// Crest Ocean System

// Copyright 2020 Wave Harmonic Ltd

using UnityEngine;

namespace Crest.Examples
{

    public class LerpCam : 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

        [SerializeField] float _lerpAlpha = 0.1f;
        [SerializeField] Transform _targetPos = null;
        [SerializeField] Transform _targetLookatPos = null;
        [SerializeField] float _lookatOffset = 5f;
        [SerializeField] float _minHeightAboveWater = 0.5f;

        SampleHeightHelper _sampleHeightHelper = new SampleHeightHelper();

        void Update()
        {
            if (OceanRenderer.Instance == null || _targetPos == null)
            {
                return;
            }

            _sampleHeightHelper.Init(transform.position, 0f);
            _sampleHeightHelper.Sample(out var h);

            var targetPos = _targetPos.position;
            targetPos.y = Mathf.Max(targetPos.y, h + _minHeightAboveWater);

            transform.position = Vector3.Lerp(transform.position, targetPos, _lerpAlpha * OceanRenderer.Instance.DeltaTime * 60f);
            transform.LookAt(_targetLookatPos.position + _lookatOffset * Vector3.up);
        }
    }
}