using System.Collections;
using NUnit.Framework;
using UnityEngine.InputSystem;
using UnityEngine.InputSystem.Processors;
using UnityEngine.TestTools;
using UnityEngine.TestTools.Utils;
using UnityEngine.XR.Interaction.Toolkit.Locomotion;
using UnityEngine.XR.Interaction.Toolkit.Locomotion.Movement;
using UnityEngine.XR.Interaction.Toolkit.Locomotion.Turning;
using UnityEngine.XR.Interaction.Toolkit.Utilities;

namespace UnityEngine.XR.Interaction.Toolkit.Tests
{
    [TestFixture]
    class LocomotionInputTests : InputTestFixture
    {
        enum ForwardSource
        {
            Default,
            Camera,
            Controller,
        }

        [TearDown]
        public override void TearDown()
        {
            TestUtilities.DestroyAllSceneObjects();
            base.TearDown();
        }

        [UnityTest]
        public IEnumerator MoveInDefaultDirection()
        {
            return MoveInDirection(ForwardSource.Default);
        }

        [UnityTest]
        public IEnumerator MoveInCameraDirection()
        {
            return MoveInDirection(ForwardSource.Camera);
        }

        [UnityTest]
        public IEnumerator MoveInControllerDirection()
        {
            return MoveInDirection(ForwardSource.Controller);
        }

        IEnumerator MoveInDirection(ForwardSource forwardSource)
        {
            // Create a stick control to serve as the input action source for the move provider
            var gamepad = InputSystem.InputSystem.AddDevice<Gamepad>();

            var asset = ScriptableObject.CreateInstance<InputActionAsset>();
            var actionMap = asset.AddActionMap("Locomotion");
            var action = actionMap.AddAction("Move",
                InputActionType.Value,
                "<Gamepad>/leftStick");

            var inputActionReference = ScriptableObject.CreateInstance<InputActionReference>();
            inputActionReference.Set(action);

            action.Enable();

            var xrOrigin = TestUtilities.CreateXROrigin();
            var rigTransform = xrOrigin.Origin.transform;
            var cameraTransform = xrOrigin.Camera.transform;

            // Rotate the camera to face a different direction than rig forward to test
            // that the move provider will move with respect to a selected forward object.
            cameraTransform.Rotate(0f, 45f, 0f);
            var cameraForward = cameraTransform.forward;
            Assert.That(rigTransform.forward, Is.Not.EqualTo(cameraForward).Using(Vector3ComparerWithEqualsOperator.Instance));

            // Create a controller object to serve as another forward source
            var controllerGO = new GameObject("Controller");
            controllerGO.transform.SetParent(xrOrigin.CameraFloorOffsetObject.transform, false);
            controllerGO.transform.Rotate(0f, -45f, 0f);
            var controllerForward = controllerGO.transform.forward;
            Assert.That(rigTransform.forward, Is.Not.EqualTo(controllerForward).Using(Vector3ComparerWithEqualsOperator.Instance));

            // Config continuous move on XR Origin
            var mediator = xrOrigin.gameObject.AddComponent<LocomotionMediator>();
            mediator.GetComponent<XRBodyTransformer>().xrOrigin = xrOrigin;
            var moveProvider = xrOrigin.gameObject.AddComponent<ContinuousMoveProvider>();
            moveProvider.mediator = mediator;
            moveProvider.leftHandMoveInput.inputActionReference = inputActionReference;
            moveProvider.moveSpeed = 1f;

            switch (forwardSource)
            {
                case ForwardSource.Default:
                    break;
                case ForwardSource.Camera:
                    moveProvider.forwardSource = xrOrigin.Camera.transform;
                    break;
                case ForwardSource.Controller:
                    moveProvider.forwardSource = controllerGO.transform;
                    break;
                default:
                    Assert.Fail($"Unhandled {nameof(ForwardSource)}={forwardSource}");
                    break;
            }

            // See Script Execution Order diagram https://docs.unity3d.com/Manual/ExecutionOrder.html
            // This test will begin after Update() during the yield null/yield WaitForSeconds/yield StartCoroutine stage.
            // The move provider will process input during Update() of the next frame, and scale the move based on Time.deltaTime.
            // After yielding for 1 second with the stick pushed forward, the stick will be released back to center.
            // The move provider will process the release during Update() of the next frame, and should not apply any more movement.

            // Partially push stick directly forward.
            // This tests that the move speed will be scaled by the input magnitude.
            var input = new Vector2(0f, 0.5f);
            var processedInput = new StickDeadzoneProcessor().Process(input);
            Set(gamepad.leftStick, input);
            var startTime = Time.time;

            for (var i = 0; i < 60; ++i) // wait for 60 frames.
                yield return Application.isBatchMode ? null : new WaitForEndOfFrame();

            var actualPosition = rigTransform.position;
            var actualDistance = Vector3.Distance(Vector3.zero, actualPosition);
            var expectedDistance = processedInput.magnitude * moveProvider.moveSpeed * (Time.time - startTime);
            Assert.That(actualDistance, Is.EqualTo(expectedDistance).Within(1e-5f));

            switch (forwardSource)
            {
                case ForwardSource.Default:
                case ForwardSource.Camera:
                    Assert.That(actualPosition, Is.EqualTo(cameraForward * expectedDistance).Using(Vector3ComparerWithEqualsOperator.Instance));
                    break;
                case ForwardSource.Controller:
                    Assert.That(actualPosition, Is.EqualTo(controllerForward * expectedDistance).Using(Vector3ComparerWithEqualsOperator.Instance));
                    break;
                default:
                    Assert.Fail($"Unhandled {nameof(ForwardSource)}={forwardSource}");
                    break;
            }

            // Stop moving
            Set(gamepad.leftStick, Vector2.zero);

            yield return Application.isBatchMode ? null : new WaitForEndOfFrame();

            // ReSharper disable Unity.InefficientPropertyAccess -- Property value accessed after yield
            Assert.That(Vector3.Distance(actualPosition, rigTransform.position), Is.EqualTo(0f));
            // ReSharper restore Unity.InefficientPropertyAccess
        }

        [UnityTest]
        public IEnumerator SmoothTurn()
        {
            // Create a stick control to serve as the input action source for the turn provider
            var gamepad = InputSystem.InputSystem.AddDevice<Gamepad>();

            var asset = ScriptableObject.CreateInstance<InputActionAsset>();
            var actionMap = asset.AddActionMap("Locomotion");
            var action = actionMap.AddAction("Turn",
                InputActionType.Value,
                "<Gamepad>/rightStick");

            var inputActionReference = ScriptableObject.CreateInstance<InputActionReference>();
            inputActionReference.Set(action);

            action.Enable();

            var xrOrigin = TestUtilities.CreateXROrigin();
            var rigTransform = xrOrigin.Origin.transform;

            // Config continuous turn on XR Origin
            var mediator = xrOrigin.gameObject.AddComponent<LocomotionMediator>();
            mediator.GetComponent<XRBodyTransformer>().xrOrigin = xrOrigin;
            var turnProvider = xrOrigin.gameObject.AddComponent<ContinuousTurnProvider>();
            turnProvider.mediator = mediator;
            turnProvider.leftHandTurnInput.inputActionReference = inputActionReference;
            turnProvider.turnSpeed = 60f;

            // Partially push stick directly right.
            // This tests that the turn speed will be scaled by the input magnitude.
            var input = new Vector2(0.5f, 0f);
            var processedInput = new StickDeadzoneProcessor().Process(input);
            Set(gamepad.rightStick, input);
            var startTime = Time.time;

            for (var i = 0; i < 60; ++i) // wait for 60 frames.
                yield return Application.isBatchMode ? null : new WaitForEndOfFrame();

            var turnAmount = processedInput.magnitude * turnProvider.turnSpeed * (Time.time - startTime);
            var actualRotation = rigTransform.rotation;
            Assert.That(actualRotation, Is.EqualTo(Quaternion.Euler(0f, turnAmount, 0f)).Using(QuaternionEqualityComparer.Instance));

            // Stop turning
            Set(gamepad.rightStick, Vector2.zero);

            yield return Application.isBatchMode ? null : new WaitForEndOfFrame();

            // ReSharper disable Unity.InefficientPropertyAccess -- Property value accessed after yield
            Assert.That(actualRotation, Is.EqualTo(rigTransform.rotation).Using(QuaternionEqualityComparer.Instance));
            // ReSharper restore Unity.InefficientPropertyAccess
        }

        [UnityTest]
        public IEnumerator TeleportationMonitorDetectsSnapTurns()
        {
            // Create a stick control to serve as the input action source for the turn provider
            var gamepad = InputSystem.InputSystem.AddDevice<Gamepad>();

            var asset = ScriptableObject.CreateInstance<InputActionAsset>();
            var actionMap = asset.AddActionMap("Locomotion");
            var action = actionMap.AddAction("Turn",
                InputActionType.Value,
                "<Gamepad>/rightStick");

            var inputActionReference = ScriptableObject.CreateInstance<InputActionReference>();
            inputActionReference.Set(action);

            action.Enable();

            var xrOrigin = TestUtilities.CreateXROrigin();
            var rigTransform = xrOrigin.Origin.transform;

            var mediator = xrOrigin.gameObject.AddComponent<LocomotionMediator>();
            mediator.GetComponent<XRBodyTransformer>().xrOrigin = xrOrigin;

            // Config snap turn on XR Origin
            var snapTurnProvider = xrOrigin.gameObject.AddComponent<SnapTurnProvider>();
            snapTurnProvider.mediator = mediator;
            snapTurnProvider.rightHandTurnInput.inputActionReference = inputActionReference;
            snapTurnProvider.enableTurnAround = true;
            snapTurnProvider.debounceTime = 0f;
            var snapTurnStepped = false;
            snapTurnProvider.afterStepLocomotion += _ => snapTurnStepped = true;

            // Config continuous turn on XR Origin
            var continuousTurnProvider = xrOrigin.gameObject.AddComponent<ContinuousTurnProvider>();
            continuousTurnProvider.mediator = mediator;
            continuousTurnProvider.rightHandTurnInput.inputActionReference = inputActionReference;
            continuousTurnProvider.enableTurnAround = true;
            var continuousTurnStepped = false;
            continuousTurnProvider.afterStepLocomotion += _ => continuousTurnStepped = true;

            // Create interactor under the XR Origin
            var interactor = TestUtilities.CreateMockInteractor();
            interactor.transform.SetParent(rigTransform);

            var teleported = false;
            var monitor = new TeleportationMonitor();
            monitor.teleported += (_, _, _) => teleported = true;
            monitor.AddInteractor(interactor);

            // First test with SnapTurnProvider
            snapTurnProvider.enabled = true;
            continuousTurnProvider.enabled = false;

            // Push stick down to trigger turn around.
            Set(gamepad.rightStick, Vector2.down);
            yield return null;

            Assert.That(teleported, Is.True);
            Assert.That(snapTurnStepped, Is.True);
            Assert.That(continuousTurnStepped, Is.False);
            teleported = false;
            snapTurnStepped = false;

            // Stop turning
            Set(gamepad.rightStick, Vector2.zero);
            yield return null;

            // Turn right to trigger snap right
            Set(gamepad.rightStick, Vector2.right);
            yield return null;

            Assert.That(teleported, Is.True);
            Assert.That(snapTurnStepped, Is.True);
            Assert.That(continuousTurnStepped, Is.False);
            teleported = false;
            snapTurnStepped = false;

            // Stop turning
            Set(gamepad.rightStick, Vector2.zero);
            yield return null;

            // Now test with ContinuousTurnProvider
            snapTurnProvider.enabled = false;
            continuousTurnProvider.enabled = true;

            // Push stick down to trigger turn around.
            Set(gamepad.rightStick, Vector2.down);
            yield return null;

            Assert.That(teleported, Is.True);
            Assert.That(snapTurnStepped, Is.False);
            Assert.That(continuousTurnStepped, Is.True);
            teleported = false;
            continuousTurnStepped = false;

            // Stop turning
            Set(gamepad.rightStick, Vector2.zero);
            yield return null;

            // Turn right to trigger partial turn right, which should not trigger a teleport
            // since it only turned a few degrees
            Set(gamepad.rightStick, Vector2.right);
            yield return null;

            Assert.That(teleported, Is.False);
            Assert.That(snapTurnStepped, Is.False);
            Assert.That(continuousTurnStepped, Is.True);
            continuousTurnStepped = false;
        }
    }
}