//-----------------------------------------------------------------------
// <copyright file="CoordinatorBase.cs" company="Outercurve Foundation">
//     Copyright (c) Outercurve Foundation. All rights reserved.
// </copyright>
//-----------------------------------------------------------------------

namespace DotNetOpenAuth.Test {
	using System;
	using System.Diagnostics.Contracts;
	using System.Threading;
	using DotNetOpenAuth.Messaging;
	using DotNetOpenAuth.OpenId.RelyingParty;
	using DotNetOpenAuth.Test.Mocks;
	using NUnit.Framework;

	internal abstract class CoordinatorBase<T1, T2> {
		private Action<T1> party1Action;
		private Action<T2> party2Action;

		protected CoordinatorBase(Action<T1> party1Action, Action<T2> party2Action) {
			Requires.NotNull(party1Action, "party1Action");
			Requires.NotNull(party2Action, "party2Action");

			this.party1Action = party1Action;
			this.party2Action = party2Action;
		}

		protected internal Action<IProtocolMessage> IncomingMessageFilter { get; set; }

		protected internal Action<IProtocolMessage> OutgoingMessageFilter { get; set; }

		internal abstract void Run();

		protected void RunCore(T1 party1Object, T2 party2Object) {
			Thread party1Thread = null, party2Thread = null;
			Exception failingException = null;

			// Each thread we create needs a surrounding exception catcher so that we can
			// terminate the other thread and inform the test host that the test failed.
			Action<Action> safeWrapper = (action) => {
				try {
					TestBase.SetMockHttpContext();
					action();
				} catch (Exception ex) {
					// We may be the second thread in an ThreadAbortException, so check the "flag"
					lock (this) {
						if (failingException == null || (failingException is ThreadAbortException && !(ex is ThreadAbortException))) {
							failingException = ex;
							if (Thread.CurrentThread == party1Thread) {
								party2Thread.Abort();
							} else {
								party1Thread.Abort();
							}
						}
					}
				}
			};

			// Run the threads, and wait for them to complete.
			// If this main thread is aborted (test run aborted), go ahead and abort the other two threads.
			party1Thread = new Thread(() => { safeWrapper(() => { this.party1Action(party1Object); }); });
			party2Thread = new Thread(() => { safeWrapper(() => { this.party2Action(party2Object); }); });
			party1Thread.Name = "P1";
			party2Thread.Name = "P2";
			try {
				party1Thread.Start();
				party2Thread.Start();
				party1Thread.Join();
				party2Thread.Join();
			} catch (ThreadAbortException) {
				party1Thread.Abort();
				party2Thread.Abort();
				throw;
			} catch (ThreadStartException ex) {
				if (ex.InnerException is ThreadAbortException) {
					// if party1Thread threw an exception 
					// (which may even have been intentional for the test)
					// before party2Thread even started, then this exception
					// can be thrown, and should be ignored.
				} else {
					throw;
				}
			}

			// Use the failing reason of a failing sub-thread as our reason, if anything failed.
			if (failingException != null) {
				throw new AssertionException("Coordinator thread threw unhandled exception: " + failingException, failingException);
			}
		}
	}
}