using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using UnityEngine;

namespace BITKit.Physics
{
    public class GetClosePointFromCollider : IClosePointProvider
    {
        public string Name="Default";
        public Transform Transform;
        public Vector3 Offset = default;
        public LayerMask LayerMask=LayerMask.NameToLayer("Default");
        public float Distance=1.6f;
        public float MinHeight=0.32f;
        public float MaxHeight = 1f;

        private readonly Collider[] _colliders=new Collider[8];
        private readonly Collider[] _mainCollider=new Collider[8];

        public GetClosePointFromCollider(Transform transform)
        {
            Transform = transform;
        }

        public bool TryGetValue(out Vector3 position, out Collider collider)
        {
            Vector3 vector3 = default;
            StringBuilder reportBuilder = new();
            reportBuilder.AppendLine($"检测任务:{Name}");
            position = Transform.position + Transform.rotation * Offset;
            var detectedLength = UnityEngine.Physics.OverlapSphereNonAlloc(position, Distance, _mainCollider, LayerMask);
            reportBuilder.AppendLine($"检测到了{detectedLength}个碰撞体");

            foreach (var collider1 in _mainCollider.Take(detectedLength).OrderBy(ByTop).Reverse())
                //for (var i = 0; i <detectedLength ; i++)
            {
                //reportBuilder.AppendLine($"----------------------------检测到了碰撞体{_mainCollider[i].name}");
                //var collider =  _mainCollider[i];
                if (collider1.isTrigger)
                {
                    reportBuilder?.AppendLine("碰撞体是触发器");
                    continue;
                }

                switch (collider1)
                {
                    case MeshCollider meshCollider:
                        if (meshCollider.convex is false)
                        {
                            reportBuilder?.AppendLine("MeshCollider未勾选Convex");
                            continue;
                        }

                        break;
                }

                var bounds = collider1.bounds;
                vector3 = collider1.ClosestPoint(Transform.position + Vector3.up * 64);
                var top = bounds.center.y + bounds.extents.y;
                Debug.DrawLine(Transform.position, Transform.position + Vector3.up * top, Color.blue, 8f);
                if (Transform.position.y + MinHeight > top)
                {
                    reportBuilder?.AppendLine("高度不足");
                    continue;
                }

                var nextPos = position;
                nextPos.y = collider1.bounds.center.y;

                {
                    var ray = new Ray(nextPos, Transform.forward);
                    if (collider1.Raycast(new Ray(nextPos, Transform.forward), out _, Distance) is false)
                    {
                        reportBuilder?.AppendLine("未检测到前方");
                        Debug.DrawRay(ray.origin,ray.direction,Color.red,Distance);
                        continue;
                    }
                }
              

                var height = Mathf.Abs(top - Transform.position.y);
                if (height > MaxHeight)
                {
                    reportBuilder?.AppendLine($"高度差距过大:{height}");
                    continue;
                }

                if (UnityEngine.Physics.Linecast(Transform.position, vector3, out var raycastHit2, LayerMask))
                {
                    if (raycastHit2.collider != collider1)
                    {
                        reportBuilder?.AppendLine($"检测到了其他碰撞体:{raycastHit2.transform.name}");
                        continue;
                    }
                }
                var length = UnityEngine.Physics.OverlapSphereNonAlloc(vector3, 0.01f, _colliders, LayerMask);
                switch (length)
                {
                    case 1:
                        if (_colliders[0] != collider1)
                        {
                            reportBuilder.AppendLine($"检测到了其他碰撞体{_colliders[0].name}");
                            continue;
                        }

                        break;
                    case > 1:
                        reportBuilder.AppendLine("检测到了更多碰撞体");
                        for (var ii = 0; ii < length; ii++)
                        {
                            //Debug.DrawLine(vector3, _colliders[ii].ClosestPoint(vector3), Color.red, 8);
                            reportBuilder.AppendLine($"\t{_colliders[ii].name}");
                        }

                        continue;
                }

                vector3.y = top;
                position = vector3;

                collider = collider1;

                reportBuilder.AppendLine("<color=green>成功</color>");
                //BIT4Log.Log<GetClosePointFromCollider>(reportBuilder.ToString());
                return true;
            }

            collider = null;
            //BIT4Log.Log<GetClosePointFromCollider>(reportBuilder.ToString());
            return false;
        }
        private float ByTop(Collider arg)
        {
            return arg.bounds.center.y + arg.bounds.extents.y;
        }
    }
}