Implementing Wilson's Algorithm

class Wilsons
  def self.on(grid)
    unvisited = [] 
    grid.each_cell { |cell| unvisited << cell }
    first = unvisited.sample 
    unvisited.delete(first) 
    while unvisited.any? 
      cell = unvisited.sample 
      path = [cell]
      while unvisited.include?(cell) 
        cell = cell.neighbors.sample 
        position = path.index(cell) 
        if position
          path = path[0..position] 
        else
          path << cell 
        end
      end 
      0.upto(path.length-2) do |index| 
        path[index].link(path[index + 1]) 
        unvisited.delete(path[index]) 
      end 
    end
    grid
  end
end