using System.Collections.Generic;
using Gameplay.Level;
namespace Gameplay.Area.Around
{
    public static class AroundHelper
    {
        
        private static List<int> _cacheWorkList = new List<int>();
        private static List<int> _cacheNextWorkList = new List<int>();
        private static List<int> _cacheVisitList = new List<int>();
        private static List<TGS.Cell> _cacheCellList = new List<TGS.Cell>();

        public static void GetAround(int centerIndex, int stepCount, List<int> result)
        {
            var workStep = 0;
            _cacheWorkList.Clear();
            _cacheVisitList.Clear();
            _cacheCellList.Clear();
            
            _cacheWorkList.Add(centerIndex);
            _cacheVisitList.Add(centerIndex);
            var mapTgs = LevelManager.Instance.CurrentLevel.Map.TerrainGridSystem;
            
            while (true)
            {
                _cacheNextWorkList.Clear();
                for (var i = 0; i < _cacheWorkList.Count; ++i)
                {
                    var index = _cacheWorkList[i];
                    mapTgs.CellGetNeighbours(index, _cacheCellList);
                    for (int j = 0; j < _cacheCellList.Count; j++)
                    {
                        var cell = _cacheCellList[j];
                        if (_cacheVisitList.Contains(cell.index))
                        {
                            continue;
                        }
                        result.Add(cell.index);
                        _cacheNextWorkList.Add(cell.index);
                        _cacheVisitList.Add(cell.index);
                    }
                }
                
                workStep++;
                if (workStep >= stepCount)
                {
                    break;
                }
                
                _cacheWorkList.Clear();
                _cacheWorkList.AddRange(_cacheNextWorkList);
            }
            
        }
        
    }
}