			Test1();
			Console.WriteLine("--------");
			Test2();
			Console.WriteLine("--------");
			Test3a();
			Console.WriteLine("--------");
			Test3b();
			Thread.Sleep(10000);
		}
	} 
}