class RQRCode::Export::SVG::Path

def build(module_size, options = {})
  # Extract values from options
  color = options[:color]
  offset_x = options[:offset_x].to_i
  offset_y = options[:offset_y].to_i
  # Prefix hexadecimal colors unless using a named color (symbol)
  color = "##{color}" unless color.is_a?(Symbol)
  modules_array = @qrcode.modules
  matrix_width = matrix_height = modules_array.length + 1
  empty_row = [Array.new(matrix_width - 1, false)]
  edge_matrix = Array.new(matrix_height) { Array.new(matrix_width) }
  (empty_row + modules_array + empty_row).each_cons(2).with_index do |row_pair, row_index|
    first_row, second_row = row_pair
    # horizontal edges
    first_row.zip(second_row).each_with_index do |cell_pair, column_index|
      edge = case cell_pair
      when [true, false] then Edge.new column_index + 1, row_index, :left
      when [false, true] then Edge.new column_index, row_index, :right
      end
      (edge_matrix[edge.start_y][edge.start_x] ||= []) << edge if edge
    end
    # vertical edges
    ([false] + second_row + [false]).each_cons(2).each_with_index do |cell_pair, column_index|
      edge = case cell_pair
      when [true, false] then Edge.new column_index, row_index, :down
      when [false, true] then Edge.new column_index, row_index + 1, :up
      end
      (edge_matrix[edge.start_y][edge.start_x] ||= []) << edge if edge
    end
  end
  edge_count = edge_matrix.flatten.compact.count
  path = []
  while edge_count > 0
    edge_loop = []
    next_matrix_cell = edge_matrix.find(&:any?).find { |cell| cell&.any? }
    edge = next_matrix_cell.first
    while edge
      edge_loop << edge
      matrix_cell = edge_matrix[edge.start_y][edge.start_x]
      matrix_cell.delete edge
      edge_matrix[edge.start_y][edge.start_x] = nil if matrix_cell.empty?
      edge_count -= 1
      # try to find an edge continuing the current edge
      edge = edge_matrix[edge.end_y][edge.end_x]&.first
    end
    first_edge = edge_loop.first
    edge_loop_string = SVG_PATH_COMMANDS[:move]
    edge_loop_string += "#{first_edge.start_x} #{first_edge.start_y}"
    edge_loop.chunk(&:direction).to_a[0...-1].each do |direction, edges|
      edge_loop_string << "#{SVG_PATH_COMMANDS[direction]}#{edges.length}"
    end
    edge_loop_string << SVG_PATH_COMMANDS[:close]
    path << edge_loop_string
  end
  @result << %{<path d="#{path.join}" fill="#{color}" transform="translate(#{offset_x},#{offset_y}) scale(#{module_size})"/>}
end