/// <summary>
/// Count how many neighbours of the specific cell are alive.
/// There are total 8 neighbours for a specific cell
/// </summary>
/// <param name="cell"> Cell for which neighbours needs to be find </param>
/// <param name="grid"> Grid which contains all cell information </param>
/// <returns> Retruns the info of all neighbours </returns>
public IEnumerable<ICell> RetrieveNeighbours(ICell cell, IGrid grid)
{
if (cell == null || grid == null) return null;
var neighbours = new List<ICell>();
var currCellPosition = cell.Position;
//CalculateDiagonalTopLeftNeighbour
currCellPosition.Row = cell.Position.Row - 1;
currCellPosition.Column = cell.Position.Column - 1;
if (IsValidIndex(currCellPosition, grid)) neighbours.Add(grid.GetCurrentCellInfo(currCellPosition));
//CalculateTopNeighbour
currCellPosition.Row = cell.Position.Row - 1;
currCellPosition.Column = cell.Position.Column;
if (IsValidIndex(currCellPosition, grid)) neighbours.Add(grid.GetCurrentCellInfo(currCellPosition));
//CalculateDiagonalTopRightNeighbour
currCellPosition.Row = cell.Position.Row - 1;
currCellPosition.Column = cell.Position.Column + 1;
if (IsValidIndex(currCellPosition, grid)) neighbours.Add(grid.GetCurrentCellInfo(currCellPosition));
//CalculateLeftNeighbour
currCellPosition.Row = cell.Position.Row;
currCellPosition.Column = cell.Position.Column - 1;
if (IsValidIndex(currCellPosition, grid)) neighbours.Add(grid.GetCurrentCellInfo(currCellPosition));
//CalculateRightNeighbour
currCellPosition.Row = cell.Position.Row;
currCellPosition.Column = cell.Position.Column + 1;
if (IsValidIndex(currCellPosition, grid)) neighbours.Add(grid.GetCurrentCellInfo(currCellPosition));
//CalculateDiagonalBottomLeftNeighbour
currCellPosition.Row = cell.Position.Row + 1;
currCellPosition.Column = cell.Position.Column - 1;
if (IsValidIndex(currCellPosition, grid)) neighbours.Add(grid.GetCurrentCellInfo(currCellPosition));
//CalculateBottomNeighbour
currCellPosition.Row = cell.Position.Row + 1;
currCellPosition.Column = cell.Position.Column;
if (IsValidIndex(currCellPosition, grid)) neighbours.Add(grid.GetCurrentCellInfo(currCellPosition));
//CalculateDiagonalBottomRightNeighbour
currCellPosition.Row = cell.Position.Row + 1;
currCellPosition.Column = cell.Position.Column + 1;
if (IsValidIndex(currCellPosition, grid)) neighbours.Add(grid.GetCurrentCellInfo(currCellPosition));
return neighbours;
}
