# Fork from https://github.com/dafi/jekyll-toc-generator

#

# modify by mumu <github.com/mumuxme>

require 'nokogiri'

module Jekyll

module TOCGenerator

TOC_CONTAINER_HTML = '''

<div id="toc-container" class="hide-on-med-and-down">

<a href="#!" class="dropdown-button btn post-toc white teal-text" data-activates="dropdown-toc">

<i class="mdi mdi-menu-up right"></i><span class="">Content</span>

</a>

<ul id="dropdown-toc" class="dropdown-content">%1</ul>

</div>

'''

def toc_generate(html)

# No Toc can be specified on every single page

# For example the index page has no table of contents

no_toc = @context.environments.first["page"]["noToc"] || false;

return html if no_toc

config = @context.registers[:site].config

# Minimum number of items needed to show TOC, default 0 (0 means no minimum)

min_items_to_show_toc = config["minItemsToShowToc"] || 0

anchor_prefix = config["anchorPrefix"] || 'tocAnchor-'

# default top_tag set to h2

toc_top_tag = config["tocTopTag"] || 'h2'

toc_top_tag = toc_top_tag.gsub(/h/, '').to_i

toc_top_tag = 5 if toc_top_tag > 5

toc_sec_tag = toc_top_tag + 0 # simply change original `1` to `0`

toc_top_tag = "h#{toc_top_tag}"

toc_sec_tag = "h#{toc_sec_tag}"

# Text labels

hide_label = config["hideLabel"] || 'hide'

# show_label = config["showLabel"] || 'show' # unused

show_toggle_button = config["showToggleButton"]

toc_html = ''

toc_level = 1

toc_section = 1

item_number = 1

level_html = ''

doc = Nokogiri::HTML(html)

# Find H2 tag

doc.css(toc_top_tag).each do |tag|

# TODO This XPATH expression can greatly improved

ct = tag.xpath("count(following-sibling::#{toc_top_tag})")

sects = tag.xpath("following-sibling::#{toc_sec_tag}[count(following-sibling::#{toc_top_tag})=#{ct}]")

level_html = '';

inner_section = 0;

sects.map.each do |sect|

inner_section += 1;

anchor_id = [

anchor_prefix, toc_level, '-', toc_section, '-',

inner_section

].map(&:to_s).join ''

sect['id'] = "#{anchor_id}"

level_html += create_level_html(anchor_id,

toc_level + 1,

toc_section + inner_section,

item_number.to_s + '.' + inner_section.to_s,

sect.text,

'')

end

level_html = '<ul>' + level_html + '</ul>' if level_html.length > 0

anchor_id = anchor_prefix + toc_level.to_s + '-' + toc_section.to_s;

tag['id'] = "#{anchor_id}"

tag['class'] = 'section scrollspy' # For materialize scrollspy

toc_html += create_level_html(anchor_id,

toc_level,

toc_section,

item_number,

tag.text,

level_html);

toc_section += 1 + inner_section;

item_number += 1;

end

# for convenience item_number starts from 1

# so we decrement it to obtain the index count

toc_index_count = item_number - 1

return html unless toc_html.length > 0

if min_items_to_show_toc <= toc_index_count

toc_table = TOC_CONTAINER_HTML

.gsub('%1', toc_html);

doc.css('body').children.before(toc_table)

end

#doc.css('body').children.to_xhtml(indent:3, indent_text:" ")

doc.css('body').children.to_html()

end

private

def create_level_html(anchor_id, toc_level, toc_section, tocNumber, tocText, tocInner)

link = '<a href="#%1" class="link-toc"><span class="toctext">%2</span></a>%3'

.gsub('%1', anchor_id.to_s)

.gsub('%2', tocText)

.gsub('%3', tocInner ? tocInner : '');

'<li class="toc_level-%1 toc_section-%2">%3</li>'

.gsub('%1', toc_level.to_s)

.gsub('%2', toc_section.to_s)

.gsub('%3', link)

end

end

end

Liquid::Template.register_filter(Jekyll::TOCGenerator)