// Crest Ocean System

// Copyright 2020 Wave Harmonic Ltd

#if CREST_UNITY_INPUT && ENABLE_INPUT_SYSTEM
#define INPUT_SYSTEM_ENABLED
#endif

using UnityEngine;
#if INPUT_SYSTEM_ENABLED
using UnityEngine.InputSystem;
#endif
#if ENABLE_VR && ENABLE_VR_MODULE
using UnityEngine.XR;
#endif

namespace Crest.Examples
{
    /// <summary>
    /// A simple and dumb camera script that can be controlled using WASD and the mouse.
    /// </summary>
    public class CamController : MonoBehaviour
    {
        /// <summary>
        /// The version of this asset. Can be used to migrate across versions. This value should
        /// only be changed when the editor upgrades the version.
        /// </summary>
        [SerializeField, HideInInspector]
#pragma warning disable 414
        int _version = 0;
#pragma warning restore 414

        public float linSpeed = 10f;
        public float rotSpeed = 70f;

        public bool simForwardInput = false;
        public bool _requireLMBToMove = false;

        Vector2 _lastMousePos = -Vector2.one;
        bool _dragging = false;

        public float _fixedDt = 1 / 60f;

        Transform _targetTransform;

#pragma warning disable CS0108
        // In editor we need to use "new" to suppress warning but then gives warning when building so use pragma instead.
        Camera camera;
#pragma warning restore CS0108

        [Space(10)]

        [SerializeField]
        DebugFields _debug = new DebugFields();

        [System.Serializable]
        class DebugFields
        {
            [Tooltip("Allows the camera to roll (rotating on the z axis).")]
            public bool _enableCameraRoll = false;

            [Tooltip("Disables the XR occlusion mesh for debugging purposes. Only works with legacy XR.")]
            public bool _disableOcclusionMesh = false;

            [Tooltip("Sets the XR occlusion mesh scale. Useful for debugging refractions. Only works with legacy XR."), UnityEngine.Range(1f, 2f)]
            public float _occlusionMeshScale = 1f;
        }

        void Awake()
        {
            _targetTransform = transform;

            if (!TryGetComponent(out camera))
            {
                enabled = false;
                return;
            }

#if ENABLE_VR && ENABLE_VR_MODULE
            if (XRSettings.enabled)
            {
                // Seems like the best place to put this for now. Most XR debugging happens using this component.
                // @FixMe: useOcclusionMesh doesn't work anymore. Might be a Unity bug.
                XRSettings.useOcclusionMesh = !_debug._disableOcclusionMesh;
                XRSettings.occlusionMaskScale = _debug._occlusionMeshScale;
            }
#endif
        }

        void Update()
        {
            float dt = Time.deltaTime;
            if (_fixedDt > 0f)
                dt = _fixedDt;

            UpdateMovement(dt);

#if ENABLE_VR && ENABLE_VR_MODULE
            // These aren't useful and can break for XR hardware.
            if (!XRSettings.enabled || XRSettings.loadedDeviceName.Contains("MockHMD"))
#endif
            {
                UpdateDragging(dt);
                UpdateKillRoll();
            }

#if ENABLE_VR && ENABLE_VR_MODULE
            if (XRSettings.enabled)
            {
                // Check if property has changed.
                if (XRSettings.useOcclusionMesh == _debug._disableOcclusionMesh)
                {
                    // @FixMe: useOcclusionMesh doesn't work anymore. Might be a Unity bug.
                    XRSettings.useOcclusionMesh = !_debug._disableOcclusionMesh;
                }

                XRSettings.occlusionMaskScale = _debug._occlusionMeshScale;
            }
#endif
        }

        void UpdateMovement(float dt)
        {
            // New input system works even when game view is not focused.
            if (!Application.isFocused)
            {
                return;
            }

#if INPUT_SYSTEM_ENABLED
            if (!Mouse.current.leftButton.isPressed && _requireLMBToMove) return;
            float forward = (Keyboard.current.wKey.isPressed ? 1 : 0) - (Keyboard.current.sKey.isPressed ? 1 : 0);
#else
            if (!Input.GetMouseButton(0) && _requireLMBToMove) return;
            float forward = (Input.GetKey(KeyCode.W) ? 1 : 0) - (Input.GetKey(KeyCode.S) ? 1 : 0);
#endif
            if (simForwardInput)
            {
                forward = 1f;
            }

            _targetTransform.position += linSpeed * _targetTransform.forward * forward * dt;
            var speed = linSpeed;

#if INPUT_SYSTEM_ENABLED
            if (Keyboard.current.leftShiftKey.isPressed)
#else
            if (Input.GetKey(KeyCode.LeftShift))
#endif
            {
                speed *= 3f;
            }

            _targetTransform.position += speed * _targetTransform.forward * forward * dt;
            //_transform.position += linSpeed * _transform.right * Input.GetAxis( "Horizontal" ) * dt;
#if INPUT_SYSTEM_ENABLED
            _targetTransform.position += linSpeed * _targetTransform.up * (Keyboard.current.eKey.isPressed ? 1 : 0) * dt;
            _targetTransform.position -= linSpeed * _targetTransform.up * (Keyboard.current.qKey.isPressed ? 1 : 0) * dt;
            _targetTransform.position -= linSpeed * _targetTransform.right * (Keyboard.current.aKey.isPressed ? 1 : 0) * dt;
            _targetTransform.position += linSpeed * _targetTransform.right * (Keyboard.current.dKey.isPressed ? 1 : 0) * dt;
            _targetTransform.position += speed * _targetTransform.up * (Keyboard.current.eKey.isPressed ? 1 : 0) * dt;
            _targetTransform.position -= speed * _targetTransform.up * (Keyboard.current.qKey.isPressed ? 1 : 0) * dt;
            _targetTransform.position -= speed * _targetTransform.right * (Keyboard.current.aKey.isPressed ? 1 : 0) * dt;
            _targetTransform.position += speed * _targetTransform.right * (Keyboard.current.dKey.isPressed ? 1 : 0) * dt;
#else
            _targetTransform.position += linSpeed * _targetTransform.up * (Input.GetKey(KeyCode.E) ? 1 : 0) * dt;
            _targetTransform.position -= linSpeed * _targetTransform.up * (Input.GetKey(KeyCode.Q) ? 1 : 0) * dt;
            _targetTransform.position -= linSpeed * _targetTransform.right * (Input.GetKey(KeyCode.A) ? 1 : 0) * dt;
            _targetTransform.position += linSpeed * _targetTransform.right * (Input.GetKey(KeyCode.D) ? 1 : 0) * dt;
            _targetTransform.position += speed * _targetTransform.up * (Input.GetKey(KeyCode.E) ? 1 : 0) * dt;
            _targetTransform.position -= speed * _targetTransform.up * (Input.GetKey(KeyCode.Q) ? 1 : 0) * dt;
            _targetTransform.position -= speed * _targetTransform.right * (Input.GetKey(KeyCode.A) ? 1 : 0) * dt;
            _targetTransform.position += speed * _targetTransform.right * (Input.GetKey(KeyCode.D) ? 1 : 0) * dt;
#endif
            {
                float rotate = 0f;
#if INPUT_SYSTEM_ENABLED
                rotate += (Keyboard.current.rightArrowKey.isPressed ? 1 : 0);
                rotate -= (Keyboard.current.leftArrowKey.isPressed ? 1 : 0);
#else
                rotate += (Input.GetKey(KeyCode.RightArrow) ? 1 : 0);
                rotate -= (Input.GetKey(KeyCode.LeftArrow) ? 1 : 0);
#endif

                rotate *= 5f;
                Vector3 ea = _targetTransform.eulerAngles;
                ea.y += 0.1f * rotSpeed * rotate * dt;
                _targetTransform.eulerAngles = ea;
            }
        }

        void UpdateDragging(float dt)
        {
            // New input system works even when game view is not focused.
            if (!Application.isFocused)
            {
                return;
            }

            Vector2 mousePos =
#if INPUT_SYSTEM_ENABLED
                Mouse.current.position.ReadValue();
#else
                Input.mousePosition;
#endif

            var wasLeftMouseButtonPressed =
#if INPUT_SYSTEM_ENABLED
                Mouse.current.leftButton.wasPressedThisFrame;
#else
                Input.GetMouseButtonDown(0);
#endif

            if (!_dragging && wasLeftMouseButtonPressed && camera.rect.Contains(camera.ScreenToViewportPoint(mousePos)) &&
                !Crest.OceanDebugGUI.OverGUI(mousePos))
            {
                _dragging = true;
                _lastMousePos = mousePos;
            }
#if INPUT_SYSTEM_ENABLED
            if (_dragging && Mouse.current.leftButton.wasReleasedThisFrame)
#else
            if (_dragging && Input.GetMouseButtonUp(0))
#endif
            {
                _dragging = false;
                _lastMousePos = -Vector2.one;
            }

            if (_dragging)
            {
                Vector2 delta = mousePos - _lastMousePos;

                Vector3 ea = _targetTransform.eulerAngles;
                ea.x += -0.1f * rotSpeed * delta.y * dt;
                ea.y += 0.1f * rotSpeed * delta.x * dt;
                _targetTransform.eulerAngles = ea;

                _lastMousePos = mousePos;
            }
        }

        void UpdateKillRoll()
        {
            if (_debug._enableCameraRoll) return;
            Vector3 ea = _targetTransform.eulerAngles;
            ea.z = 0f;
            transform.eulerAngles = ea;
        }
    }
}