require "iso-639"

module Asciidoctor
  module NIST
    class Converter < Standoc::Converter
      def metadata_id(node, xml)
        did = node.attr("docidentifier")
        dn = node.attr("docnumber")
        @series == "nist-cswp" && !node.attr("docnumber") and
          dn = Iso690Render.MMMddyyyy(node.attr("issued-date"))
        metadata_id_compose(node, xml, dn, did)
        xml.docnumber node.attr("docnumber") ||
          did&.sub(/^[^0-9]*/, "")&.sub(/[ -].*$/, "")
      end

      def unabbreviate(did)
        SERIES_ABBR.each { |k, v| did = did.sub(/^#{v} /, "#{k} ") }
        SERIES.each { |k, v| did = did.sub(/^#{k} /, "#{v} ") }
        did
      end

      def id_args(node, dn0)
        return nil unless dn0
        {
          id: dn0,
          series: node.attr("series"),
          edition: node.attr("edition"),
          version: node.attr("version"),
          revision: node.attr("revision"),
          update: node.attr("update"),
          year: (node.attr("copyright-year") || node.attr("updated-date") ||
                 node.attr("revdate") || node.attr("circulated-date") || 
                 Date.today.year.to_s).sub(/^(....).*$/, "\\1"),
          vol: node.attr("volume"),
          part: node.attr("part") || node.attr("part-number"),
          section: node.attr("section") || node.attr("section-number"),
          supplement: node.attr("supplement") || node.attr("supplement-number"),
          index: node.attr("index") || node.attr("index-number"),
          stage: node.attr("status") || node.attr("docstage"),
          iter: node.attr("iteration"),
          language: node.attr("language") || "en",
          date: /^draft/.match(node.attr("status") || node.attr("docstage")) ?
          (node.attr("circulated-date") || node.attr("revdate")) :
          node.attr("updated-date")
        }
      end

      def metadata_id_compose(node, xml, dn0, did)
        if did
          xml.docidentifier did, **attr_code(type: "NIST")
          xml.docidentifier unabbreviate(did), **attr_code(type: "nist-long")
        else
          args = id_args(node, dn0) || return
          xml.docidentifier add_id_parts(args, false), **attr_code(type: "NIST")
          xml.docidentifier add_id_parts(args, true),
            **attr_code(type: "nist-long")
          xml.docidentifier add_id_parts_mr(args), **attr_code(type: "nist-mr")
        end
      end

      def MMMddyyyy(isodate)
        return nil if isodate.nil?
        Date.parse(isodate).strftime("%B %d, %Y")
      end

      def status_abbr(stage, iter)
        IsoDoc::NIST::Metadata.new(nil, nil, @i18n).status_abbr(stage, iter)
      end

      def add_id_parts(args, long)
        args[:series] and series_name = long ?
          SERIES.dig(args[:series].to_sym) :
          SERIES_ABBR.dig(args[:series].to_sym)
        dn = (series_name || "NIST #{args[:series]}")  + " " + args[:id]
        dn += " Volume #{args[:vol]}" if args[:vol]
        dn += "," if args[:vol] && args[:revision]
        dn += " Revision #{args[:revision]}" if args[:revision]
        dn += "/Upd #{args[:update]}:#{args[:year]}" if args[:update]
        stage = status_abbr(args[:stage], args[:iter]) and dn += " (#{stage})"
        dn += " (#{MMMddyyyy(args[:date])})" if args[:date]
        dn
      end

      def id_parts_mr(args)
        part = []
        part << "v-#{args[:vol]}" if args[:vol]
        part << "pt-#{args[:part]}" if args[:part]
        part << "sec-#{args[:section]}" if args[:section]
        part << "sup-#{args[:supplement]}" if args[:supplement]
        part << "indx-#{args[:index]}" if args[:index]
        part
      end

      def id_editions_mr(args)
        part = []
        part << "e-#{args[:edition]}" if args[:edition]
        part << "r-#{args[:revision]}" if args[:revision]
        part << "ver-#{args[:version]}" if args[:version]
        part
      end

      def id_lang_mr(args)
        ret = args[:language].split(/,\s*/).map do |l|
          ISO_639.find(l).alpha3
        end.join(",")
      end

      def add_id_parts_mr(args)
        ret = ["NIST"]
        args[:series] and
          ret << SERIES_ABBR&.dig(args[:series].to_sym)&.sub(/^NIST /, "")
        stage = status_abbr(args[:stage], nil) || ""
        stage += "[-#{args[:iter]}]" if args[:iter]
        ret << stage unless stage.empty?
        ret << args[:id]
        ret += id_parts_mr(args)
        ret += id_editions_mr(args)
        ret << id_lang_mr(args)
        args[:update] and ret << "upd-#{args[:update]}:#{args[:year]}"
        ret.join(".")
      end
    end
  end
end