{{/* Table of Contents */}}
{{/* TODO: toc bottom part should be able to hide */}}
{{- $toc := .Params.toc | default true -}}
{{- $onThisPage := (T "onThisPage") | default "On this page"}}
{{- $editThisPage := (T "editThisPage") | default "Edit this page"}}
{{- $backToTop := (T "backToTop") | default "Scroll to top" -}}

<nav class="hextra-toc hx-order-last hx-hidden hx-w-64 hx-shrink-0 xl:hx-block print:hx-hidden hx-px-4" aria-label="table of contents">
  {{- if $toc }}
    <div class="hextra-scrollbar hx-sticky hx-top-16 hx-overflow-y-auto hx-pr-4 hx-pt-6 hx-text-sm [hyphens:auto] hx-max-h-[calc(100vh-var(--navbar-height)-env(safe-area-inset-bottom))] ltr:hx--mr-4 rtl:hx--ml-4">
      {{- with .Fragments.Headings -}}
        <p class="hx-mb-4 hx-font-semibold hx-tracking-tight">{{ $onThisPage }}</p>
        {{- range . -}}
          <ul>
            {{- with .Headings -}}{{ template "toc-subheading" (dict "headings" . "level" 0) }}{{- end -}}
          </ul>
        {{- end -}}
      {{- end -}}

      {{- $borderClass := "hx-mt-8 hx-border-t hx-bg-white hx-pt-8 hx-shadow-[0_-12px_16px_white] dark:hx-bg-dark dark:hx-shadow-[0_-12px_16px_#111]" -}}
      {{- if not .Fragments.Headings -}}
        {{- $borderClass = "" -}}
      {{- end -}}

      {{/* TOC bottom part */}}
      <div class="{{ $borderClass }} hx-sticky hx-bottom-0 hx-flex hx-flex-col hx-items-start hx-gap-2 hx-pb-8 dark:hx-border-neutral-800 contrast-more:hx-border-t contrast-more:hx-border-neutral-400 contrast-more:hx-shadow-none contrast-more:dark:hx-border-neutral-400">
        {{- if site.Params.editURL.enable -}}
          {{- $editURL := site.Params.editURL.base | default "" -}}
          {{- with .Params.editURL -}}
            {{/* if `editURL` is set in the front matter */}}
            {{- $editURL = . -}}
          {{- else -}}
            {{- with .File -}}
              {{/* `.FileInfo.Meta.SourceRoot` is a Hugo internal field, e.g. `/path/to/repo/content/en/` */}}
              {{- $sourceDir := replace (strings.TrimPrefix .FileInfo.Meta.BaseDir .FileInfo.Meta.SourceRoot) "\\" "/" -}}
              {{- $sourceDir = strings.TrimPrefix "/content" $sourceDir -}}
              {{- $path := replace .Path "\\" "/" -}}
              {{- $editURL = urls.JoinPath $editURL $sourceDir $path -}}
            {{- end -}}
          {{- end -}}
          <a class="hx-text-xs hx-font-medium hx-text-gray-500 hover:hx-text-gray-900 dark:hx-text-gray-400 dark:hover:hx-text-gray-100 contrast-more:hx-text-gray-800 contrast-more:dark:hx-text-gray-50" href="{{ $editURL }}" target="_blank" rel="noreferrer">{{ $editThisPage }}</a>
        {{- end -}}
        {{/* Scroll To Top */}}
        <button aria-hidden="true" id="backToTop" onClick="scrollUp();" class="hx-transition-all hx-duration-75 hx-opacity-0 hx-text-xs hx-font-medium hx-text-gray-500 hover:hx-text-gray-900 dark:hx-text-gray-400 dark:hover:hx-text-gray-100 contrast-more:hx-text-gray-800 contrast-more:dark:hx-text-gray-50">
          <span>
            {{- $backToTop -}}
          </span>
          <svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="1.5" stroke="currentColor" class="hx-inline ltr:hx-ml-1 rtl:hx-mr-1 hx-h-3.5 hx-w-3.5 hx-border hx-rounded-full hx-border-gray-500 hover:hx-border-gray-900 dark:hx-border-gray-400 dark:hover:hx-border-gray-100 contrast-more:hx-border-gray-800 contrast-more:dark:hx-border-gray-50">
            <path stroke-linecap="round" stroke-linejoin="round" d="M4.5 15.75l7.5-7.5 7.5 7.5" />
          </svg>
        </button>
      </div>
    </div>
  {{ end -}}
</nav>

{{/* TOC subheadings component. This is a recursive component that renders a list of headings. */}}
{{- define "toc-subheading" -}}
  {{- $headings := .headings -}}
  {{- $level := .level -}}
  {{- if ge $level 6 -}}
    {{ return }}
  {{- end -}}

  {{- $padding := (mul $level 4) -}}
  {{- $class := cond (eq $level 0) "hx-font-semibold" (printf "ltr:hx-pl-%d rtl:hx-pr-%d" $padding $padding) -}}

  {{- range $headings }}
    {{- if .Title }}
      <li class="hx-my-2 hx-scroll-my-6 hx-scroll-py-6">
        <a class="{{ $class }} hx-inline-block hx-text-gray-500 hover:hx-text-gray-900 dark:hx-text-gray-400 dark:hover:hx-text-gray-300 contrast-more:hx-text-gray-900 contrast-more:hx-underline contrast-more:dark:hx-text-gray-50 hx-w-full hx-break-words" href="#{{ anchorize .ID }}">
          {{- .Title | safeHTML | plainify | htmlUnescape }}
        </a>
      </li>
    {{- end -}}
    {{- with .Headings -}}
      {{ template "toc-subheading" (dict "headings" . "level" (add $level 1)) }}
    {{- end -}}

  {{- end -}}
{{- end -}}
