{% capture headingsWorkspace %}
{% comment %}
  Version 1.0.5
    https://github.com/allejo/jekyll-anchor-headings

  "Be the pull request you wish to see in the world." ~Ben Balter

  Usage:
    {% include anchor_headings.html html=content %}

  Parameters:
    * html          (string) - the HTML of compiled markdown generated by kramdown in Jekyll

  Optional Parameters:
    * beforeHeading (bool)   : false  - Set to true if the anchor should be placed _before_ the heading's content
    * anchorAttrs   (string) :  ''    - Any custom HTML attributes that will be added to the `<a>` tag; you may NOT use `href`, `class` or `title`
    * anchorBody    (string) :  ''    - The content that will be placed inside the anchor; the `%heading%` placeholder is available
    * anchorClass   (string) :  ''    - The class(es) that will be used for each anchor. Separate multiple classes with a space
    * anchorTitle   (string) :  ''    - The `title` attribute that will be used for anchors
    * h_min         (int)    :  1     - The minimum header level to build an anchor for; any header lower than this value will be ignored
    * h_max         (int)    :  6     - The maximum header level to build an anchor for; any header greater than this value will be ignored
    * bodyPrefix    (string) :  ''    - Anything that should be inserted inside of the heading tag _before_ its anchor and content
    * bodySuffix    (string) :  ''    - Anything that should be inserted inside of the heading tag _after_ its anchor and content

  Output:
    The original HTML with the addition of anchors inside of all of the h1-h6 headings.
{% endcomment %}

{% assign minHeader = include.h_min | default: 1 %}
{% assign maxHeader = include.h_max | default: 6 %}
{% assign beforeHeading = include.beforeHeading %}
{% assign nodes = include.html | split: '<h' %}

{% capture edited_headings %}{% endcapture %}

{% for _node in nodes %}
  {% capture node %}{{ _node | strip }}{% endcapture %}

  {% if node == "" %}
    {% continue %}
  {% endif %}

  {% assign nextChar = node | replace: '"', '' | strip | slice: 0, 1 %}
  {% assign headerLevel = nextChar | times: 1 %}

  <!-- If the level is cast to 0, it means it's not a h1-h6 tag, so let's see if we need to fix it -->
  {% if headerLevel == 0 %}
    <!-- Split up the node based on closing angle brackets and get the first one. -->
    {% assign firstChunk = node | split: '>' | first %}

    <!-- If the first chunk does NOT contain a '<', that means we've broken another HTML tag that starts with 'h' -->
    {% unless firstChunk contains '<' %}
      {% capture node %}<h{{ node }}{% endcapture %}
    {% endunless %}

    {% capture edited_headings %}{{ edited_headings }}{{ node }}{% endcapture %}
    {% continue %}
  {% endif %}

  {% assign _workspace = node | split: '</h' %}
  {% assign _idWorkspace = _workspace[0] | split: 'id="' %}
  {% assign _idWorkspace = _idWorkspace[1] | split: '"' %}
  {% assign html_id = _idWorkspace[0] %}

  {% capture _hAttrToStrip %}{{ _workspace[0] | split: '>' | first }}>{% endcapture %}
  {% assign header = _workspace[0] | replace: _hAttrToStrip, '' %}

  <!-- Build the anchor to inject for our heading -->
  {% capture anchor %}{% endcapture %}

  {% if html_id and headerLevel >= minHeader and headerLevel <= maxHeader %}
    {% capture anchor %}href="#{{ html_id }}"{% endcapture %}

    {% if include.anchorClass %}
      {% capture anchor %}{{ anchor }} class="{{ include.anchorClass }}"{% endcapture %}
    {% endif %}

    {% if include.anchorTitle %}
      {% capture anchor %}{{ anchor }} title="{{ include.anchorTitle | replace: '%heading%', header }}"{% endcapture %}
    {% endif %}

    {% if include.anchorAttrs %}
      {% capture anchor %}{{ anchor }} {{ include.anchorAttrs }}{% endcapture %}
    {% endif %}

    {% capture anchor %}<a {{ anchor }}>{{ include.anchorBody | replace: '%heading%', header | default: '' }}</a>{% endcapture %}

    <!-- In order to prevent adding extra space after a heading, we'll let the 'anchor' value contain it -->
    {% if beforeHeading %}
      {% capture anchor %}{{ anchor }} {% endcapture %}
    {% else %}
      {% capture anchor %} {{ anchor }}{% endcapture %}
    {% endif %}
  {% endif %}

  {% capture new_heading %}
    <h{{ _hAttrToStrip }}
      {{ include.bodyPrefix }}
      {% if beforeHeading %}
        {{ anchor }}{{ header }}
      {% else %}
        {{ header }}{{ anchor }}
      {% endif %}
      {{ include.bodySuffix }}
    </h{{ _workspace | last }}
  {% endcapture %}
  {% capture edited_headings %}{{ edited_headings }}{{ new_heading }}{% endcapture %}
{% endfor %}
{% endcapture %}{% assign headingsWorkspace = '' %}{{ edited_headings | strip }}