using System.Collections.Generic;
using Gameplay.Level;
using TGS;
using UnityEngine;
namespace Gameplay.Area.BoardView
{
    public class BoardViewHelper
    {
        
        private static List<Cell> _cacheCellIndexList = new List<Cell>();
        private static List<int> _cacheWorkCellIndexList = new List<int>();
        private static List<int> _cacheNextWorkCellIndexList = new List<int>();
        
        private static Cell _SearchFirstUnVisitedCell(List<Cell> cellIndexList)
        {
            for (int i = 0; i < cellIndexList.Count; i++)
            {
                var cell = cellIndexList[i];
                if (!cell.isVisited)
                {
                    return cell;
                }
            }
            return null;
        }
        
        public static void GenerateBoard(List<int> cellIndexList, List<BoardViewData> result, TerrainGridSystem tgs)
        {
            _cacheCellIndexList.Clear();
            var allCells = tgs.cells;
            var allCellCount = allCells.Count;
            for (int i = 0; i < allCellCount; i++)
            {
                var cell = allCells[i];
                cell.isVisited = true;
            }
            var cellCount = cellIndexList.Count;
            for (int i = 0; i < cellCount; i++)
            {
                var cellIndex = cellIndexList[i];
                var cell = tgs.cells[cellIndex];
                _cacheCellIndexList.Add(cell);
                cell.isVisited = false;
            }
            
            var tgsSystem = tgs;
            BoardViewData workViewData = null;
            
            _cacheWorkCellIndexList.Clear();
            _cacheNextWorkCellIndexList.Clear();
            var workCellIndexList = _cacheWorkCellIndexList;
            var nextWorkCellIndexList = _cacheNextWorkCellIndexList;
            while (true)
            {
                if (workViewData == null)
                {
                    var searchCell = _SearchFirstUnVisitedCell(_cacheCellIndexList);
                    if (searchCell == null)
                    {
                        break;
                    }
                    workCellIndexList.Clear();
                    searchCell.isVisited = true;
                    var searchCellIndex = searchCell.index;
                    workViewData = new BoardViewData();
                    workViewData.cellIndexList.Add(searchCellIndex);
                    result.Add(workViewData);
                    workCellIndexList.Add(searchCellIndex);
                }
                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];
                            if (cell.isVisited) continue;
                            workViewData.cellIndexList.Add(cell.index);
                            nextWorkCellIndexList.Add(cell.index);
                            cell.isVisited = true;
                        }
                    }
                    if (nextWorkCellIndexList.Count == 0)
                    {
                        workViewData = null;
                    }
                    else
                    {
                        // switch work list
                        workCellIndexList.Clear();
                        workCellIndexList.AddRange(nextWorkCellIndexList);
                    }
                }
            }
        }
    }
}