unless RUBY_ENGINE == 'opal'
  # This helper file borrows from the Bespoke converter
  # https://github.com/asciidoctor/asciidoctor-bespoke
  require 'asciidoctor'
end

# This module gets mixed in to every node (the context of the template) at the
# time the node is being converted. The properties and methods in this module
# effectively become direct members of the template.
module Slim::Helpers

  EOL = %(\n)
  SliceHintRx = /  +/

  def slice_text str, active = nil
    if (active || (active.nil? && (option? :slice))) && (str.include? '  ')
      (str.split SliceHintRx).map {|line| %(<span class="line">#{line}</span>) }.join EOL
    else
      str
    end
  end

  def to_boolean val
    val && val != 'false' && val.to_s != '0' || false
  end

  # false needs to be verbatim everything else is a string.
  # Calling side isn't responsible for quoting so we are doing it here
  def to_valid_slidenumber val
    # corner case: empty is empty attribute which is true
    return true if val == ""
    # using to_s here handles both the 'false' string and the false boolean
    val.to_s == 'false' ? false : "'#{val}'"
  end

  ##
  # These constants and functions are from the asciidictor-html5s project
  # https://github.com/jirutka/asciidoctor-html5s/blob/a71db48a1dd5196b668b3a3d93693c5d877c5bf3/data/templates/helpers.rb

  # Defaults
  DEFAULT_TOCLEVELS = 2
  DEFAULT_SECTNUMLEVELS = 3


  VOID_ELEMENTS = %w(area base br col command embed hr img input keygen link
                     meta param source track wbr)

  ##
  # Creates an HTML tag with the given name and optionally attributes. Can take
  # a block that will run between the opening and closing tags.
  #
  # @param name [#to_s] the name of the tag.
  # @param attributes [Hash] (default: {})
  # @param content [#to_s] the content; +nil+ to call the block. (default: nil).
  # @yield The block of Slim/HTML code within the tag (optional).
  # @return [String] a rendered HTML element.
  #

  def html_tag(name, attributes = {}, content = nil)
    attrs = attributes.inject([]) do |attrs, (k, v)|
      next attrs if !v || v.nil_or_empty?
      v = v.compact.join(' ') if v.is_a? Array
      attrs << (v == true ? k : %(#{k}="#{v}"))
    end
    attrs_str = attrs.empty? ? '' : ' ' + attrs.join(' ')


    if VOID_ELEMENTS.include? name.to_s
      %(<#{name}#{attrs_str}>)
    else
      content ||= yield if block_given?
      %(<#{name}#{attrs_str}>#{content}</#{name}>)
    end
  end


  ##
  # Returns corrected section level.
  #
  # @param sec [Asciidoctor::Section] the section node (default: self).
  # @return [Integer]
  #
  def section_level(sec = self)
    @_section_level ||= (sec.level == 0 && sec.special) ? 1 : sec.level
  end


  ##
  # Returns the captioned section's title, optionally numbered.
  #
  # @param sec [Asciidoctor::Section] the section node (default: self).
  # @return [String]
  #
  def section_title(sec = self)
    sectnumlevels = document.attr(:sectnumlevels, DEFAULT_SECTNUMLEVELS).to_i

    if sec.numbered && !sec.caption && sec.level <= sectnumlevels
      [sec.sectnum, sec.captioned_title].join(' ')
    else
      sec.captioned_title
    end
  end


  # Between delimiters (--) is code taken from asciidoctor-bespoke 1.0.0.alpha.1
  # Licensed under MIT, Copyright (C) 2015-2016 Dan Allen and the Asciidoctor Project
  #--
  # Retrieve the converted content, wrap it in a `<p>` element if
  # the content_model equals :simple and return the result.
  #
  # Returns the block content as a String, wrapped inside a `<p>` element if
  # the content_model equals `:simple`.
  def resolve_content
    @content_model == :simple ? %(<p>#{content}</p>) : content
  end
  #--

end

# More custom functions can be added in another namespace if required
#module Helpers
#end