using System;
using Avalonia.Input.Raw;
using Avalonia.Platform;
using Avalonia.Threading;
using Avalonia.UnitTests;
using Moq;
using Xunit;

namespace Avalonia.Input.UnitTests
{
    public class TouchDeviceTests
    {
        [Fact]
        public void Tapped_Event_Is_Fired_With_Touch()
        {
            using var app = UnitTestApp(new TimeSpan(200));
            var root = new TestRoot();
            var touchDevice = new TouchDevice();

            var isTapped = false;
            var executedTimes = 0;
            root.Tapped += (a, e) =>
            {
                isTapped = true;
                executedTimes++;
            };
            TapOnce(InputManager.Instance, touchDevice, root);
            Assert.True(isTapped);
            Assert.Equal(1, executedTimes);

        }

        [Fact]
        public void DoubleTapped_Event_Is_Fired_With_Touch()
        {
            using var app = UnitTestApp(new TimeSpan(200));
            var root = new TestRoot();
            var touchDevice = new TouchDevice();

            var isDoubleTapped = false;
            var doubleTappedExecutedTimes = 0;
            var tappedExecutedTimes = 0;
            root.DoubleTapped += (a, e) =>
            {
                isDoubleTapped = true;
                doubleTappedExecutedTimes++;
            };
            root.Tapped += (a, e) =>
            {
                tappedExecutedTimes++;
            };
            TapOnce(InputManager.Instance, touchDevice, root);
            TapOnce(InputManager.Instance, touchDevice, root, touchPointId: 1);
            Assert.Equal(1, tappedExecutedTimes);
            Assert.True(isDoubleTapped);
            Assert.Equal(1, doubleTappedExecutedTimes);
        }

        [Theory]
        [InlineData(1)]
        [InlineData(2)]
        [InlineData(3)]
        [InlineData(4)]
        [InlineData(5)]
        public void PointerPressed_Counts_Clicks_Correctly(int clickCount)
        {
            using var app = UnitTestApp(new TimeSpan(200));
            var root = new TestRoot();
            var touchDevice = new TouchDevice();

            var pointerPressedExecutedTimes = 0;
            var pointerPressedClicks = 0;
            root.PointerPressed += (a, e) =>
            {
                pointerPressedClicks = e.ClickCount;
                pointerPressedExecutedTimes++;
            };
            for (int i = 0; i < clickCount; i++)
            {
                TapOnce(InputManager.Instance, touchDevice, root, touchPointId: i);
            }

            Assert.Equal(clickCount, pointerPressedExecutedTimes);
            Assert.Equal(pointerPressedClicks, clickCount);
        }

        [Fact]
        public void DoubleTapped_Not_Fired_When_Click_Too_Late()
        {
            using var app = UnitTestApp(new TimeSpan(0, 0, 0, 0, 20));
            var root = new TestRoot();
            var touchDevice = new TouchDevice();

            var isDoubleTapped = false;
            var doubleTappedExecutedTimes = 0;
            var tappedExecutedTimes = 0;
            root.DoubleTapped += (a, e) =>
            {
                isDoubleTapped = true;
                doubleTappedExecutedTimes++;
            };
            root.Tapped += (a, e) =>
            {
                tappedExecutedTimes++;
            };
            TapOnce(InputManager.Instance, touchDevice, root);
            TapOnce(InputManager.Instance, touchDevice, root, 21, 1);
            Assert.Equal(2, tappedExecutedTimes);
            Assert.False(isDoubleTapped);
            Assert.Equal(0, doubleTappedExecutedTimes);

        }

        [Fact]
        public void DoubleTapped_Not_Fired_When_Second_Click_Is_From_Different_Touch_Contact()
        {
            using var app = UnitTestApp(new TimeSpan(200));
            var root = new TestRoot();
            var touchDevice = new TouchDevice();

            var isDoubleTapped = false;
            var doubleTappedExecutedTimes = 0;
            var tappedExecutedTimes = 0;
            root.DoubleTapped += (a, e) =>
            {
                isDoubleTapped = true;
                doubleTappedExecutedTimes++;
            };
            root.Tapped += (a, e) =>
            {
                tappedExecutedTimes++;
            };
            SendXTouchContactsWithIds(InputManager.Instance, touchDevice, root, RawPointerEventType.TouchBegin, 0, 1);
            SendXTouchContactsWithIds(InputManager.Instance, touchDevice, root, RawPointerEventType.TouchEnd, 0, 1);
            Assert.Equal(2, tappedExecutedTimes);
            Assert.False(isDoubleTapped);
            Assert.Equal(0, doubleTappedExecutedTimes);
        }

        [Fact]
        public void Click_Counting_Should_Work_Correctly_With_Few_Touch_Contacts()
        {
            using var app = UnitTestApp(new TimeSpan(200));

            var root = new TestRoot();
            var touchDevice = new TouchDevice();

            var pointerPressedExecutedTimes = 0;
            var tappedExecutedTimes = 0;
            var isDoubleTapped = false;
            var doubleTappedExecutedTimes = 0;
            root.PointerPressed += (a, e) =>
            {
                pointerPressedExecutedTimes++;
                switch (pointerPressedExecutedTimes)
                {
                    case <= 2:
                        Assert.True(e.ClickCount == 1);
                        break;
                    case 3:
                        Assert.True(e.ClickCount == 2);
                        break;
                    case 4:
                        Assert.True(e.ClickCount == 3);
                        break;
                    case 5:
                        Assert.True(e.ClickCount == 4);
                        break;
                    case 6:
                        Assert.True(e.ClickCount == 5);
                        break;
                    case 7:
                        Assert.True(e.ClickCount == 1);
                        break;
                    case 8:
                        Assert.True(e.ClickCount == 1);
                        break;
                    case 9:
                        Assert.True(e.ClickCount == 2);
                        break;
                    default:
                        break;
                }
            };
            root.DoubleTapped += (a, e) =>
            {
                isDoubleTapped = true;
                doubleTappedExecutedTimes++;
            };
            root.Tapped += (a, e) =>
            {
                tappedExecutedTimes++;
            };
            SendXTouchContactsWithIds(InputManager.Instance, touchDevice, root, RawPointerEventType.TouchBegin, 0, 1);
            SendXTouchContactsWithIds(InputManager.Instance, touchDevice, root, RawPointerEventType.TouchEnd, 0, 1);
            TapOnce(InputManager.Instance, touchDevice, root, touchPointId: 2);
            TapOnce(InputManager.Instance, touchDevice, root, touchPointId: 3);
            TapOnce(InputManager.Instance, touchDevice, root, touchPointId: 4);
            SendXTouchContactsWithIds(InputManager.Instance, touchDevice, root, RawPointerEventType.TouchBegin, 5, 6, 7);
            SendXTouchContactsWithIds(InputManager.Instance, touchDevice, root, RawPointerEventType.TouchEnd, 5, 6, 7);
            TapOnce(InputManager.Instance, touchDevice, root, touchPointId: 8);
            Assert.Equal(6, tappedExecutedTimes);
            Assert.Equal(9, pointerPressedExecutedTimes);
            Assert.True(isDoubleTapped);
            Assert.Equal(3, doubleTappedExecutedTimes);
        }

        private IDisposable UnitTestApp(TimeSpan doubleClickTime = new TimeSpan())
        {
            var unitTestApp = UnitTestApplication.Start(
                new TestServices(inputManager: new InputManager(), dispatcherImpl: Mock.Of<IDispatcherImpl>(x => x.CurrentThreadIsLoopThread == true)));
            var iSettingsMock = new Mock<IPlatformSettings>();
            iSettingsMock.Setup(x => x.GetDoubleTapTime(It.IsAny<PointerType>())).Returns(doubleClickTime);
            iSettingsMock.Setup(x => x.GetDoubleTapSize(It.IsAny<PointerType>())).Returns(new Size(16, 16));
            iSettingsMock.Setup(x => x.GetTapSize(It.IsAny<PointerType>())).Returns(new Size(16, 16));
            AvaloniaLocator.CurrentMutable.BindToSelf(this)
               .Bind<IPlatformSettings>().ToConstant(iSettingsMock.Object);
            return unitTestApp;
        }
        
        private static void SendXTouchContactsWithIds(IInputManager inputManager, TouchDevice device, IInputRoot root, RawPointerEventType type, params long[] touchPointIds)
        {
            for (int i = 0; i < touchPointIds.Length; i++)
            {
                inputManager.ProcessInput(new RawPointerEventArgs(device, 0,
                                                              root,
                                                              type,
                                                              new Point(0, 0),
                                                              RawInputModifiers.None)
                {
                    RawPointerId = touchPointIds[i]
                });
            }
        }


        private static void TapOnce(IInputManager inputManager, TouchDevice device, IInputRoot root, ulong timestamp = 0, long touchPointId = 0)
        {
            inputManager.ProcessInput(new RawPointerEventArgs(device, timestamp,
                                               root,
                                               RawPointerEventType.TouchBegin,
                                               new Point(0, 0),
                                               RawInputModifiers.None)
            {
                RawPointerId = touchPointId
            });
            inputManager.ProcessInput(new RawPointerEventArgs(device, timestamp,
                                                root,
                                                RawPointerEventType.TouchEnd,
                                                new Point(0, 0),
                                                RawInputModifiers.None)
            {
                RawPointerId = touchPointId
            });
        }
    }
}