using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;

// Scene视图中的自定义handles
public static class EditorHandlesHelper
{
    static int s_ValueScaleHandleHash;

    // limit value 数据
    static float s_StartScale;
    static float s_ValueDrag;
    static float s_ScaleDrawLength;

    // style 
    static GUIStyle s_StyleBlackLabel;
    static GUIStyle s_StyleWhiteLabel;
    static Dictionary<int/*color*/, GUIStyle> s_StyleLabels;

    static EditorHandlesHelper()
    {
        s_ValueScaleHandleHash = "ValueScaleHandleHash".GetHashCode();

        SetupStyles();
    }

    static void SetupStyles()
    {
        s_StyleBlackLabel = new GUIStyle();
        s_StyleBlackLabel.normal.textColor = Color.black;
        s_StyleWhiteLabel = new GUIStyle();
        s_StyleWhiteLabel.normal.textColor = Color.white;
        s_StyleLabels = new Dictionary<int, GUIStyle>();
    }

    #region 单一handle

    // 箭头
    public static void Arrow(Vector3 position, Vector3 direction, float length = 1f, float arrowSize = 0.1f, bool dotted = false)
    {
        direction = direction.normalized;
        if(!dotted)
            Handles.DrawLine(position, position + direction * length);
        else
            Handles.DrawDottedLine(position, position + direction * length,1f);
        Handles.ConeHandleCap(0, position + direction * length, Quaternion.LookRotation(direction, Vector3.up), arrowSize, EventType.Repaint);
    }

    // 控制数值的箭头
    public static float ScaleValue(float value, Vector3 position, Vector3 direction, float length, Handles.CapFunction capFunc, Quaternion capRot, float size, float snap = 0)
    {
        Handles.DrawLine(position, position + direction * length);
        value = ScaleValue(value, position + direction, capRot, size, capFunc, snap);
        return value;
    }

    // 控制数值的handle
    public static float ScaleValue(float value, Vector3 position, Quaternion rotation, float size, Handles.CapFunction capFunc, float snap)
    {
        int controlID = GUIUtility.GetControlID(s_ValueScaleHandleHash, FocusType.Keyboard);
        int id = controlID;
        Event current = Event.current;
        switch (current.GetTypeForControl(id))
        {
            case EventType.MouseDown:
                if ((HandleUtility.nearestControl == id && current.button == 0) || (GUIUtility.keyboardControl == id && current.button == 2))
                {
                    GUIUtility.keyboardControl = id;
                    GUIUtility.hotControl = id;
                    s_StartScale = value;
                    s_ValueDrag = 0f;
                    current.Use();
                    EditorGUIUtility.SetWantsMouseJumping(1);
                }
                break;
            case EventType.MouseUp:
                if (GUIUtility.hotControl == id && (current.button == 0 || current.button == 2))
                {
                    GUIUtility.hotControl = 0;
                    s_ScaleDrawLength = 1f;
                    current.Use();
                    EditorGUIUtility.SetWantsMouseJumping(0);
                }
                break;
            case EventType.MouseDrag:
                if (GUIUtility.hotControl == id)
                {
                    s_ValueDrag += HandleUtility.niceMouseDelta * 0.01f;
                    value = (Handles.SnapValue(s_ValueDrag, snap) + 1f) * s_StartScale;
                    s_ScaleDrawLength = value / s_StartScale;
                    GUI.changed = true;
                    current.Use();
                }
                break;
            case EventType.KeyDown:
                if (GUIUtility.hotControl == id && current.keyCode == KeyCode.Escape)
                {
                    value = s_StartScale;
                    s_ScaleDrawLength = 1f;
                    GUIUtility.hotControl = 0;
                    GUI.changed = true;
                    current.Use();
                }
                break;
            case EventType.Repaint:
                {
                    Color color = Color.white;
                    if (id == GUIUtility.keyboardControl)
                    {
                        color = Handles.color;
                        Handles.color = Handles.selectedColor;
                    }
                    capFunc(id, position, rotation, size * 0.15f, EventType.Repaint);
                    if (id == GUIUtility.keyboardControl)
                    {
                        Handles.color = color;
                    }
                    break;
                }
            case EventType.Layout:
                HandleUtility.AddControl(id, HandleUtility.DistanceToCircle(position, size * 0.15f));
                break;
        }
        return value;
    }

    // 带背景的label
    public static void Label(Vector3 position, string label, Color textColor)
    {
        GUIStyle textStyle = TryGetLabelStyleOrCreate(textColor);
        Handles.Label(position, label, textStyle);
    }

    public static void WireCube(Vector3 position, Vector3 size, Color col)
    {
        Color c = Handles.color;
        Handles.color = col;
        Handles.DrawWireCube(position, size);
        Handles.color = c;
    }

    #endregion

    #region 复合handle

    #endregion

    #region 内部方法

    static GUIStyle TryGetLabelStyleOrCreate(Color color)
    {
        GUIStyle style;
        if (!s_StyleLabels.TryGetValue(color.GetHashCode(), out style))
        {
            style = new GUIStyle();
            style.normal.textColor = color;
            s_StyleLabels.Add(color.GetHashCode(), style);
        }
        return style;
    }

    #endregion 

}