using mh;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

/// <summary>
/// 基于图形的四叉树
/// </summary>
class PhysicsQuadtree
{
    /// <summary>
    /// 边界
    /// </summary>
    public Vector4 quadtreeRange { set { m_QuadtreeRange = value; } }
    private Vector4 m_QuadtreeRange;

    /// <summary>
    /// 根节点
    /// </summary>
    private Quadtree m_Quadtree;

    /// <summary>
    /// 托管的全部对象，但不一定会加入到树里面（中心点在边界外的不加入树）
    /// </summary>
    private List<IQuadTreeObject> m_Objects = new List<IQuadTreeObject>();

    public PhysicsQuadtree(Vector4 range)
    {
        m_QuadtreeRange = range;
        m_Quadtree = new Quadtree(0, range, true);
    }

    public void AddObject(IQuadTreeObject obj)
    {
        m_Objects.Add(obj);
    }

    public void RemoveObject(IQuadTreeObject obj)
    {
        m_Objects.Remove(obj);
    }

    /// <summary>
    /// 重建四叉树
    /// </summary>
    public void UpdateQuadtree()
    {
        m_Quadtree.Clear(false);
        m_Quadtree.Rebound(m_QuadtreeRange);
        InsertAllObjects();
    }

    private void InsertAllObjects()
    {
        Vector4 bound = m_Quadtree.bound;
        for (int i = 0; i < m_Objects.Count; i++)
        {
            IQuadTreeObject obj = m_Objects[i];
            // 简单的忽略中心在边界外的object
            if (PhysicsManager.IsPointInsideBox(bound, obj.bound.xy()))
            {
                m_Quadtree.Insert(obj);
            }
        }
    }

    public void Debug()
    {
        Color c = Gizmos.color;
        Gizmos.color = Color.green;
        m_Quadtree?.Iterate((t) =>
        {
            Vector3 pos = new Vector3(t.x, t.y, 0);
            Vector3 size = new Vector3(t.w, t.h, 1);
            Gizmos.DrawWireCube(pos, size);
        });
        Gizmos.color = c;
    }

    public bool Retrive(ref List<IQuadTreeObject> returnObjs, IQuadTreeObject obj)
    {
        return m_Quadtree.Retrieve(ref returnObjs, obj);
    }

    public bool Retrive(ref List<IQuadTreeObject> returnObjs, Vector4 bound)
    {
        return m_Quadtree.Retrieve(ref returnObjs, bound);
    }

}