using UnityEngine;
using TMPro;
using UnityEngine.EventSystems;
using System.Collections;

public class CustomTMPInputField : TMP_InputField
{
    private bool forceFocus = false;

    protected override void Awake()
    {
        base.Awake();
    }

    public override void OnPointerClick(PointerEventData eventData)
    {
        base.OnPointerClick(eventData);
        if (!forceFocus)
        {
            Activate();
        }
    }

    public override void OnDeselect(BaseEventData eventData)
    {
        if (forceFocus)
        {
            StartCoroutine(DelayedSelect());
        }
        else
        {
            base.OnDeselect(eventData);
        }
    }

    private IEnumerator DelayedSelect()
    {
        yield return null;

        if (EventSystem.current != null && EventSystem.current.currentSelectedGameObject != gameObject)
        {
            EventSystem.current.SetSelectedGameObject(gameObject);

            // TMP 原生激活输入框，显示光标
            ActivateInputField();

            // 强制同步 placeholder 状态
            ForceRefresh();
        }
    }

    /// <summary>
    /// 激活并保持焦点
    /// </summary>
    public void Activate()
    {
        forceFocus = true;
        StartCoroutine(DelayedSelect());
    }

    /// <summary>
    /// 主动关闭焦点
    /// </summary>
    public void Deactivate()
    {
        forceFocus = false;
        DeactivateInputField();

        if (EventSystem.current != null && EventSystem.current.currentSelectedGameObject == gameObject)
            EventSystem.current.SetSelectedGameObject(null);

        ForceRefresh();
    }

    /// <summary>
    /// 是否有焦点
    /// </summary>
    public bool HasFocus()
    {
        return forceFocus && isFocused;
    }

    /// <summary>
    /// 手动切换到另一个输入框
    /// </summary>
    public void SwitchFocus(CustomTMPInputField nextField)
    {
        if (nextField == null) return;

        ForceRefresh();
        Deactivate();

        nextField.Activate();
        nextField.ForceRefresh();
    }

    /// <summary>
    /// 强制刷新 placeholder 状态
    /// </summary>
    public void ForceRefresh()
    {
        if (placeholder != null)
            placeholder.gameObject.SetActive(string.IsNullOrEmpty(text) && !isFocused);
    }
}