using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.EventSystems;
using UnityEngine.UI;

public class JoyStickHandler : MonoBehaviour, IPointerDownHandler, IDragHandler, IPointerUpHandler
{
    /// <summary>
    /// 摇杆水平偏移量
    /// </summary>
    public static float js_x;
    /// <summary>
    /// 摇杆垂直偏移量
    /// </summary>
    public static float js_y;

    // 当前模式    
    public static Mode CurrentMode;

    /// <summary>
    /// 摇杆模式
    /// </summary>
    public enum Mode { None, Up, Down, Left, Right };

    /// <summary>
    /// 背景图片RectTransform
    /// </summary>
    [Tooltip("背景图片RectTransform")]
    public RectTransform background;
    /// <summary>
    /// Handle的RectTransform
    /// </summary>
    [Tooltip("Handle的RectTransform")]
    public RectTransform handle;
    /// <summary>
    /// 摇杆速度偏移量
    /// </summary>
    [Tooltip("摇杆速度偏移量")]
    public float js_Speed = 1f;
    /// <summary>
    /// 画布
    /// </summary>
    [Tooltip("摇杆所在的画布对象")]
    private Canvas canvas;

    // 半径
    float radius;
    // 上下左右的向量
    Vector2 up, down, left, right;

    public bool TestOnEditor;

    Color handleColor;

    void Start()
    {
        if (!TestOnEditor && !H5Controller.IsMobileBroswer())
        {
            Destroy(gameObject);
        }
        canvas = transform.parent.parent.GetComponent<Canvas>();

        CurrentMode = Mode.None;
        radius = background.rect.width / 2.0f;
        up = new Vector2(0, radius);
        down = new Vector2(0, -radius);
        left = new Vector2(-radius, 0);
        right = new Vector2(radius, 0);

        handleColor = handle.GetComponent<Image>().color;
    }

    #region
    //void Update()
    //{
    //    // MessageSend();
    //}
    void MessageSend()
    {
        switch (CurrentMode)
        {
            case Mode.None:
                break;
            case Mode.Up:
                break;
            case Mode.Left:
                break;
            case Mode.Down:
                break;
            case Mode.Right:
                break;
        }
    }
    #endregion

    // 鼠标按下
    public void OnPointerDown(PointerEventData eventData)
    {
        if (BaseController.CanControl)
        {
            OnDrag(eventData);

            handle.GetComponent<Image>().color = new Color(150, 150, 150, 255);
        }
    }

    // 鼠标放开
    public void OnPointerUp(PointerEventData eventData)
    {
        if (BaseController.CanControl)
        {
            js_x = 0;
            js_y = 0;

            handle.anchoredPosition = Vector2.zero;
            handle.GetComponent<Image>().color = handleColor;
            CurrentMode = Mode.None;
        }
    }

    // 临时变量
    Vector2 to;
    public void OnDrag(PointerEventData eventData)
    {
        if (BaseController.CanControl)
        {
            to = (eventData.position - (Vector2)background.position) / canvas.scaleFactor;
            if (to.magnitude <= radius)
            {
                handle.anchoredPosition = to;
            }
            else
            {
                to = to / (to.magnitude / radius);
                handle.anchoredPosition = to;
            }

            CalcDis();
        }
    }
    void CalcDis()
    {
        float dis = 0f;
        if (Vector2.Distance(up, handle.anchoredPosition) < dis || dis == 0)
        {
            dis = Vector2.Distance(up, handle.anchoredPosition);
            CurrentMode = Mode.Up;
        }
        if (Vector2.Distance(down, handle.anchoredPosition) < dis)
        {
            dis = Vector2.Distance(down, handle.anchoredPosition);
            CurrentMode = Mode.Down;
        }
        if (Vector2.Distance(left, handle.anchoredPosition) < dis)
        {
            dis = Vector2.Distance(left, handle.anchoredPosition);
            CurrentMode = Mode.Left;
        }
        if (Vector2.Distance(right, handle.anchoredPosition) < dis)
        {
            dis = Vector2.Distance(right, handle.anchoredPosition);
            CurrentMode = Mode.Right;
        }

        js_x = (radius - Vector2.Distance(right, handle.anchoredPosition)) / radius * js_Speed;
        js_y = (radius - Vector2.Distance(up, handle.anchoredPosition)) / radius * js_Speed;
    }
}