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

[CustomEditor(typeof(DrawShadowMask))]
public class DrawShadowMaskEditor : Editor
{
    DrawShadowMask inst;
    Ray ray;
    RaycastHit hit;
    float brushSize;
    Vector2 centerPosRecord;

    private void OnEnable()
    {
        inst = (DrawShadowMask)target;
    }

    public override void OnInspectorGUI()
    {
        base.OnInspectorGUI();

        //
        GUILayout.Space(100);
        GUILayout.BeginHorizontal();
        if (GUILayout.Button("Clear", GUILayout.Height(50)))
        {
            Clear();
        }
        if (GUILayout.Button("Fill", GUILayout.Height(50)))
        {
            Fill();
        }
        GUILayout.EndHorizontal();
    }

    void Clear()
    {
        for (int y = 0; y <= inst.shadowMaskTex.height; ++y)
        {
            for (int x = 0; x <= inst.shadowMaskTex.width; ++x)
            {
                inst.shadowMaskTex.SetPixel(x, y, Color.black);
            }
        }

        inst.shadowMaskTex.Apply();
    }

    void Fill()
    {
        for (int y = 0; y <= inst.shadowMaskTex.height; ++y)
        {
            for (int x = 0; x <= inst.shadowMaskTex.width; ++x)
            {
                inst.shadowMaskTex.SetPixel(x, y, Color.white);
            }
        }

        inst.shadowMaskTex.Apply();
    }



    private void OnSceneGUI()
    {
        if(!inst.shadowMaskTex && !inst.mat)
        {
            return;
        }

        if(Selection.activeObject == inst.gameObject)
        {
            HandleUtility.AddDefaultControl(GUIUtility.GetControlID(FocusType.Passive));

            //
            ray = HandleUtility.GUIPointToWorldRay(Event.current.mousePosition);
            if (Physics.Raycast(ray, out hit, 2000, 1 << LayerMask.NameToLayer("DrawHelp")))
            {
                if (Event.current.type == EventType.MouseDown && Event.current.button == 0)
                {
                    inst.isDrawing = true;
                }

                brushSize = inst.brushSize;

                if (inst.isDrawing)
                {
                    Handles.color = Color.green;

                    //
                    Vector2Int centerPos = new Vector2Int((int)(hit.textureCoord.x * inst.shadowMaskTex.width), (int)(hit.textureCoord.y * inst.shadowMaskTex.height));
                    if(centerPosRecord != centerPos)
                    {
                        centerPosRecord = centerPos;

                        //
                        Handles.color = Color.green;
                        Handles.Label(hit.point, centerPos.ToString());

                        for (int y = -(int)brushSize; y <= (int)brushSize; ++y)
                        {
                            for (int x = -(int)brushSize; x <= (int)brushSize; ++x)
                            {
                                Vector2Int rang = new Vector2Int(x, y) + centerPos;
                                if (rang.x > 0 && rang.x < inst.shadowMaskTex.width || rang.y > 0 && rang.y < inst.shadowMaskTex.height)
                                {
                                    Color col = inst.shadowMaskTex.GetPixel(rang.x, rang.y);
                                    float dis = 1 - 1 / Vector2.Distance(centerPos, rang);
                                    inst.shadowMaskTex.SetPixel(rang.x, rang.y, Color.Lerp(inst.color, col, dis * (1 - inst.color.a)));
                                }
                            }
                        }

                        inst.shadowMaskTex.Apply();
                    }
                }

                if (Event.current.type == EventType.MouseUp && Event.current.button == 0)
                {
                    inst.isDrawing = false;

                    Handles.color = Color.red;
                }

                Handles.DrawWireDisc(hit.point, Vector3.up, brushSize * 0.1f);
                SceneView.RepaintAll();
            }
        }
    }
}