require "date"
require "nokogiri"
require "pathname"
require "open-uri"
require "pp"
require_relative "./cleanup_block.rb"
require_relative "./cleanup_ref.rb"

module Asciidoctor
  module ISO
    module Cleanup
      def textcleanup(text)
        text.gsub(/\s+<fn /, "<fn ")
      end

      def cleanup(xmldoc)
        sections_cleanup(xmldoc)
        obligations_cleanup(xmldoc)
        termdef_cleanup(xmldoc)
        table_cleanup(xmldoc)
        formula_cleanup(xmldoc)
        figure_cleanup(xmldoc)
        ref_cleanup(xmldoc)
        note_cleanup(xmldoc)
        normref_cleanup(xmldoc)
        reference_names(xmldoc)
        xref_cleanup(xmldoc)
        bpart_cleanup(xmldoc)
        quotesource_cleanup(xmldoc)
        para_cleanup(xmldoc)
        callout_cleanup(xmldoc)
        origin_cleanup(xmldoc)
        element_name_cleanup(xmldoc)
        footnote_renumber(xmldoc)
        empty_element_cleanup(xmldoc)
        bookmark_cleanup(xmldoc)
        xmldoc
      end

      TEXT_ELEMS =
        %w{status language script version author name callout phone
           email street city state country postcode identifier referenceFrom
           referenceTo docidentifier prefix initial addition surname forename
           title draft secretariat title-main title-intro title-part}.freeze

      def empty_element_cleanup(xmldoc)
        xmldoc.xpath("//" + TEXT_ELEMS.join(" | //")).each do |x|
          x.remove if x.children.empty?
        end
      end

      def element_name_cleanup(xmldoc)
        xmldoc.traverse { |n| n.name = n.name.gsub(/_/, "-") }
      end

      def link_callouts_to_annotations(callouts, annotations)
        callouts.each_with_index do |c, i|
          c["target"] = "_" + UUIDTools::UUID.random_create
          annotations[i]["id"] = c["target"]
        end
      end

      def align_callouts_to_annotations(xmldoc)
        xmldoc.xpath("//sourcecode").each do |x|
          callouts = x.elements.select { |e| e.name == "callout" }
          annotations = x.elements.select { |e| e.name == "annotation" }
          if callouts.size == annotations.size
            link_callouts_to_annotations(callouts, annotations)
          else
            warn "#{x['id']}: mismatch of callouts and annotations"
          end
        end
      end

      def merge_annotations_into_sourcecode(xmldoc)
        xmldoc.xpath("//sourcecode").each do |x|
          while x&.next_element&.name == "annotation"
            x.next_element.parent = x
          end
        end
      end

      def callout_cleanup(xmldoc)
        merge_annotations_into_sourcecode(xmldoc)
        align_callouts_to_annotations(xmldoc)
      end

      def termdef_stem_cleanup(xmldoc)
        xmldoc.xpath("//term/p/stem").each do |a|
          if a.parent.elements.size == 1
            # para containing just a stem expression
            t = Nokogiri::XML::Element.new("admitted", xmldoc)
            parent = a.parent
            t.children = a.remove
            parent.replace(t)
          end
        end
      end

      def termdomain_cleanup(xmldoc)
        xmldoc.xpath("//p/domain").each do |a|
          prev = a.parent.previous
          prev.next = a.remove
        end
      end

      def termdefinition_cleanup(xmldoc)
        xmldoc.xpath("//term").each do |d|
          first_child = d.at("./p | ./figure | ./formula") || return
          t = Nokogiri::XML::Element.new("definition", xmldoc)
          first_child.replace(t)
          t << first_child.remove
          d.xpath("./p | ./figure | ./formula").each { |n| t << n.remove }
        end
      end

      def termdef_unnest_cleanup(xmldoc)
        # release termdef tags from surrounding paras
        nodes = xmldoc.xpath("//p/admitted | //p/deprecates")
        while !nodes.empty?
          nodes[0].parent.replace(nodes[0].parent.children)
          nodes = xmldoc.xpath("//p/admitted | //p/deprecates")
        end
      end

      def termdef_boilerplate_cleanup(xmldoc)
        xmldoc.xpath("//terms/p | //terms/ul").each do |a|
          a.remove
        end
      end

      def termdef_cleanup(xmldoc)
        termdef_unnest_cleanup(xmldoc)
        termdef_stem_cleanup(xmldoc)
        termdomain_cleanup(xmldoc)
        termdefinition_cleanup(xmldoc)
        termdef_boilerplate_cleanup(xmldoc)
      end

      ELEMS_ALLOW_NOTES =
        %w[p formula quote sourcecode example admonition ul ol dl figure].freeze

      # if a note is at the end of a section, it is left alone
      # if a note is followed by a non-note block,
      # it is moved inside its preceding block
      def note_cleanup(xmldoc)
        q = "//note[following-sibling::*[not(local-name() = 'note')]]"
        xmldoc.xpath(q).each do |n|
          next unless n.ancestors("table").empty?
          prev = n.previous_element || next
          n.parent = prev if ELEMS_ALLOW_NOTES.include? prev.name
        end
      end

      def empty_text_before_first_element(x)
        x.children.each do |c|
          if c.text?
            return false if /\S/.match?(c.text)
          end
          return true if c.element?
        end
        true
      end

      def strip_initial_space(x)
        if x.children[0].text?
          if !/\S/.match?(x.children[0].text)
            x.children[0].remove
          else
            x.children[0].content =  x.children[0].text.gsub(/^ /, "")
          end
        end
      end

      def bookmark_cleanup(xmldoc)
        xmldoc.xpath("//li[descendant::bookmark]").each do |x|
          if x&.elements[0]&.name == "p" &&
              x&.elements[0]&.elements[0]&.name == "bookmark"
            if empty_text_before_first_element(x.elements[0])
              x["id"] = (x.elements[0].elements[0].remove)["id"]
              strip_initial_space(x.elements[0])
            end
          end
        end
      end
    end
  end
end