// Crest Ocean System

// Copyright 2020 Wave Harmonic Ltd

using UnityEngine;

namespace Crest.Examples
{
    [RequireComponent(typeof(Rigidbody))]
    public class ShipAnchor : MonoBehaviour
    {
        public float _springConstant = 10000f;
        public float _springConstantRotational = 10000000f;

        Rigidbody _rb;
        Vector3 _anchorPosWS;
        Vector3 _anchorForwardWS;

        private void Start()
        {
            _anchorPosWS = transform.position;
            _anchorForwardWS = transform.forward;
            _anchorPosWS.y = _anchorForwardWS.y = 0f;

            _rb = GetComponent<Rigidbody>();
        }

        private void FixedUpdate()
        {
            var pos = transform.position;
            pos.y = 0f;
            var force = (_anchorPosWS - pos) * _springConstant;
            _rb.AddForce(force);

            var forward = transform.forward;
            forward.y = 0f;
            var torque = -Vector3.Cross(_anchorForwardWS, forward) * _springConstantRotational;
            _rb.AddTorque(torque);
        }
    }
}