require 'asciidoctor/extensions'

class AngularLocalizerTreeprocessor < Asciidoctor::Extensions::Treeprocessor
  def process document
    document.blocks? ? (localize_blocks document) : nil
  end

  def localize_blocks node
    node.find_by do |b|
      if b.content_model == :simple
        b.lines[0] = %({{"#{b.lines[0]})
        b.lines[-1] = %(#{b.lines[-1]}" | localize}})
      elsif b.context == :list_item
        replace_instance_text b
      elsif b.context == :table
        replace_text = lambda do |r|
          r.each do |c|
            replace_instance_text c
          end
        end

        b.rows.head.each(&replace_text)
        b.rows.body.each(&replace_text)
        b.rows.foot.each(&replace_text)
      end

      # Required for asciidoctor <= 1.5.5
      if b.instance_variable_defined?(:@subbed_title)
        b.remove_instance_variable :@subbed_title
      end

      replace_instance_text b, :@title

      true
    end
    nil
  end

  def replace_instance_text node, prop=:@text
    text = node.instance_variable_get prop
    node.instance_variable_set prop, (localize_text text) unless text.to_s.empty?
  end

  def localize_text text
    %({{"#{text}"| localize}})
  end
end

Asciidoctor::Extensions.register do
  treeprocessor AngularLocalizerTreeprocessor
end