using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using Sirenix.OdinInspector;

public class MeshSelection : MonoBehaviour
{
    [DetailedInfoBox("使用说明", "1、选择要修改的物体\n2、点击开始选择，然后“ctrl+左键”选择网格上的面，选择完毕后点击生成\n3、选择第二个面进行生成点位\n4、点击生成中心点")]

    [LabelText("需要修改的物体")]
    public GameObject ToolSelectObj;

    [HideInInspector]
    public List<int> SelectedTrianglesIndex = new List<int>();
    [HideInInspector]
    public HashSet<Vector3> TrianglesVector3s = new HashSet<Vector3>();

    [LabelText("第一个点位")]
    [ShowIf("showF"), ReadOnly]
    public GameObject firstObj;

    [LabelText("第二个点位")]
    [ShowIf("showS"),ReadOnly]
    public GameObject SecondObj;

    bool showF = false;
    bool showS = false;
    bool showC = false;


    public void GetBoundaryVertices(Mesh mesh)
    {
        Vector3[] vertices = mesh.vertices;
        int[] triangles = mesh.triangles;

        Dictionary<(int, int), int> edgeFaces = new Dictionary<(int, int), int>();

        foreach (var i in SelectedTrianglesIndex)
        {
            int a = triangles[i];
            int b = triangles[i + 1];
            int c = triangles[i + 2];

            RegisterEdge(a, b, edgeFaces);
            RegisterEdge(b, c, edgeFaces);
            RegisterEdge(c, a, edgeFaces);

            
        }

        foreach (var edge in edgeFaces)
        {
            if (edge.Value == 1)
            {
                TrianglesVector3s.Add(ToolSelectObj.transform.TransformPoint(vertices[edge.Key.Item1]));
                TrianglesVector3s.Add(ToolSelectObj.transform.TransformPoint(vertices[edge.Key.Item2]));
            }
        }

    }
    private static void RegisterEdge(int a, int b, Dictionary<(int, int), int> edgeFaces)
    {
        var edge = a < b ? (a, b) : (b, a);
        edgeFaces.TryGetValue(edge, out int count);
        edgeFaces[edge] = count + 1;
    }

    public void CreateCenter()
    {
        Vector3 v3 = Vector3.zero;
        foreach(Vector3 vector3 in TrianglesVector3s)
        {
            v3 += vector3;
        }

        if(firstObj == null)
        {
            firstObj = new GameObject();
            firstObj.transform.SetParent(ToolSelectObj.transform.parent, true);
            firstObj.transform.position = v3 / TrianglesVector3s.Count;
            firstObj.name = ToolSelectObj.name + "-第一个生成点";
            showF = true;
            TrianglesVector3s.Clear();
            if (showF && showS) showC = true;
            return;
        }

        if (SecondObj == null)
        {
            SecondObj = new GameObject();
            SecondObj.transform.SetParent(ToolSelectObj.transform.parent, true);
            SecondObj.transform.position = v3 / TrianglesVector3s.Count;
            SecondObj.name = ToolSelectObj.name + "-第二个生成点";
            showS = true;
            TrianglesVector3s.Clear();
            if (showF && showS) showC = true;
            return;
        }


    }
    [Button("生成中心点")]
    [ShowIf("showC")]
    public void CreateCenterObj()
    {
        GameObject obj = new GameObject();
        obj.transform.SetParent(ToolSelectObj.transform.parent, true);
        obj.transform.position = (firstObj.transform.position + SecondObj.transform.position) / 2;
        obj.transform.rotation = Quaternion.LookRotation( (firstObj.transform.position - SecondObj.transform.position).normalized);
        obj.name = ToolSelectObj.name + "---生成点";
        ToolSelectObj.transform.SetParent(obj.transform);
        DestroyImmediate(firstObj);
        DestroyImmediate(SecondObj);
        showC= showF = showS = false;
        TrianglesVector3s.Clear();
    }

}