using UnityEngine;
#if UNITY_EDITOR
using UnityEditor;
#endif

[ExecuteAlways]
[RequireComponent(typeof(Light))]
public class MenuLightAnimator : MonoBehaviour
{
    [Header("Rotation")]
    // Yaw oscillates around the base direction rather than spinning all the way around, so the
    // light never swings past the wall's edge into a back-lighting angle that goes dark.
    public float yawAmplitude = 35f;
    public float yawSpeed = 0.2f;
    public float pitchAmplitude = 10f;
    public float pitchSpeed = 0.35f;

    [Header("Intensity & Color")]
    public float baseIntensity = 1.1f;
    public float intensityPulseAmount = 0.25f;
    public float pulseSpeed = 0.6f;
    public Color colorA = new Color(1f, 0.96f, 0.86f);
    public Color colorB = new Color(0.8f, 0.88f, 1f);

    Light _light;
    float _baseYaw;
    float _basePitch;

    void OnEnable()
    {
        _light = GetComponent<Light>();
        Vector3 e = transform.eulerAngles;
        _baseYaw = e.y;
        _basePitch = e.x;
#if UNITY_EDITOR
        EditorApplication.update -= EditorTick;
        if (!Application.isPlaying)
            EditorApplication.update += EditorTick;
#endif
    }

    void OnDisable()
    {
#if UNITY_EDITOR
        EditorApplication.update -= EditorTick;
#endif
    }

#if UNITY_EDITOR
    void EditorTick()
    {
        if (Application.isPlaying) return;
        Animate((float)EditorApplication.timeSinceStartup);
    }
#endif

    void Update()
    {
        if (!Application.isPlaying) return;
        Animate(Time.time);
    }

    void Animate(float time)
    {
        float yaw = _baseYaw + Mathf.Sin(time * yawSpeed) * yawAmplitude;
        float pitch = _basePitch + Mathf.Sin(time * pitchSpeed + 1.3f) * pitchAmplitude;
        transform.rotation = Quaternion.Euler(pitch, yaw, 0f);

        if (_light == null) _light = GetComponent<Light>();
        _light.intensity = baseIntensity + Mathf.Sin(time * pulseSpeed) * intensityPulseAmount;
        float colorT = (Mathf.Sin(time * pulseSpeed * 0.5f) + 1f) * 0.5f;
        _light.color = Color.Lerp(colorA, colorB, colorT);
    }
}