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

public class esPrefab : MonoBehaviour, IPointerEnterHandler, IPointerExitHandler
{
    public Image esIcon;
    public Text esName;

    private int skillGroupId;
    private GameObject descriptionPrefab;
    private RectTransform descriptionRoot;
    private GameObject spawnedDescription;
    private RectTransform rectTransform;
    private Canvas rootCanvas;
    private Camera uiCamera;
    private Vector2 descriptionOffset = new Vector2(20f, 30f);

    private void Awake()
    {
        rectTransform = transform as RectTransform;
        rootCanvas = GetComponentInParent<Canvas>();
        if (rootCanvas != null && rootCanvas.renderMode != RenderMode.ScreenSpaceOverlay)
        {
            uiCamera = rootCanvas.worldCamera;
        }
    }

    private void OnDisable()
    {
        DestroyDescription();
    }

    private void OnDestroy()
    {
        DestroyDescription();
    }

    public void BindSkillGroup(int groupId, string displayName, Sprite icon, GameObject desPrefab, RectTransform ownerRoot, Vector2 offset)
    {
        skillGroupId = Mathf.Max(0, groupId);
        descriptionPrefab = desPrefab;
        descriptionRoot = ownerRoot;
        descriptionOffset = offset;

        if (esName != null)
        {
            esName.text = displayName ?? string.Empty;
        }

        if (esIcon != null)
        {
            esIcon.sprite = icon;
            esIcon.enabled = icon != null;
        }
    }

    public void OnPointerEnter(PointerEventData eventData)
    {
        ShowDescription();
    }

    public void OnPointerExit(PointerEventData eventData)
    {
        DestroyDescription();
    }

    private void ShowDescription()
    {
        if (spawnedDescription != null || descriptionPrefab == null || descriptionRoot == null || skillGroupId <= 0)
        {
            return;
        }

        SkillGroup skillGroup = EquipmentSkillGroupLibrary.ResolveSkillGroup(skillGroupId);
        if (skillGroup == null)
        {
            return;
        }

        spawnedDescription = Instantiate(descriptionPrefab, descriptionRoot);
        spawnedDescription.SetActive(true);
        spawnedDescription.transform.SetAsLastSibling();

        esDesPrefab description = spawnedDescription.GetComponent<esDesPrefab>();
        if (description != null)
        {
            description.Bind(skillGroup.groupName, skillGroup.groupIcon, skillGroup.skillDescriptionsText);
        }

        PositionDescription(spawnedDescription.transform as RectTransform);
    }

    private void PositionDescription(RectTransform descriptionRect)
    {
        if (descriptionRect == null || rectTransform == null || descriptionRoot == null)
        {
            return;
        }

        Vector3[] corners = new Vector3[4];
        rectTransform.GetWorldCorners(corners);
        Vector3 rightCenterWorld = (corners[2] + corners[3]) * 0.5f;
        Vector2 screenPoint = RectTransformUtility.WorldToScreenPoint(uiCamera, rightCenterWorld);
        if (!RectTransformUtility.ScreenPointToLocalPointInRectangle(descriptionRoot, screenPoint, uiCamera, out Vector2 localPoint))
        {
            return;
        }

        descriptionRect.anchorMin = new Vector2(0f, 1f);
        descriptionRect.anchorMax = new Vector2(0f, 1f);
        descriptionRect.pivot = new Vector2(0f, 1f);
        descriptionRect.anchoredPosition = localPoint + descriptionOffset;
    }

    private void DestroyDescription()
    {
        if (spawnedDescription == null)
        {
            return;
        }

        if (Application.isPlaying)
        {
            Destroy(spawnedDescription);
        }
        else
        {
            DestroyImmediate(spawnedDescription);
        }

        spawnedDescription = null;
    }
}