using RebootKit.Engine.Foundation;
using UnityEngine;

namespace RebootReality.jelycho.Player {
    public class CameraSpring : MonoBehaviour {
        [Min(0.01f), SerializeField] float m_HalfLife = 0.075f;
        [SerializeField] float m_Frequency = 10.0f;
        [SerializeField] float m_ForwardAngularDisplacement = 1.0f;
        [SerializeField] float m_SidewaysAngularDisplacement = 1.0f;
        [SerializeField] float m_HeightAngularDisplacement = 2.0f;
        
        Vector3 m_SpringPosition;
        Vector3 m_SpringVelocity;

        public void Initialize() {
            m_SpringPosition = transform.position;
            m_SpringVelocity = Vector3.zero;
        }

        public void UpdateSpring(float deltaTime, Vector3 up, Vector3 right, Vector3 forward) {
            MathUtility.Spring(ref m_SpringPosition,
                               ref m_SpringVelocity,
                               transform.position,
                               m_HalfLife,
                               m_Frequency,
                               deltaTime);

            Vector3 localSpringPosition = m_SpringPosition - transform.position;
            float springHeight = Vector3.Dot(localSpringPosition, up);
            float springForward = Vector3.Dot(localSpringPosition, forward);
            float springSideways = Vector3.Dot(localSpringPosition, right);

            float pitch = -springHeight * m_HeightAngularDisplacement + -springForward * m_ForwardAngularDisplacement;
            transform.localEulerAngles = new Vector3(pitch,
                                                     0.0f,
                                                     springSideways * m_SidewaysAngularDisplacement);
        }
    }
}