{{/*
    BreadcrumbList Schema.org type.

    https://schema.org/BreadcrumbList
    https://developers.google.com/search/docs/appearance/structured-data/breadcrumb

    Google renders this in the result snippet in place of the raw URL, and it does NOT
    require a matching visible breadcrumb, so a site with params.options.breadCrumb off
    still benefits from it. Set params.options.breadCrumbSchema = false to suppress it.

    The trail comes from .Ancestors, Hugo's own page hierarchy, so there is nothing to
    configure and it cannot drift from the site structure. .Ancestors returns closest-first
    and includes the home page, hence .Reverse to put the root first.

    Known limitation: Google recommends a breadcrumb "represent a typical user path to a page,
    instead of mirroring the URL structure", and .Ancestors is by definition the URL structure.
    On a conventional site the two coincide. A site where they diverge, where readers reach a
    page by a route its URL does not describe, needs a hand-built trail and should override
    this partial rather than bend the content structure to fit it. Google supports several
    trails per page for exactly that case.

    Names come from .LinkTitle, which falls back to .Title. A section whose .Title is a long
    SEO title ("Blog – Brand") should set `linkTitle` in its front matter so the crumb stays
    short. That is Hugo's own key for exactly this, and header/breadcrumb.html reads it too,
    so renaming a section renames the visual trail and this schema together.

    The home crumb prefers an explicit `linkTitle` on the home page and falls back to
    site.Title. Not .LinkTitle: that silently falls back to .Title, and a home page's title is
    almost always a long SEO string rather than the name of the site, so reading it would put
    "Brand — the tagline that ranks" at the root of every trail. site.Title is the better
    default and is per-language on a multilingual site; a site wanting something else sets
    `linkTitle` on the home page and gets it.

    That root label is the one place this diverges from header/breadcrumb.html, which
    hardcodes the English string "Home". The chains themselves are identical: .Ancestors and
    that partial's .Parent recursion walk the same pages, verified in a build. A site
    rendering both may want to reconcile the two roots.

    .Permalink, not .RelPermalink: structured data needs absolute URLs. This is the opposite
    of head/google-tag.html, where a relative URL is what keeps deploy previews working.

    Built as a map and emitted in one interpolation, like the other schema partials here, so
    Hugo serialises the JSON and optional fields cannot leave a dangling comma.
*/}}
{{- $options := site.Params.options | default dict }}

{{- /* No trail on the home page: a single-item breadcrumb carries no information. Skipped
       on 404 and noindex pages too, where structured data can never be used. */ -}}
{{- if and (not .IsHome) (ne .Kind "404") (not .Params.noindex) (ne $options.breadCrumbSchema false) }}

  {{- $items := slice }}

  {{- range .Ancestors.Reverse }}
    {{- $ancestor := . }}
    {{- /* Skip an ancestor with no URL. A section carrying `build.render: never` is a real
           part of the hierarchy but was deliberately not published, so .Permalink is the
           empty string. Emitting the crumb anyway produced "item": "", which Google's Rich
           Results Test reports as a missing field, and `item` is required on every position
           except the last. Linking is impossible either way, so the level is dropped: a trail
           of pages that exist beats a trail with a hole in it.

           Positions renumber themselves because they come from len $items rather than from
           the loop index. */ -}}
    {{- with .Permalink }}
      {{- $items = $items | append (dict
        "@type" "ListItem"
        "position" (add (len $items) 1)
        "name" (cond $ancestor.IsHome (or $ancestor.Params.linkTitle site.Title) $ancestor.LinkTitle)
        "item" .
      ) }}
    {{- end }}
  {{- end }}

  {{- /* The page itself closes the trail. Google allows omitting the last item's URL, but
         including it costs nothing and keeps every entry the same shape. */ -}}
  {{- $items = $items | append (dict
    "@type" "ListItem"
    "position" (add (len $items) 1)
    "name" .LinkTitle
    "item" .Permalink
  ) }}

  {{- /* Guard rather than an assumption: every non-home page should have the home page as an
         ancestor, but a one-item list would be valid JSON-LD and useless, so do not emit it. */ -}}
  {{- if ge (len $items) 2 }}
    {{- $d := dict "@context" "https://schema.org" "@type" "BreadcrumbList" "itemListElement" $items }}
<script type="application/ld+json">
{{ $d }}
</script>
  {{- end }}

{{- end }}