using System;
using System.IO;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using App.Workflow.Test;
using System.Activities;
using Microsoft.Activities.UnitTesting;
using Microsoft.Activities.UnitTesting.Persistence;
using System.Activities.Statements;

namespace App.Tests.Workflow {

    public class MockTimerExtension : DurableTimerExtension {
        protected override void OnCancelTimer(Bookmark bookmark) {
            base.OnCancelTimer(bookmark);
        }

        protected override void OnRegisterTimer(TimeSpan timeout, Bookmark bookmark) {

            // Here's where you can modify the timespan.  Instead of a more formal mock
            // object I have here you could use a Mocking framework to "advance" time
            // by calculating the difference between DateTime.Now() and when the workflow
            // expects to continue from delay.

            // For illustration, I'm intercepting the request to schedule a timer and replacing the
            // timespan with a 15 second timer.
            base.OnRegisterTimer(new TimeSpan(0, 0, 15), bookmark);
        }
    }

    [TestClass]
    public class WorkflowTests {


        // Func<TimerExtension> that returns an instance of our MockTimerExtension
        public TimerExtension GetTimerExtension() {
            return new MockTimerExtension();
        }

        [TestMethod]
        public void InitWorkflow() {

            // A humble Workflow with a 15 minute delay -- and some Writelines around it
            var _wf = new WF_1();

            // The UnitTesting Host from Microsoft.Activities.UnitTesting
            var _host = WorkflowApplicationTest.Create<WF_1>(_wf);

            try {

                // Instrumenting the WF Test Application to call a method when a demand for the "TimerExtension" is made.
                // This works on all the flavors of hosts -- ServiceHost, WFApplication and the UnitTesting versions of these as well.
                _host.TestWorkflowApplication.Extensions.Add<TimerExtension>(GetTimerExtension);

                // Put the Workflow under Test
                _host.TestActivity();

                _host.WaitForIdleEvent();

                // Resume
                _host.TestWorkflowApplication.Run();

                // Wait for completion
                _host.WaitForUnloadedEvent();

            } finally {
                // Write Output of WF tracing participant
                _host.Tracking.Trace();
            }

        }
    }
}