# Set of helpers to display the navigation sidebar
module SidebarHelpers
  def section_helper title: nil, selector: nil
    sect = Toc.instance.section(selector)
    @sect_def = Toc.instance.section_def(selector)
    str = "<li>
            <label class=\"tree-toggler level1\">
              #{collapsed_indicator(sect.collapsed?)}
              #{title}
            </label>"
    str += sect.has_subsections? ? nested_section(sect) : flat_section(sect)
    str + "</li>"
  end

  def nested_section sect
    sect.subsections.reduce("") {|acc, subs| acc + subsection_body(subs)}
  end

  def subsection_body sect
    "<ul class=\"tree\">
      <li>
        <label class=\"tree-toggler level2\">
          #{collapsed_indicator(sect.content.collapsed?)}
          #{sect.content.title}
        </label>
        #{subsection(sect, sect.content.collapsed?)}
      </li>
    </ul>"
  end

  def collapsed_indicator(coll)
    icon_markup(coll ? :plus : :minus)
  end

  def subsection(subsect, collapsed)
    disp_clause = collapsed ? "display: none" : "display: block"
    str = "<ul class=\"tree\" style=\"#{disp_clause}\">"
    str = subsect.children.reduce(str) { |acc, item| acc + subsection_item_link(item) }
    str + "</ul>"
  end

  def subsection_item_link tree_node
    bullet = @sect_def.options[:bullet]
    link_path = @items[tree_node.content.identifier].path
    "<li class=\"#{tree_node.content.css_class}\">#{icon_markup(bullet)}<a href=\"#{link_path}\">#{tree_node.content.title}</a></li>"
  end

  def flat_section sect
    disp_clause = sect.collapsed? ? "display: none" : "display: block"
    str = "<ul class=\"tree\" style=\"#{disp_clause}\">"
    str = sect.reduce(str) { |acc, item| acc + flat_section_item_link(item) }
    str + "</ul>"
  end

  def flat_section_item_link citem
    bullet = @sect_def.options[:bullet]
    path = @items[citem.identifier].path
    "<li class=\"#{citem.css_class}\">#{icon_markup(bullet)}<a href=\"#{path}\">#{citem.title}</a></li>"
  end

  def icon_markup icon_type
    return "" if icon_type.nil?
    css_class = {dash: "glyphicon-minus", star: "glyphicon-star", plus: "glyphicon-plus-sign", minus: "glyphicon-minus-sign"}.fetch(icon_type)
    "<span class=\"glyphicon #{css_class}\" style=#{STYLING_CONFIG[:bullet_style]}></span>"
  end
end