// Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
// See the LICENCE file in the repository root for full licence text.

using System.Linq;
using NUnit.Framework;
using osu.Framework.Graphics;
using osu.Framework.Graphics.Containers;
using osu.Framework.Input;
using osu.Framework.Input.Bindings;
using osu.Framework.Input.Events;
using osu.Framework.Testing;
using osu.Game.Screens.Play;
using osu.Game.Tests.Visual;
using osuTK;

namespace osu.Game.Rulesets.Osu.Tests
{
    [TestFixture]
    public partial class TestSceneTouchInput : OsuManualInputManagerTestScene
    {
        private TestActionKeyCounter leftKeyCounter = null!;

        private TestActionKeyCounter rightKeyCounter = null!;

        private OsuInputManager osuInputManager = null!;

        [SetUpSteps]
        public void SetUpSteps()
        {
            releaseAllTouches();

            AddStep("Create tests", () =>
            {
                Child = osuInputManager = new OsuInputManager(new OsuRuleset().RulesetInfo)
                {
                    Child = new Container
                    {
                        Anchor = Anchor.Centre,
                        Origin = Anchor.Centre,
                        Children = new Drawable[]
                        {
                            leftKeyCounter = new TestActionKeyCounter(OsuAction.LeftButton),
                            rightKeyCounter = new TestActionKeyCounter(OsuAction.RightButton) { Margin = new MarginPadding { Left = 150 } }
                        },
                    }
                };
            });
        }

        [Test]
        public void TestSimpleInput()
        {
            beginTouch(TouchSource.Touch1);

            assertKeyCounter(1, 0);
            expectPressedCurrently(OsuAction.LeftButton);

            beginTouch(TouchSource.Touch2);

            assertKeyCounter(1, 1);
            expectPressedCurrently(OsuAction.LeftButton);
            expectPressedCurrently(OsuAction.RightButton);

            // Subsequent touches should be ignored.
            beginTouch(TouchSource.Touch3);
            beginTouch(TouchSource.Touch4);

            assertKeyCounter(1, 1);

            expectPressedCurrently(OsuAction.LeftButton);
            expectPressedCurrently(OsuAction.RightButton);

            assertKeyCounter(1, 1);
        }

        [Test]
        public void TestAlternatingInput()
        {
            beginTouch(TouchSource.Touch1);

            assertKeyCounter(1, 0);
            expectPressedCurrently(OsuAction.LeftButton);

            beginTouch(TouchSource.Touch2);

            assertKeyCounter(1, 1);
            expectPressedCurrently(OsuAction.LeftButton);
            expectPressedCurrently(OsuAction.RightButton);

            endTouch(TouchSource.Touch1);

            assertKeyCounter(1, 1);
            expectPressedCurrently(OsuAction.RightButton);

            beginTouch(TouchSource.Touch1);

            assertKeyCounter(2, 1);
            expectPressedCurrently(OsuAction.LeftButton);
            expectPressedCurrently(OsuAction.RightButton);

            endTouch(TouchSource.Touch2);

            assertKeyCounter(2, 1);
            expectPressedCurrently(OsuAction.LeftButton);

            beginTouch(TouchSource.Touch2);

            assertKeyCounter(2, 2);
            expectPressedCurrently(OsuAction.LeftButton);
            expectPressedCurrently(OsuAction.RightButton);
        }

        [Test]
        public void TestPressReleaseOrder()
        {
            beginTouch(TouchSource.Touch1);
            beginTouch(TouchSource.Touch2);
            beginTouch(TouchSource.Touch3);

            assertKeyCounter(1, 1);
            expectPressedCurrently(OsuAction.LeftButton);
            expectPressedCurrently(OsuAction.RightButton);

            // Touch 3 was ignored, but let's ensure that if 1 or 2 are released, 3 will be handled a second attempt.
            endTouch(TouchSource.Touch1);

            assertKeyCounter(1, 1);
            expectPressedCurrently(OsuAction.RightButton);

            endTouch(TouchSource.Touch3);

            assertKeyCounter(1, 1);
            expectPressedCurrently(OsuAction.RightButton);

            beginTouch(TouchSource.Touch3);

            assertKeyCounter(2, 1);
            expectPressedCurrently(OsuAction.LeftButton);
            expectPressedCurrently(OsuAction.RightButton);
        }

        [Test]
        public void TestWithDisallowedUserCursor()
        {
            beginTouch(TouchSource.Touch1);

            assertKeyCounter(1, 0);
            expectPressedCurrently(OsuAction.LeftButton);

            beginTouch(TouchSource.Touch2);

            assertKeyCounter(1, 1);
            expectPressedCurrently(OsuAction.RightButton);

            // Subsequent touches should be ignored.
            beginTouch(TouchSource.Touch3);
            beginTouch(TouchSource.Touch4);

            assertKeyCounter(1, 1);

            expectPressedCurrently(OsuAction.LeftButton);
            expectPressedCurrently(OsuAction.RightButton);

            assertKeyCounter(1, 1);
        }

        private void beginTouch(TouchSource source, Vector2? screenSpacePosition = null) =>
            AddStep($"Begin touch for {source}", () => InputManager.BeginTouch(new Touch(source, screenSpacePosition ?? osuInputManager.ScreenSpaceDrawQuad.Centre)));

        private void endTouch(TouchSource source) =>
            AddStep($"Release touch for {source}", () => InputManager.EndTouch(new Touch(source, osuInputManager.ScreenSpaceDrawQuad.Centre)));

        private void assertKeyCounter(int left, int right)
        {
            AddAssert($"The left key was pressed {left} times", () => leftKeyCounter.CountPresses, () => Is.EqualTo(left));
            AddAssert($"The right key was pressed {right} times", () => rightKeyCounter.CountPresses, () => Is.EqualTo(right));
        }

        private void releaseAllTouches()
        {
            AddStep("Release all touches", () =>
            {
                foreach (TouchSource source in InputManager.CurrentState.Touch.ActiveSources)
                    InputManager.EndTouch(new Touch(source, osuInputManager.ScreenSpaceDrawQuad.Centre));
            });
        }

        private void expectPressedCurrently(OsuAction action) => AddAssert($"Is pressing {action}", () => osuInputManager.PressedActions.Contains(action));

        public partial class TestActionKeyCounter : KeyCounter, IKeyBindingHandler<OsuAction>
        {
            public OsuAction Action { get; }

            public TestActionKeyCounter(OsuAction action)
                : base(action.ToString())
            {
                Action = action;
            }

            public bool OnPressed(KeyBindingPressEvent<OsuAction> e)
            {
                if (e.Action == Action)
                {
                    IsLit = true;
                    Increment();
                }

                return false;
            }

            public void OnReleased(KeyBindingReleaseEvent<OsuAction> e)
            {
                if (e.Action == Action) IsLit = false;
            }
        }
    }
}