using UnityEngine;

namespace AxelF {

sealed public class Occlusion : MonoBehaviour {
    public Parameters.OcclusionParams occlusion;
    public Parameters.SpatialParams spatial;

    AudioSource _source;
    AudioLowPassFilter _lowPassFilter;
    AudioHighPassFilter _highPassFilter;
    OcclusionSettings _settings;
    int _lastFrame;
    float _target;
    float _current;

    public float GetTarget() { return _target; }
    public float GetCurrent() { return _current; }

    void OnEnable() {
        if (_source == null)
            _source = GetComponent<AudioSource>();
        if (_lowPassFilter == null)
            _lowPassFilter = GetComponent<AudioLowPassFilter>();
        if (_highPassFilter == null)
            _highPassFilter = GetComponent<AudioHighPassFilter>();
        if (_settings == null)
            _settings = OcclusionSettings.instance;
        _lastFrame = -1;
        Test(Mathf.Infinity);
    }

    void LateUpdate() {
        Test(Time.deltaTime);
    }

    void Test(float dt) {
        if (_lastFrame != Time.frameCount) {
            _lastFrame = Time.frameCount;
            var l = Heartbeat.listenerTransform;
            if (l != null) {
                var lpos = l.position;
                Vector3 d = transform.position - lpos;
                if (occlusion.function == OcclusionFunction.Distance) {
                    if (Mathf.Approximately(spatial.distance.max - spatial.distance.min, 0f))
                        _target = d.magnitude >= spatial.distance.max ? 0f : 1f;
                    else
                        _target = 1f - Mathf.Clamp01(
                            Mathf.Max(0f, d.magnitude - spatial.distance.min) /
                            (spatial.distance.max - spatial.distance.min));
                } else if (occlusion.function == OcclusionFunction.Slapback) {
                    if (Mathf.Approximately(spatial.distance.max - spatial.distance.min, 0f))
                        _target = d.magnitude >= spatial.distance.max ? 0f : 1f;
                    else
                        _target = Mathf.Clamp01(
                            Mathf.Max(0f, d.magnitude - spatial.distance.min) /
                            (spatial.distance.max - spatial.distance.min));
                } else if (occlusion.function == OcclusionFunction.Raycast &&
                        Physics.Raycast(
                            lpos, d.normalized, d.magnitude, _settings.layerMask,
                            QueryTriggerInteraction.Ignore))
                    _target = 0f;
                else
                    _target = 1f;
            }
        }
        _current = Mathf.Lerp(_current, _target, dt * 8f);
        _lowPassFilter.cutoffFrequency =
            _settings.lowPassRange.min +
            (_settings.lowPassRange.max - _settings.lowPassRange.min) * _current;
        _highPassFilter.cutoffFrequency =
            _settings.highPassRange.min +
            (_settings.highPassRange.max - _settings.highPassRange.min) * (1f - _current);
    }
}

} // AxelF