module IsoDoc::Ietf
  class RfcConvert < ::IsoDoc::Convert
    def common_rfc_pis(node)
      rfc_pis = {
         artworkdelimiter: node&.at(ns("//pi/artworkdelimiter"))&.text,
        artworklines: node&.at(ns("//pi/artworklines"))&.text,
        authorship: node&.at(ns("//pi/authorship"))&.text,
        autobreaks: node&.at(ns("//pi/autobreaks"))&.text,
        background: node&.at(ns("//pi/background"))&.text,
        colonspace: node&.at(ns("//pi/colonspace"))&.text,
        comments: node&.at(ns("//pi/comments"))&.text,
        docmapping: node&.at(ns("//pi/docmapping"))&.text,
        editing: node&.at(ns("//pi/editing"))&.text,
        emoticonic: node&.at(ns("//pi/emoticonic"))&.text,
        footer: node&.at(ns("//pi/footer"))&.text,
        header: node&.at(ns("//pi/header"))&.text,
        inline: node&.at(ns("//pi/inline"))&.text,
        iprnotified: node&.at(ns("//pi/iprnotified"))&.text,
        linkmailto: node&.at(ns("//pi/linkmailto"))&.text,
        linefile: node&.at(ns("//pi/linefile"))&.text,
        notedraftinprogress: node&.at(ns("//pi/notedraftinprogress"))&.text,
        private: node&.at(ns("//pi/private"))&.text,
        refparent: node&.at(ns("//pi/refparent"))&.text,
        rfcedstyle: node&.at(ns("//pi/rfcedstyle"))&.text,
        slides: node&.at(ns("//pi/slides"))&.text,
        "text-list-symbols": node&.at(ns("//pi/text-list-symbols"))&.text,
        tocappendix: node&.at(ns("//pi/tocappendix"))&.text,
        tocindent: node&.at(ns("//pi/tocindent"))&.text,
        tocnarrow: node&.at(ns("//pi/tocnarrow"))&.text,
        tocompact: node&.at(ns("//pi/tocompact"))&.text,
        topblock: node&.at(ns("//pi/topblock"))&.text,
        useobject: node&.at(ns("//pi/useobject"))&.text,
        strict: node&.at(ns("//pi/strict"))&.text || "yes",
        compact: node&.at(ns("//pi/compact"))&.text || "yes",
        subcompact: node&.at(ns("//pi/subcompact"))&.text || "no",
        toc: node&.at(ns("//pi/toc-include"))&.text,
        tocdepth: node&.at(ns("//pi/toc-depth"))&.text || "4",
        symrefs: node&.at(ns("//pi/sym-refs"))&.text || "yes",
        sortrefs: node&.at(ns("//pi/sort-refs"))&.text || "yes",
      }
      attr_code(rfc_pis)
    end

    def set_pis(node, doc)
      rfc_pis = common_rfc_pis(node)
      rfc_pis.each_pair do |k, v|
        pi = Nokogiri::XML::ProcessingInstruction.new(doc, "rfc",
                                                      "#{k}=\"#{v}\"")
        doc.root.add_previous_sibling(pi)
      end
      doc.to_xml
    end

    def rfc_attributes(docxml)
      t = Time.now.getutc
      obs = xpath_comma(docxml.xpath(ns(
        "//bibdata/relation[@type = 'obsoletes']/bibitem/docidentifier")))
      upd = xpath_comma(docxml.xpath(ns(
        "//bibdata/relation[@type = 'updates']/bibitem/docidentifier")))
      {
        docName:        @meta.get[:doctype] == "Internet Draft" ? @meta.get[:docnumber] : nil,
        number:         @meta.get[:doctype].casecmp?("rfc") ? @meta.get[:docnumber] : nil,
        category:       docxml&.at(ns("//bibdata/series[@type = 'intended']/title"))&.text || "std",
        ipr:            docxml&.at(ns("//bibdata/ext/ipr"))&.text,
        obsoletes:      obs,
        updates:        upd,
        indexInclude:   docxml&.at(ns("//bibdata/ext/indexInclude"))&.text,
        iprExtract:     docxml&.at(ns("//bibdata/ext/iprExtract"))&.text,
        sortRefs:       docxml&.at(ns("//bibdata/ext/sortRefs"))&.text,
        symRefs:        docxml&.at(ns("//bibdata/ext/symRefs"))&.text,
        tocInclude:     docxml&.at(ns("//bibdata/ext/tocInclude"))&.text,
        tocDepth:       docxml&.at(ns("//bibdata/ext/tocDepth"))&.text,
        submissionType: docxml&.at(ns(
          "//bibdata/series[@type = 'stream']/title"))&.text || "IETF",
        'xml:lang':     docxml&.at(ns("//bibdata/language"))&.text,
        version:        "3",
        'xmlns:xi':        "http://www.w3.org/2001/XInclude",
        prepTime:       sprintf("%04d-%02d-%02dT%02d:%02d:%02dZ",
                                t.year, t.month, t.day, t.hour, t.min, t.sec),
      }
    end

    def xpath_comma(xpath)
      return nil if xpath.empty?
      xpath.map { |x| x.text }.join(", ")
    end

    def make_link(out, isoxml)
      links = isoxml.xpath(ns(
        "//bibdata/relation[@type = 'includedIn' or @type = 'describedBy' or "\
        "@type = 'derivedFrom' or @type = 'equivalent']")) || return
        links.each do |l|
          out.link **{ href: l&.at(ns("./bibitem/docidentifier"))&.text,
                       rel: rel2iana(l["type"]) }
        end
    end

    def rel2iana(type)
      case type
      when "includedIn" then "item"
      when "describedBy" then "describedby"
      when "derivedFrom" then "convertedfrom"
      when "equivalent" then "alternate"
      else 
        "alternate"
      end
    end

    def make_middle(out, isoxml)
      out.middle do |middle|
        clause isoxml, middle
      end
    end

    def make_back(out, isoxml)
      out.back do |back|
        annex isoxml, back
        bibliography isoxml, back
      end
    end

    def clause_parse_title(node, div, c1, out)
      return unless c1
      div.name do |n|
        c1&.children&.each { |c2| parse(c2, n) }
      end
    end

    def clause_parse(node, out)
      out.section **attr_code( anchor: node["id"], numbered: node["numbered"],
                              removeInRFC: node["removeInRFC"], toc: node["toc"]) do |div|
        clause_parse_title(node, div, node.at(ns("./title")), out)
        node.children.reject { |c1| c1.name == "title" }.each do |c1|
          parse(c1, div)
        end
      end
    end

    def clause(isoxml, out)
      isoxml.xpath("//xmlns:preface/child::*[not(name() = 'abstract' or name() = 'foreword')] "\
                   "| //xmlns:sections/child::*").each do |c|
        clause1(c, out)
      end
    end

    def clause1(c, out)
      out.section **attr_code( anchor: c["id"], numbered: c["numbered"],
                              removeInRFC: c["removeInRFC"], toc: c["toc"]) do |div|
        clause_parse_title(c, div, c.at(ns("./title")), out)
        c.elements.reject { |c1| c1.name == "title" }.each do |c1|
          parse(c1, div)
        end
      end
    end

    def annex(isoxml, out)
      isoxml.xpath(ns("//annex")).each do |c|
        clause1(c, out)
      end
    end
  end
end