{{ $scratch := newScratch }}
{{ $productPathData := findRE "[^/]+.*?" .RelPermalink }}
{{ $product := index $productPathData 0 | default "influxdb" }}
{{ $minorVersions := (index .Site.Data.products $product).versions }}
{{ $currentVersion := index $productPathData 1 }}
{{ $latestVersion := (index .Site.Data.products $product).latest }}
{{ $majorVersion := index (findRE `v[0-9]` $currentVersion) 0 }}

{{ $scratch.Set "latestMinorVersion" "" }}
{{ if eq $majorVersion "v1"}}
  {{ $scratch.Set "latestMinorVersion" (index (last 1 (findRE `v1\.[0-9]{1,2}` (delimit $minorVersions " "))) 0) }}
{{ else if eq $majorVersion "v2" }}
  {{ $scratch.Set "latestMinorVersion" (index (last 1 (findRE `v2\.[0-9]{1,2}` (delimit $minorVersions " "))) 0) }}
{{ end }}

{{ $latestMinorVersion := $scratch.Get "latestMinorVersion" }}
{{ $baseURL := replaceRE `\/$` "" .Site.BaseURL }}

{{ $scratch.Set "canonicalURL" (print $baseURL .RelPermalink) }}

<!-- Override canonical URL with 'canonical' frontmatter, support latest shortcode -->
{{ if .Page.Params.canonical }}
  <!-- Support the latest shortcode in canonical overrides -->
  {{ if in .Page.Params.canonical "{{< latest" }}

    {{ $product := replaceRE `[ \"]` "" (index (findRE ` \"\w*\"` .Page.Params.canonical) 0) }}
    {{ $majorVersion := replaceRE `[ \"]` "" (index (findRE ` \"\w*\"` .Page.Params.canonical) 1) }}
    {{ $minorVersions := (index $.Site.Data.products $product).versions }}

    {{ $scratch.Set "latestVersion" (index $.Site.Data.products $product).latest }}
    {{ if gt (len $majorVersion) 0 }}
      {{ if eq $majorVersion "v1" }}
        {{ $scratch.Set "latestVersion" (index (last 1 (findRE `v1\.[0-9]{1,2}` (delimit $minorVersions " "))) 0) }}
      {{ else if eq $majorVersion "v2" }}
        {{ $scratch.Set "latestVersion" (index (last 1 (findRE `v2\.[0-9]{1,2}` (delimit $minorVersions " "))) 0) }}
      {{ end }}
    {{ end }}

    {{ $productLatestVersion := $scratch.Get "latestVersion" }}
    {{ $replaceLatest := replaceRE `\{\{\< latest \".*\" \>\}\}` (print $product "/" $productLatestVersion) .Page.Params.canonical }}
    {{ $scratch.Set "canonicalURL" (print $baseURL $replaceLatest) }}
  {{ else }}
    {{ $scratch.Set "canonicalURL" (print $baseURL .Page.Params.canonical) }}
  {{ end }}
<!-- InfluxDB OSS 2.0 vs Cloud canonical -->
<!-- If corresponding cloud page exists and uses duplicate-oss shortcode, set cloud to canonical -->
{{ else if and (eq $product "influxdb") (eq $currentVersion $latestVersion) }}
  {{ $correspondingPage := replaceRE `v2\.[0-9]{1,2}` "cloud" (print .Page.File) }}
  {{ if fileExists $correspondingPage }}
    {{ if (.Site.GetPage $correspondingPage).HasShortcode "duplicate-oss" }}
      {{ $scratch.Set "canonicalURL" (print $baseURL (.Site.GetPage $correspondingPage).RelPermalink) }}
    {{ end }}
  {{ end }}
<!-- Find the latest version of the page if canonical is not set and version is not cloud -->
{{ else if and (ge (len ($productPathData)) 2) (not (isset .Page.Params "canonical")) (ne $currentVersion "cloud") }}
  {{ range ( index $.Site.Data.products $product ).versions }}
    {{ $currentURL := $.Page.RelPermalink }}
    {{ if gt (len ($.GetPage ((replaceRE $currentVersion . $currentURL) | replaceRE `\/$` "")).Title) 0 }}
      {{ $scratch.Set "canonicalURL" (print $baseURL (replaceRE `v[0-9]\.[0-9]{1,2}` . $currentURL)) }}
    {{ end }}
  {{ end }}
{{ end }}

{{ $canonicalURL := $scratch.Get "canonicalURL" }}

<link rel="canonical" href="{{ $canonicalURL }}" />