using UnityEngine;
using UnityEngine.EventSystems;

public class UGUISlideBar : MonoBehaviour, IPointerDownHandler, IPointerUpHandler
{
    [SerializeField] private RectTransform FillRT;
    [SerializeField] private TMPro.TextMeshProUGUI PercentTMP;
    [SerializeField] private bool InitOnPointerUp = false;
    private RectTransform rt;
    private float MaxWidth;
    private Camera uiCamera;
    private bool checkable = false;

    public System.Action OnValueChanged;

    public bool Controlable { get; set; } = true;

    /// <summary>Normalized Value. 0 ~ 1 </summary>
    public float Value
    {
        get
        {
            float result = Mathf.Clamp(FillRT.sizeDelta.x / MaxWidth, 0f, 1f);
            return result;
        }
        set
        {
            FillRT.sizeDelta = new Vector2(Mathf.Clamp(value * MaxWidth, 0, MaxWidth), FillRT.sizeDelta.y);
            if (PercentTMP != null)
                PercentTMP.text = (FillRT.sizeDelta.x / MaxWidth * 100f).ToString("N1") + "%";
            OnValueChanged?.Invoke();
        }
    }

    private void Awake()
    {
        rt = this.GetComponent<RectTransform>();
        MaxWidth = rt.rect.width;

        uiCamera = this.transform.root.Find("PopupCanvas").GetComponent<Canvas>().worldCamera;
    }

    private void OnEnable()
    {
        Value = 0;
    }

    private void OnDisable()
    {
        checkable = false;
    }

    private void Update()
    {
        if (!checkable || !Controlable) return;

#if UNITY_EDITOR
        if (uiCamera != null && Input.GetMouseButton(0))
#elif UNITY_ANDROID
            if (uiCamera != null && Input.touchCount > 0)
#endif
        {
            Vector2 local;
#if UNITY_EDITOR
            if (RectTransformUtility.ScreenPointToLocalPointInRectangle(FillRT, Input.mousePosition, uiCamera, out local))
#elif UNITY_ANDROID
            if (RectTransformUtility.ScreenPointToLocalPointInRectangle(FillRT, Input.GetTouch(0).position, uiCamera, out local))
#endif
            {
                FillRT.sizeDelta = new Vector2(Mathf.Clamp(local.x, 0, MaxWidth), FillRT.sizeDelta.y);
                OnValueChanged?.Invoke();

                if (PercentTMP != null)
                    PercentTMP.text = (FillRT.sizeDelta.x / MaxWidth * 100f).ToString("N1") + "%";
            }
        }
    }

    public void OnPointerDown(PointerEventData eventData)
    {
        if (Controlable)
            checkable = true;
    }

    public void OnPointerUp(PointerEventData eventData)
    {
        if (Controlable)
            checkable = false;

        if (InitOnPointerUp)
            Value = 0f;
    }
}