require 'asciidoctor'
require 'asciidoctor/extensions'
require 'asciidoctor/converter/manpage'

module Asciidoctor
  class Converter::ManPageConverter
    alias orig_convert_inline_anchor convert_inline_anchor
    def convert_inline_anchor(node)
      case node.type
      when :xref
        return node.text if node.text
        refid = node.attributes['refid']
        'the section called “%s”' % refid.gsub('_', ' ')
      when :link
        return node.target if node.text == node.target
        doc = node.document

        footnote = doc.footnotes.find { |e| e.id == node.target }
        if !footnote
          footnote_text = "%s\n\e.RS\n\e\\%%%s\n\e.RE" % [node.text, node.target]
          index = doc.counter('footnote-number')
          footnote = Document::Footnote.new(index, node.target, footnote_text)
          doc.register(:footnotes, footnote)
        end

        "\e\\fB%s\e\\fR[%d]" % [node.text, footnote.index]
      else
        orig_convert_inline_anchor(node)
      end
    end
  end
end

module Git
  module Documentation
    class LinkGitProcessor < Asciidoctor::Extensions::InlineMacroProcessor
      use_dsl

      named :chrome

      def process(parent, target, attrs)
        prefix = parent.document.attr('git-relative-html-prefix')
        if parent.document.doctype == 'book'
          "<ulink url=\"#{prefix}#{target}.html\">" \
          "#{target}(#{attrs[1]})</ulink>"
        elsif parent.document.basebackend? 'html'
          %(<a href="#{prefix}#{target}.html">#{target}(#{attrs[1]})</a>)
        elsif parent.document.basebackend? 'manpage'
          "\e\\fB%s\e\\fR(%s)" % [target, attrs[1]]
        elsif parent.document.basebackend? 'docbook'
          "<citerefentry>\n" \
            "<refentrytitle>#{target}</refentrytitle>" \
            "<manvolnum>#{attrs[1]}</manvolnum>\n" \
          "</citerefentry>"
        end
      end
    end

    class DocumentPostProcessor < Asciidoctor::Extensions::Postprocessor
      def process document, output
        if document.basebackend? 'docbook'
          mansource = document.attributes['mansource']
          manversion = document.attributes['manversion']
          manmanual = document.attributes['manmanual']
          new_tags = "" \
            "<refmiscinfo class=\"source\">#{mansource}</refmiscinfo>\n" \
            "<refmiscinfo class=\"version\">#{manversion}</refmiscinfo>\n" \
            "<refmiscinfo class=\"manual\">#{manmanual}</refmiscinfo>\n"
          output = output.sub(/<\/refmeta>/, new_tags + "</refmeta>")
        end
        output
      end
    end
  end
end

Asciidoctor::Extensions.register do
  # Override attributes for man pages.
  # https://github.com/asciidoctor/asciidoctor/issues/4059
  tree_processor do
    process do |document|
      if document.backend == 'manpage'
        document.attributes.merge!({ 'litdd' => '\--', 'plus' => '+' })
      end
      document
    end
  end

  inline_macro Git::Documentation::LinkGitProcessor, :linkgit
  postprocessor Git::Documentation::DocumentPostProcessor
end