using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

public class BottomBarButtonHover : MonoBehaviour, IPointerEnterHandler, IPointerExitHandler, IPointerDownHandler, IPointerUpHandler, IPointerMoveHandler
{
    public float hoverScale = 1.06f;
    public float pressScale = 0.92f;
    public float hoverWidthScale = 1.08f;
    public float scaleLerp = 12f;
    public float gyroAngle = 6f;
    public float gyroLerp = 12f;

    private RectTransform rect;
    private LayoutElement layout;
    private float basePreferredWidth;
    private Vector3 baseScale;
    private bool hovering;
    private bool pressed;
    private Vector3 targetScale;
    private Quaternion targetRotation = Quaternion.identity;
    private Camera eventCamera;
    private RectTransform layoutRoot;

    private void Awake()
    {
        rect = GetComponent<RectTransform>();
        baseScale = transform.localScale;
        targetScale = baseScale;

        layout = GetComponent<LayoutElement>();
        if (layout == null)
            layout = gameObject.AddComponent<LayoutElement>();

        basePreferredWidth = layout.preferredWidth;
        if (basePreferredWidth <= 0f && rect != null)
            basePreferredWidth = rect.rect.width;

        if (basePreferredWidth <= 0f)
            basePreferredWidth = 100f;

        layout.preferredWidth = basePreferredWidth;

        var group = GetComponentInParent<LayoutGroup>();
        if (group != null)
            layoutRoot = group.GetComponent<RectTransform>();
    }

    private void Update()
    {
        float dt = Time.unscaledDeltaTime;
        transform.localScale = Vector3.Lerp(transform.localScale, targetScale, 1f - Mathf.Exp(-scaleLerp * dt));

        if (hovering)
        {
            Vector2 localPoint;
            if (rect != null && RectTransformUtility.ScreenPointToLocalPointInRectangle(rect, Input.mousePosition, eventCamera, out localPoint))
            {
                Vector2 size = rect.rect.size;
                float nx = size.x > 0f ? localPoint.x / size.x : 0f;
                float ny = size.y > 0f ? localPoint.y / size.y : 0f;
                float rotX = -ny * gyroAngle * 2f;
                float rotY = nx * gyroAngle * 2f;
                targetRotation = Quaternion.Euler(rotX, rotY, 0f);
            }
        }
        else
        {
            targetRotation = Quaternion.identity;
        }

        transform.localRotation = Quaternion.Slerp(transform.localRotation, targetRotation, 1f - Mathf.Exp(-gyroLerp * dt));
    }

    public void OnPointerEnter(PointerEventData eventData)
    {
        hovering = true;
        eventCamera = eventData.pressEventCamera;
        layout.preferredWidth = basePreferredWidth * hoverWidthScale;
        RebuildLayout();
        if (!pressed)
            targetScale = baseScale * hoverScale;
    }

    public void OnPointerExit(PointerEventData eventData)
    {
        hovering = false;
        layout.preferredWidth = basePreferredWidth;
        RebuildLayout();
        if (!pressed)
            targetScale = baseScale;
    }

    public void OnPointerDown(PointerEventData eventData)
    {
        pressed = true;
        targetScale = baseScale * pressScale;
    }

    public void OnPointerUp(PointerEventData eventData)
    {
        pressed = false;
        targetScale = baseScale * (hovering ? hoverScale : 1f);
    }

    public void OnPointerMove(PointerEventData eventData)
    {
        eventCamera = eventData.pressEventCamera;
    }

    private void RebuildLayout()
    {
        if (layoutRoot != null)
            LayoutRebuilder.ForceRebuildLayoutImmediate(layoutRoot);
    }
}