# Nathan Hinton
# Holds a grid of each otem in the game

class GameGrid
  def initialize(game_width, game_height)

    @game_grid = []
    game_width.times do |xx|
      @game_grid.append(Array.new(game_height))
    end
  end


  ## Add an item to the grid
  # @param x [Integer] The x position (top left corner of item)
  # @param y [Integer] The y position (top left corner of item)
  # @param item [Object] The item to add. Should be an actual reference to the item
  # @retval [Boolean] True if the item was placed, false otherwise (space conflict)
  def add_item(x, y, item)
    size_x = item.size_x
    size_y = item.size_y

    puts "#{item.to_s}"
    puts "top left: (#{x}, #{y}), size: (#{size_x}, #{size_y})"

    # Check that the grid is empty in those spots:
    size_x.times do |xx|
      size_y.times do |yy|
        unless @game_grid[x + xx][y + yy].nil?
          puts "Failed to add item: #{item.to_s}:"
          puts " - top left: (#{x}, #{y}), size: (#{size_x}, #{size_y}), collision: (#{xx}, #{yy})"
          return false
        end
      end
    end

    # place item in grid
    size_x.times do |xx|
      size_y.times do |yy|
        @game_grid[x + xx][y + yy] = item
      end
    end
    return true
  end

  ## Add an item to the grid
  # @param x [Integer] The x position (top left corner of item)
  # @param y [Integer] The y position (top left corner of item)
  # @param item [Object] The item to remove. Used to ensure we are removing the right thing.
  def remove_item(x, y, item)
    size_x = item.size_x
    size_y = item.size_y

    # Check that the grid is empty in those spots:
    size_x.times do |xx|
      size_y.times do |yy|
        if @game_grid[x + xx][y + yy] != item
          raise RuntimeError.new('Item mismatch in internal game grid! Game state corrupted1')
        end
      end
    end

    # place item in grid
    size_x.times do |xx|
      size_y.times do |yy|
        @game_grid[x + xx][y + yy] = nil
      end
    end 
 end

end