using System;
using System.Collections.Generic;
using AwesomeTechnologies.Utility;
using Unity.Collections;
using UnityEngine;

namespace AwesomeTechnologies.VegetationSystem
{
    [Serializable]
    public class PredictiveCellLoader
    {
        private readonly VegetationSystemPro _vegetationSystemPro;
        public readonly List<VegetationCell> PreloadVegetationCellList = new List<VegetationCell>();
        private readonly List<VegetationCell> _tempPreloadList = new List<VegetationCell>();
        public PredictiveCellLoader(VegetationSystemPro vegetationSystemPro)
        {
            _vegetationSystemPro = vegetationSystemPro;
        }

        public void Clear()
        {
            PreloadVegetationCellList.Clear();
        }
        
        public void ClearNonImportant()
        {
            for (int i = PreloadVegetationCellList.Count - 1; i >= 0; i--)
            {
                if (!PreloadVegetationCellList[i].Important)
                {
                    PreloadVegetationCellList.RemoveAtSwapBack(i);
                }                   
            }
        }
        
        public void RemoveCellsFlaggedForRemoval()
        {
            for (int i = PreloadVegetationCellList.Count - 1; i >= 0; i--)
            {
                if (PreloadVegetationCellList[i].FlagForRemoval)
                {
                    PreloadVegetationCellList.RemoveAtSwapBack(i);
                }                   
            }
        }

        
        public void GetCellsToLoad(List<VegetationCell> preloadList)
        {
            if (PreloadVegetationCellList.Count == 0) return;
            
            for (int i = 0; i <= _vegetationSystemPro.PredictiveCellLoaderCellsPerFrame - 1; i++)
            {
                VegetationCell vegetationCell = GetFirstUnloadedCell();
                if (vegetationCell != null)
                {
                    preloadList.Add(vegetationCell);
                }
            }
        }
        
        VegetationCell GetFirstUnloadedCell()
        {
            while (PreloadVegetationCellList.Count > 0)
            {
                VegetationCell vegetationCell = PreloadVegetationCellList[PreloadVegetationCellList.Count -1];
                PreloadVegetationCellList.RemoveAtSwapBack(PreloadVegetationCellList.Count - 1);
                if (vegetationCell.LoadedDistanceBand > 0)
                {
                    return vegetationCell;
                }
            }                      
            return null;
        }
        
        public void PreloadArea(Rect rect, bool important)
        {
            _tempPreloadList.Clear();
            _vegetationSystemPro.VegetationCellQuadTree.Query(rect,_tempPreloadList);
            for (int i = 0; i <= _tempPreloadList.Count - 1; i++)
            {
                VegetationCell vegetationCell = _tempPreloadList[i];
                if (vegetationCell.LoadedDistanceBand > 0)
                {
                    if (important)
                    {
                        vegetationCell.Important = true;
                    }
                    PreloadVegetationCellList.Add(vegetationCell);
                }
            }
        }

        public void PreloadArea(Rect rect, List<VegetationCell> overlapVegetationCellList, bool important)
        {
            _vegetationSystemPro.VegetationCellQuadTree.Query(rect,overlapVegetationCellList);
            for (int i = 0; i <= overlapVegetationCellList.Count - 1; i++)
            {
                VegetationCell vegetationCell = overlapVegetationCellList[i];
                if (vegetationCell.LoadedDistanceBand > 0)
                {
                    if (important)
                    {
                        vegetationCell.Important = true;
                    }
                    PreloadVegetationCellList.Add(vegetationCell);
                }
            }
        }
        
        public void PreloadArea(List<VegetationCell> overlapVegetationCellList, bool important)
        {
            for (int i = 0; i <= overlapVegetationCellList.Count - 1; i++)
            {
                VegetationCell vegetationCell = overlapVegetationCellList[i];
                if (vegetationCell.LoadedDistanceBand > 0)
                {
                    if (important)
                    {
                        vegetationCell.Important = true;
                    }
                    PreloadVegetationCellList.Add(vegetationCell);
                }
            }
        }

        public void PreloadArea(Vector3 position, float radiusMeter, bool important)
        {
           Rect rect = new Rect(new Vector2(position.x - radiusMeter, position.z  - radiusMeter), new Vector2(radiusMeter*2,radiusMeter*2));
           PreloadArea(rect,important);
        }

        public void PreloadAllVegetationCells()
        {
            for (int i = 0; i <= _vegetationSystemPro.VegetationCellList.Count - 1; i++)
            {
                VegetationCell vegetationCell = _vegetationSystemPro.VegetationCellList[i];
                if (vegetationCell.LoadedDistanceBand > 0)
                {
                    PreloadVegetationCellList.Add(vegetationCell);
                }
            }
        }
    }
}