class TartanCloth

# File lib/tartancloth.rb, line 12
def initialize( markdown_file, title = nil )
  @markdown_file = markdown_file
  @title = title
end

# File lib/tartancloth.rb, line 53
def body_html
  bc = BlueCloth::new( File::read( @markdown_file ), header_labels: true )
  body = bc.to_html

  body = build_toc( body )
end

# File lib/tartancloth.rb, line 24
def to_html
  html = ""

  # Add a well formed HTML5 header.
  html << html_header(title)

  # Add the body content.
  html << body_html()

  # Add the document closing tags.
  html << html_footer()
end

# File lib/tartancloth.rb, line 41
def to_html_file( html_file )

  File.open( html_file, 'w') do |f|
    f << to_html()
  end
end

# File lib/tartancloth.rb, line 69
def build_toc( html_content )
  # Generate Nokogiri elements from HTML
  doc = Nokogiri::HTML::DocumentFragment.parse( html_content )

  # Make sure all header anchors are unique.
  make_header_anchors_unique(doc)

  # Find the TOC header
  toc = find_toc_header(doc)

  # Just return what was passed to us if there's no TOC.
  return html_content if toc.nil?

  # Get all headers in the document, starting from the TOC header.
  headers = get_headers(doc, toc)

  # Build the link info for the TOC.
  toc_links = []
  headers.each do |element|
    toc_links << link_hash(element)
  end

  # Convert link info to markdown.
  toc_md = toc_to_markdown(toc_links)

  # Convert the TOC markdown to HTML
  bc = BlueCloth::new( toc_md, pseudoprotocols: true )
  toc_content = bc.to_html

  # Convert the TOC HTML to Nokogiri elements.
  toc_html = Nokogiri::HTML::DocumentFragment.parse(toc_content)

  # Add toc class to the <ul> element
  toc_html.css('ul').add_class('toc')

  # Insert the TOC content before the toc element
  toc.before(toc_html.children)

  # Remove the TOC header placeholder element.
  toc.remove

  # Return the HTML
  doc.to_html
end

# File lib/tartancloth.rb, line 282
  def css()
    styles = <<CSS
<style media="screen" type="text/css">
<!--
  body {
    font-family: Arial, sans-serif;
  }

  .content {
    margin: 0 auto;
    min-height: 100%;
    padding: 0 0 100px;
    width: 980px;
    border: 1px solid #ccc;
    border-radius: 5px;
  }

  .rendered-content {
    padding: 10px;
  }

  /* Fancy HR styles based on http://css-tricks.com/examples/hrs/ */
  hr {
    border: 0;
    height: 1px;
    background-image: -webkit-linear-gradient(left, rgba(200,200,200,1), rgba(200,200,200,0.5), rgba(200,200,200,0));
    background-image:    -moz-linear-gradient(left, rgba(200,200,200,1), rgba(200,200,200,0.5), rgba(200,200,200,0));
    background-image:     -ms-linear-gradient(left, rgba(200,200,200,1), rgba(200,200,200,0.5), rgba(200,200,200,0));
    background-image:      -o-linear-gradient(left, rgba(200,200,200,1), rgba(200,200,200,0.5), rgba(200,200,200,0));
  }

  h1 {
    font-size: 24px;
    font-weight: normal;
    line-height: 1.25;
  }

  h2 {
    font-size: 20px;
    font-weight: normal;
    line-height: 1.5;
  }

  h3 {
    font-size: 16px;
    font-weight: bold;
    line-height: 1.5625;
  }

  h4 {
    font-size: 14px;
    font-weight: bold;
    line-height: 1.5;
  }

  h5 {
    font-size: 12px;
    font-weight: bold;
    line-height: 1.66;
    text-transform: uppercase;
  }

  h6 {
    font-size: 12px;
    font-style: italic;
    font-weight: bold;
    line-height: 1.66;
    text-transform: uppercase;
  }

  pre  {
    margin-left: 2em;
    display: block;
    background: #f5f5f5;
    font-family: monospace;
    border: 1px solid #ccc;
    border-radius: 2px;
    padding: 1px 3px;
  }

  code {
    background: #f5f5f5;
    font-family: monospace;
    border: 1px solid #ccc;
    border-radius: 2px;
    padding: 1px 3px;
  }

  pre, code {
    font-size: 12px;
    line-height: 1.4;
  }

  pre code {
    border: 0;
    padding: 0;
  }

  ul.toc li {
    list-style: none;
    font-size: 14px;
  }

  ul.toc li span.h3toc {
    margin-left: 20px;
  }

  ul.toc li span.h4toc {
    margin-left: 40px;
  }

  ul.toc li span.h5toc {
    margin-left: 60px;
  }

  ul.toc li span.h6toc {
    margin-left: 80px;
  }
-->
</style>
CSS
  end

# File lib/tartancloth.rb, line 134
def find_toc_header(doc)
  return nil unless doc

  doc.children.each do |element|
    return element if is_toc_header(element)
  end

  return nil
end

# File lib/tartancloth.rb, line 194
def get_anchor_for_header(element)
  # The previous element should be a simple anchor.
  # Get the actual link value from the anchor.
  anchor = element.previous_element
  anchor = nil unless anchor.name == 'a'
  anchor
end

# File lib/tartancloth.rb, line 163
def get_headers(doc, starting_element = nil)
  headers = []
  capture = (starting_element.nil? ? true : false)

  doc.children.each do |element|
    unless capture
      capture = true if element == starting_element
      next
    end # unless

    headers << element if is_header_element(element)
  end

  headers
end

# File lib/tartancloth.rb, line 207
def get_link(anchor)
  link = ""
  link = anchor.attributes['name'].value if anchor.name == 'a'
  link
end

# File lib/tartancloth.rb, line 407
  def html_footer()
    footer = <<HTML_FOOTER

      </div> <!-- .content -->
    </div> <!-- .rendered-content -->
  </body>
</html>
HTML_FOOTER
  end

# File lib/tartancloth.rb, line 262
  def html_header(title)
    styles = css()
    header = <<HTML_HEADER
<!DOCTYPE html>
<html>
  <head><title>#{title}</title></head>

  #{styles}

  <body>
    <div class="content">
      <div class="rendered-content">

HTML_HEADER
  end

# File lib/tartancloth.rb, line 146
def is_header_element(element)
  %w(h1 h2 h3 h4 h5 h6).include? element.name
end

# File lib/tartancloth.rb, line 152
def is_toc_header(element)
  return (is_header_element(element) && element.text == 'TOC')
end

# File lib/tartancloth.rb, line 184
def link_hash(element)
  anchor = get_anchor_for_header(element)
  anchor_link = get_link(anchor)

  # Store the header text (link text) and the anchor link and a class for styling.
  { text: element.text, link: anchor_link, klass: "#{element.name}toc" }
end

# File lib/tartancloth.rb, line 226
def make_header_anchors_unique(doc)
  headers = get_headers(doc)

  # Get anchors for each header.
  anchors = []
  headers.each do |h|
    anchors << get_anchor_for_header(h)
  end

  anchor_collection = {}
  anchors.each do |a|
    # Get the link
    link = get_link(a)

    # Get the current link count, will be nil if it's the first time.
    link_count = anchor_collection[link]

    if link_count.nil?
      # First time we've seen this link
      link_count = 0

      # Store it in the collection
      anchor_collection[link] = link_count
    else
      # Link already exists, modify it (add .#)
      set_link(a, "#{link}.#{link_count}")

      # Update the count for the next time we find this link
      anchor_collection[link] = link_count + 1
    end # if
  end
end

# File lib/tartancloth.rb, line 219
def set_link(anchor, link)
  anchor.attributes['name'].value = link if anchor.name == 'a'
end

# File lib/tartancloth.rb, line 119
def toc_to_markdown(toc_links)
  markdown = "## Table of Contents\n\n"
  toc_links.each do |link_data|
    text = link_data[:text]
    link = link_data[:link]
    klass = link_data[:klass]
    markdown << "+ [[#{text}](##{link})](class:#{klass})\n"
  end
  markdown << "\n"
end