using System.Collections.Generic;
using Gameplay.Level;
using UnityEngine;
namespace Gameplay.Area.BoardView
{
    public class BoardViewHelper
    {
        
        private static List<int> _cacheCellIndexList = new List<int>();
        
        public static List<BoardViewData> GenerateBoard(List<int> cellIndexList)
        {
            _cacheCellIndexList.Clear();
            _cacheCellIndexList.AddRange(cellIndexList);
            var result = new List<BoardViewData>();
            
            var tgsSystem = LevelManager.Instance.CurrentLevel.Map.TerrainGridSystem;
            BoardViewData workViewData = null;
            List<int> workCellIndexList = new List<int>();
            List<int> nextWorkCellIndexList = new List<int>();
            while (_cacheCellIndexList.Count > 0)
            {
                if (workViewData == null)
                {
                    workCellIndexList.Clear();
                    var workCellIndex = _cacheCellIndexList[^1];
                    _cacheCellIndexList.RemoveAt(_cacheCellIndexList.Count - 1);
                    workViewData = new BoardViewData();
                    workViewData.cellIndexList.Add(workCellIndex);
                    result.Add(workViewData);
                    workCellIndexList.Add(workCellIndex);
                }
                else
                {
                    nextWorkCellIndexList.Clear();
                    for (int j = 0; j < workCellIndexList.Count; j++)
                    {
                        var workCellIndex = workCellIndexList[j];
                        var aroundCell = tgsSystem.CellGetNeighbours(workCellIndex);
                        for (int i = 0; i < aroundCell.Count; i++)
                        {
                            var cell = aroundCell[i];
                            var findIndex = _cacheCellIndexList.IndexOf(cell.index);
                            if (findIndex == -1)
                            {
                                continue;
                            }
                            workViewData.cellIndexList.Add(cell.index);
                            // fast remove
                            _cacheCellIndexList[findIndex] = _cacheCellIndexList[^1];
                            _cacheCellIndexList.RemoveAt(_cacheCellIndexList.Count - 1);
                            nextWorkCellIndexList.Add(cell.index);
                        }
                    }
                    if (nextWorkCellIndexList.Count == 0)
                    {
                        workViewData = null;
                    }
                    else
                    {
                        // switch work list
                        workCellIndexList.Clear();
                        workCellIndexList.AddRange(nextWorkCellIndexList);
                    }
                }
            }
            
            return result;
        }
    }
}