tbpgr/gottani

# encoding: utf-8
require 'active_support/concern'

module Gottani
  # Gottani::Base
  module Base
    extend ActiveSupport::Concern
    attr_accessor :indent_char, :separator

    # ClassMethods
    module ClassMethods
      def define_to_common(base)
        define_method "#{base}_to_common".to_sym do |text|
          to_common text
        end
        alias_method "to_#{base}".to_sym, :to_indent_text
      end
    end

    def initialize
      @indent_char = indent_char
      @zero_start = zero_start?
      @separator = separator
    end

    def to_common(text)
      text.each_line.reduce([]) do |ret, line|
        chopped = line.chop
        line_hash = {}
        level = zero_start? ? indent_level(chopped) - 1 : indent_level(chopped)
        line_hash[:level] = level
        line_hash[:value] = indentless_line(chopped)
        line_hash[:value].gsub!(/^#{@separator}/, '') unless @separator.nil?
        ret << line_hash
        ret
      end
    end

    def to_indent_text(common)
      common.reduce([]) do |ret, line|
        level = zero_start? ? line[:level] + 1 : line[:level]
        indent = @indent_char * level
        indent += @separator unless @separator.nil?
        ret << "#{indent}#{line[:value]}"
      end.join("\n") + "\n"
    end

    private

    def indent_level(line)
      prefix_indents = line.scan(/^#{@indent_char}*/).first
      prefix_indents = prefix_indents.nil? ? '' : prefix_indents
      prefix_indents.scan(@indent_char).size
    end

    def indentless_line(chopped_line)
      chopped_line.gsub(/^#{@indent_char}*/, '')
    end
  end
end