using System.Collections;

using System.Collections.Generic;

using UnityEngine;

using GameBase.Extensions;

using GameBase.Patterns;

using System;

using System.Linq;

using UnityEngine.Events;

​

[RequireComponent( typeof( Grid ) )]

[ExecuteInEditMode]

public class GridViewManager : Singleton<GridViewManager>

{

  public Transform Root;

​

  public Grid UnityGrid;

  public Vector2Int GridViewPortSize;

  public List<Node> NodesInView = new List<Node>();

  public Vector3Int? CurrentCenter;

  public bool DrawGizmos;

  public bool ToggleDebugLogs;

  public int GridSize { get; private set; }

  public int test;

  public Action<Node> OnNodeAdded;

  public Action<Node> OnNodeRemoved;

​

​

  void OnEnable()

  {

    GridSize = GridViewPortSize.x * GridViewPortSize.y;

    NodesInView = new List<Node>( GridSize );

  }

​

  void Update()

  {

    Vector3Int center = GetCenter();

    if ( CurrentCenter != center )

    {

      CurrentCenter = center;

      CalculateAndMessageNodes();

    }

  }

​

  private void CalculateAndMessageNodes()

  {

    List<Node> potentialNodes = new List<Node>( GridSize );

    for ( int x = 0 ; x < GridViewPortSize.x ; x++ )

    {

      for ( int y = 0 ; y < GridViewPortSize.y ; y++ )

      {

        //Generate a node based off this camera pos

        var gridPos = new Vector3Int(

          CurrentCenter.Value.x - ( GridViewPortSize.x / 2 ) + x,

          CurrentCenter.Value.y - ( GridViewPortSize.y / 2 ) + y,

          0 );

​

        Node node = new Node( gridPos );

​

        //Add it to our potentially new nodes list

        potentialNodes.Add( node );

​

        //Take items only from the first list, that are not present in the second

        List<Node> newNodes = potentialNodes.Except( NodesInView ).ToList();

        if ( newNodes == null || newNodes.Count == 0 )

        {

          continue; //No new nodes added in this update (so far)

        }

​

        //newNodes has more stuff? Add, then message

        NodesInView.Add( node );

        OnNodeAdded?.Invoke( node );

​

        if ( ToggleDebugLogs )

          Debug.Log( "Spawning node at: <b>" + ( Vector2 )node.Center + "</b>" );

      }

    }

​

    //Clean the nodes in view by removing NodesInView based off of the new list

    List<Node> oldNodes = NodesInView.Except( potentialNodes ).ToList();

    for ( int i = 0 ; i < oldNodes.Count ; i++ )

    {

      NodesInView.Remove( oldNodes[ i ] );

      OnNodeRemoved?.Invoke( oldNodes[ i ] );

​

      if ( ToggleDebugLogs )

        Debug.Log( "Removing node at: <b>" + ( Vector2 )oldNodes[ i ].Center + "</b>" );

    }

  }

​

  private void OnDrawGizmos()

  {

    if ( DrawGizmos )

    {

      if ( NodesInView != null )

      {

        for ( int i = 0 ; i < NodesInView.Count ; i++ )

        {

          Gizmos.DrawWireCube( NodesInView[ i ].Center, new Vector3( 0.8f, 0.8f, 0.8f ) );

        }

      }

    }

  }

​

  private Vector3Int GetCenter()

  {

    return UnityGrid.LocalToCell( Root.position );

  }

​

  private void OnDisable()

  {

    NodesInView.Clear();

  }

​

  private void OnValidate()

  {

    if ( Root == null )

    {

      Debug.LogError( "A Root must be set!" );

    }

  }

}

​