class Pry
  class Code

    # Represents a line of code. A line of code is a tuple, which consists of a
    # line and a line number. A `LOC` object's state (namely, the line
    # parameter) can be changed via instance methods. `Pry::Code` heavily uses
    # this class.
    #
    # @api private
    # @example
    #   loc = LOC.new("def example\n  :example\nend", 1)
    #   puts loc.line
    #   def example
    #     :example
    #   end
    #   #=> nil
    #
    #   loc.indent(3)
    #   loc.line #=> "   def example\n  :example\nend"
    class LOC

      # @return [Array<String, Integer>]
      attr_reader :tuple

      # @param [String] line The line of code.
      # @param [Integer] lineno The position of the +line+.
      def initialize(line, lineno)
        @tuple = [line.chomp, lineno.to_i]
      end

      # @return [Boolean]
      def ==(other)
        other.tuple == tuple
      end

      def dup
        self.class.new(line, lineno)
      end

      # @return [String]
      def line
        tuple.first
      end

      # @return [Integer]
      def lineno
        tuple.last
      end

      # Paints the `line` of code.
      #
      # @param [Symbol] code_type
      # @return [void]
      def colorize(code_type)
        tuple[0] = CodeRay.scan(line, code_type).term
      end

      # Prepends the line number `lineno` to the `line`.
      #
      # @param [Integer] max_width
      # @return [void]
      def add_line_number(max_width = 0)
        padded = lineno.to_s.rjust(max_width)
        colorized_lineno = Pry::Helpers::BaseHelpers.colorize_code(padded)
        tuple[0] = "#{ colorized_lineno }: #{ line }"
      end

      # Prepends a marker "=>" or an empty marker to the +line+.
      #
      # @param [Integer] marker_lineno If it is equal to the `lineno`, then
      #   prepend a hashrocket. Otherwise, an empty marker.
      # @return [void]
      def add_marker(marker_lineno)
        tuple[0] =
          if lineno == marker_lineno
            " => #{ line }"
          else
            "    #{ line }"
          end
      end

      # Indents the `line` with +distance+ spaces.
      #
      # @param [Integer] distance
      # @return [void]
      def indent(distance)
        tuple[0] = "#{ ' ' * distance }#{ line }"
      end
    end

  end
end