using System;
using System.Threading;
using NUnit.Framework;

using Amib.Threading;

namespace WorkItemsGroupTests
{
	/// <summary>
	/// Summary description for TestWaitForIdle.
	/// </summary>
	[TestFixture]
	[Category("WorkItemsGroup")]
	public class TestWaitForIdle
	{
	    /// <summary>
        /// Example of waiting for idle
        /// </summary>
        [Test]
        public void WaitForIdle() 
        { 
            SmartThreadPool smartThreadPool = new SmartThreadPool(10*1000, 25, 0);
			IWorkItemsGroup workItemsGroup = smartThreadPool.CreateWorkItemsGroup(int.MaxValue);

            ManualResetEvent isRunning = new ManualResetEvent(false);

            for (int i = 0; i < 4; ++i)
            {
                workItemsGroup.QueueWorkItem(delegate { isRunning.WaitOne(); });
            }

            bool success = !workItemsGroup.WaitForIdle(1000);

            isRunning.Set();

            success = success && workItemsGroup.WaitForIdle(1000);

            smartThreadPool.Shutdown();

            Assert.IsTrue(success);
        } 

		[Test]
		public void WaitForIdleOnSTPThread() 
		{ 
			SmartThreadPool smartThreadPool = new SmartThreadPool(10*1000, 25, 0);
			IWorkItemsGroup workItemsGroup = smartThreadPool.CreateWorkItemsGroup(int.MaxValue);

			IWorkItemResult wir = workItemsGroup.QueueWorkItem(
				new WorkItemCallback(this.DoWaitForIdle), 
				workItemsGroup);

			Exception e;
			wir.GetResult(out e);

			smartThreadPool.Shutdown();

			Assert.IsNotNull(e);
		}

		[Test]
		public void WaitForIdleOnSTPThreadForAnotherWorkItemsGroup()
		{ 
			SmartThreadPool smartThreadPool = new SmartThreadPool(10*1000, 25, 0);
			IWorkItemsGroup workItemsGroup1 = smartThreadPool.CreateWorkItemsGroup(int.MaxValue);
			IWorkItemsGroup workItemsGroup2 = smartThreadPool.CreateWorkItemsGroup(int.MaxValue);

			workItemsGroup1.QueueWorkItem(
				new WorkItemCallback(this.DoSomeWork), 
				1000);

			workItemsGroup1.QueueWorkItem(
				new WorkItemCallback(this.DoSomeWork), 
				1000);

			IWorkItemResult wir = workItemsGroup2.QueueWorkItem(
				new WorkItemCallback(this.DoWaitForIdle), 
				workItemsGroup1);

			Exception e;
			wir.GetResult(out e);

			smartThreadPool.Shutdown();

			Assert.IsNull(e);
		} 


        private int _x = 0;
        private object DoSomeWork(object state)
        {
            int sleepTime = (int)state;
            int newX = Interlocked.Increment(ref _x);
            Console.WriteLine("{0}: Enter, newX = {1}", DateTime.Now.ToLongTimeString(), newX);
            Console.WriteLine("{0}: Sleeping for {1} ms", DateTime.Now.ToLongTimeString(), sleepTime);
            Thread.Sleep(sleepTime);
            newX = Interlocked.Increment(ref _x);
            Console.WriteLine("{0}: Leave, newX = {1}", DateTime.Now.ToLongTimeString(), newX);
            return 1;
        }

		private object DoWaitForIdle(object state)
		{ 
			IWorkItemsGroup workItemsGroup = state as IWorkItemsGroup;
			workItemsGroup.WaitForIdle();
			return null;
		}


        [Test]
        public void WaitForIdleWithCancel()
        {
            SmartThreadPool smartThreadPool = new SmartThreadPool(10 * 1000, 1, 1);
            IWorkItemsGroup workItemsGroup = smartThreadPool.CreateWorkItemsGroup(2);

            _x = 0;

            IWorkItemResult wir1 = workItemsGroup.QueueWorkItem(new WorkItemCallback(this.DoSomeWork), 1000);
            IWorkItemResult wir2 = workItemsGroup.QueueWorkItem(new WorkItemCallback(this.DoSomeWork), 1000);
            IWorkItemResult wir3 = workItemsGroup.QueueWorkItem(new WorkItemCallback(this.DoSomeWork), 1000);

            while (0 == _x)
            {
                Thread.Sleep(10);
            }

            Console.WriteLine("{0}: Cancelling WIG", DateTime.Now.ToLongTimeString());
            workItemsGroup.Cancel();

            // At this point:
            // The first work item is running
            // The second work item is cancelled, but waits in the STP queue
            // The third work item is cancelled.

            Assert.AreEqual(1, _x);

            Assert.IsTrue(wir2.IsCanceled);

            Assert.IsTrue(wir3.IsCanceled);

            // Make sure the workItemsGroup is still idle
            Assert.IsFalse(workItemsGroup.IsIdle);

            Console.WriteLine("{0}: Waiting for 1st result", DateTime.Now.ToLongTimeString());
            wir1.GetResult();

            Assert.AreEqual(2, _x);

            bool isIdle = workItemsGroup.WaitForIdle(100);

            Assert.IsTrue(isIdle);

            smartThreadPool.Shutdown();
        }
	}
}