using System;
using System.Linq;
using JD.Application.Actions;
using JD.Timeline.Document;
using TeaBox;
using TeaBox.ObjectModel.Transactions;
using NUnit.Framework;
using JD.Serialization;
using Action = System.Action;
namespace TRecTests
{
    [TestFixture]
    public class TapeUndoerTests
    {
        [Test]
        public void Test_undoer_can_restore_the_previous_state_of_the_tape()
        {
            var tape = new Tape();
            var undoer = new TapeUndoer(tape, new CommandStack(), new DummyModerator());

            AssertClipsAre(tape);
            tape.CreateAndAddClip(typeof(AlphaClip));
            tape.CreateAndAddClip(typeof(TranslationClip));
            AssertClipsAre(tape, typeof(AlphaClip), typeof(TranslationClip));

            undoer.CommandStack.Undo();
            AssertClipsAre(tape, typeof(AlphaClip));

            undoer.CommandStack.Undo();
            AssertClipsAre(tape);
        }

        [Test]
        public void Test_undoer_can_redo_operations()
        {
            var tape = new Tape();
            var undoer = new TapeUndoer(tape, new CommandStack(), new DummyModerator());

            AssertClipsAre(tape);
            tape.CreateAndAddClip(typeof(AlphaClip));
            tape.CreateAndAddClip(typeof(TranslationClip));
            AssertClipsAre(tape, typeof(AlphaClip), typeof(TranslationClip));

            undoer.CommandStack.Undo();
            undoer.CommandStack.Undo();
            undoer.CommandStack.Redo();
            undoer.CommandStack.Redo();

            AssertClipsAre(tape, typeof(AlphaClip), typeof(TranslationClip));
        }

        private void AssertClipsAre(Tape tape, params Type[] types)
        {
            Assert.That(tape.Clips.Select(clip => clip.GetType()).SequenceEqual(types));
        }

        private class DummyModerator : IModerator
        {
            public void TriggerAction()
            {
                Execute?.Invoke();
            }

            public event Action Execute;
        }
    }
}