#if !NEOFPS_FORCE_QUALITY && (UNITY_ANDROID || UNITY_IOS || UNITY_TIZEN || (UNITY_WSA && NETFX_CORE) || NEOFPS_FORCE_LIGHTWEIGHT)
#define NEOFPS_LIGHTWEIGHT
#endif

using UnityEngine;
using NeoFPS.CharacterMotion.MotionData;
using NeoFPS.CharacterMotion.Parameters;
using NeoSaveGames.Serialization;

namespace NeoFPS.CharacterMotion.States
{
    [MotionGraphElement("Swimming/Swim Surface (Smooth)", "SwimSurface")]
    [HelpURL("https://docs.neofps.com/manual/motiongraphref-mgs-swimsmoothsurfacestate.html")]
    public class SwimSmoothSurfaceState : MotionGraphState
    {
        [SerializeField, Tooltip("The transform parameter which contains the transform of the water zone object")]
        private TransformParameter m_WaterZoneParameter = null;
        [SerializeField, Tooltip("The top movement speed (for keyboard input or max analog input)")]
        private FloatDataReference m_SwimSpeed = new FloatDataReference(5f);
        [SerializeField, Tooltip("The maximum acceleration")]
        private FloatDataReference m_Acceleration = new FloatDataReference(25f);
        [SerializeField, Tooltip("The multiplier applied to the max movement speed and acceleration when strafing")]
        private FloatDataReference m_StrafeMultiplier = new FloatDataReference(0.75f);
        [SerializeField, Tooltip("The multiplier applied to the max movement speed and acceleration when moving in reverse")]
        private FloatDataReference m_ReverseMultiplier = new FloatDataReference(0.5f);
        [SerializeField, Tooltip("The multiplier applied to the acceleration when no input is detected")]
        private FloatDataReference m_IdleMultiplier = new FloatDataReference(0.5f);
        [SerializeField, Tooltip("The length of time a swimming stroke lasts (unscaled).")]
        private float m_TargetHeadHeight = 0.35f;

        private const float k_TinyValue = 0.001f;

        private Vector3 m_OutMoveVector = Vector3.zero;
        private Transform m_WaterZoneTransform = null;
        private IWaterZone m_WaterZone = null;
        private Vector3 m_MotorAcceleration = Vector3.zero;
        private Vector3 m_FlowAcceleration = Vector3.zero;
        private Vector3 m_FlowVelocity = Vector3.zero;
        private float m_LastSurfaceHeight = float.NaN;

        public override Vector3 moveVector
        {
            get { return m_OutMoveVector; }
        }

        public override bool applyGravity
        {
            get { return false; }
        }

        public override bool applyGroundingForce
        {
            get { return false; }
        }

        public override bool ignorePlatformMove
        {
            get { return false; }
        }

        public override void OnValidate()
        {
            base.OnValidate();
            m_TargetHeadHeight = Mathf.Clamp(m_TargetHeadHeight, 0.05f, 1f);
            m_SwimSpeed.ClampValue(0.1f, 50f);
            m_StrafeMultiplier.ClampValue(0f, 2f);
            m_ReverseMultiplier.ClampValue(0f, 2f);
            m_IdleMultiplier.ClampValue(0f, 1f);
            m_Acceleration.ClampValue(0f, 100f);
        }

        public override void OnEnter()
        {
            base.OnEnter();
        }

        public override void OnExit()
        {
            base.OnExit();
            m_OutMoveVector = Vector3.zero;
            m_MotorAcceleration = Vector3.zero;
            m_FlowAcceleration = Vector3.zero;
            m_FlowVelocity = Vector3.zero;
            m_LastSurfaceHeight = float.NaN;
        }

        void CheckWaterZone()
        {
            // Get the water zone
            if (m_WaterZoneParameter != null)
            {
                if (m_WaterZoneTransform != m_WaterZoneParameter.value)
                {
                    m_WaterZoneTransform = m_WaterZoneParameter.value;
                    if (m_WaterZoneTransform != null)
                        m_WaterZone = m_WaterZoneTransform.GetComponent<IWaterZone>();
                }
            }
        }

        public override void Update()
        {
            base.Update();

            CheckWaterZone();

            m_OutMoveVector = Vector3.zero;

            // Get movement axes
            Vector3 right = characterController.right;
            Vector3 forward = characterController.forward;

            // Get the surface info
            float targetHeightOffset = 0f;
            WaterSurfaceInfo surface = new WaterSurfaceInfo(Vector3.up, 0f);
            if (m_WaterZone != null)
            {
                // Get the water surface from the top sphere of the character
                var highest = WaterZoneHelpers.GetHighestSphereCenter(controller);
                surface = m_WaterZone.SurfaceInfoAtPosition(highest);

                // Get the offset from the current height above the surface to the target
                float currentHeight = highest.y + characterController.radius;
                float targetHeight = surface.height + m_TargetHeadHeight;
                targetHeightOffset = targetHeight - currentHeight;

                // Get surface movement (and clamp speed)
                if (!float.IsNaN(m_LastSurfaceHeight))
                {
                    float surfaceMatchOffset = surface.height - m_LastSurfaceHeight;
                    targetHeightOffset -= surfaceMatchOffset;
                    m_OutMoveVector = Vector3.up * surfaceMatchOffset;
                }
                m_LastSurfaceHeight = surface.height;
            }

            // Tilt the movement axes to the surface
            if (surface.normal != Vector3.up)
            {
                var p = new Plane(surface.normal, 0f);

                // Uses plane raycasts to ensure vertical direction is still the same
                float vOffset = 0f;
                p.Raycast(new Ray(forward, Vector3.up), out vOffset);
                forward = (forward + Vector3.up * vOffset).normalized;
                p.Raycast(new Ray(right, Vector3.up), out vOffset);
                forward = (right + Vector3.up * vOffset).normalized;
            }

            // Get the input direction multipliers
            bool idle = controller.inputMoveScale < 0.02f;
            float directionMultiplier = m_IdleMultiplier.value;
            if (!idle)
            {
                // Get the input vector
                Vector2 input = controller.inputMoveDirection;

                // Apply axis multipliers
                input.x *= m_StrafeMultiplier.value;
                if (input.y < 0f)
                    input.y *= m_ReverseMultiplier.value;

                // Direction multiplier is new magnitude
                directionMultiplier = input.magnitude;
            }
            
            // Get target input velocity
            Vector3 targetVelocity = Vector3.zero;
            if (!idle)
            {
                // Get target velocity
                float topSpeed = m_SwimSpeed.value * directionMultiplier * controller.inputMoveScale;
                targetVelocity += forward * (controller.inputMoveDirection.y * topSpeed);
                targetVelocity += right * (controller.inputMoveDirection.x * topSpeed);
            }

            // Accelerate if required
            float acceleration = m_Acceleration.value;
            if (acceleration < k_TinyValue)
                m_OutMoveVector += targetVelocity;
            else
            {
                var currentVelocity = characterController.velocity - m_FlowVelocity - (m_OutMoveVector / Time.deltaTime);
                if (targetVelocity != currentVelocity)
                {
                    // Accelerate the velocity
                    m_OutMoveVector += Vector3.SmoothDamp(currentVelocity, targetVelocity, ref m_MotorAcceleration, 0.5f, acceleration) * Time.deltaTime;
                }
            }

            // Lerp to the desired head offset (might want to make the magic numbers serialized properties)
            targetHeightOffset *= 0.15f;
            if ((targetHeightOffset < 0f && m_OutMoveVector.y > targetHeightOffset) ||
                (targetHeightOffset > 0f && m_OutMoveVector.y < targetHeightOffset))
                m_OutMoveVector.y = Mathf.Lerp(m_OutMoveVector.y, targetHeightOffset, 0.25f);

            // Add water flow
            if (m_WaterZone != null)
            {
                m_FlowVelocity = Vector3.SmoothDamp(
                    m_FlowVelocity,
                    m_WaterZone.FlowAtPosition(controller.localTransform.position + characterController.up * characterController.radius),
                    ref m_FlowAcceleration,
                    0.5f,
                    m_Acceleration.value
                    );
            }
            m_OutMoveVector += m_FlowVelocity * Time.deltaTime;
        }

        public override void CheckReferences(IMotionGraphMap map)
        {
            m_WaterZoneParameter = map.Swap(m_WaterZoneParameter);
            m_SwimSpeed.CheckReference(map);
            m_Acceleration.CheckReference(map);
            m_StrafeMultiplier.CheckReference(map);
            m_ReverseMultiplier.CheckReference(map);
            m_IdleMultiplier.CheckReference(map);
            base.CheckReferences(map);
        }


        #region SAVE / LOAD

        private static readonly NeoSerializationKey k_AccelerationKey = new NeoSerializationKey("acceleration");
        private static readonly NeoSerializationKey k_OutMoveVectorKey = new NeoSerializationKey("move");
        private static readonly NeoSerializationKey k_FlowAccelerationKey = new NeoSerializationKey("flowA");
        private static readonly NeoSerializationKey k_FlowVelocityKey = new NeoSerializationKey("flowV");
        private static readonly NeoSerializationKey k_SurfaceHeightKey = new NeoSerializationKey("surface");

        public override void WriteProperties(INeoSerializer writer)
        {
            base.WriteProperties(writer);
            writer.WriteValue(k_AccelerationKey, m_MotorAcceleration);
            writer.WriteValue(k_OutMoveVectorKey, m_OutMoveVector);
            writer.WriteValue(k_FlowAccelerationKey, m_FlowAcceleration);
            writer.WriteValue(k_FlowVelocityKey, m_FlowVelocity);
            writer.WriteValue(k_SurfaceHeightKey, m_LastSurfaceHeight);
        }

        public override void ReadProperties(INeoDeserializer reader)
        {
            base.ReadProperties(reader);
            reader.TryReadValue(k_AccelerationKey, out m_MotorAcceleration, m_MotorAcceleration);
            reader.TryReadValue(k_OutMoveVectorKey, out m_OutMoveVector, m_OutMoveVector);
            reader.TryReadValue(k_FlowAccelerationKey, out m_FlowAcceleration, m_FlowAcceleration);
            reader.TryReadValue(k_FlowVelocityKey, out m_FlowVelocity, m_FlowVelocity);
            reader.TryReadValue(k_SurfaceHeightKey, out m_LastSurfaceHeight, m_LastSurfaceHeight);
        }

        #endregion
    }
}