{{- $capitalize := false -}}
{{- $slugs := .Params -}}
{{- if and (gt (len .Params) 0) (eq (index .Params 0) "upper") -}}
  {{- $capitalize = true -}}
  {{- $slugs = after 1 .Params -}}
{{- end -}}

{{- $links := slice -}}
{{- $firstIsSection := true -}}

{{- $paths := slice -}}
{{- range where $.Site.Pages "Slug" "in" $slugs -}}
  {{- if eq (len (where $.Site.Pages "Slug" .Slug)) 1 -}}
    {{- $paths = $paths | append .File.Path -}}
  {{- else -}}
    {{- errorf "Found more than one page with slug '%s'" .Slug -}}
  {{- end -}}
{{- end -}}
{{- if ne (len $paths) (len $slugs) -}}
  {{- errorf "Found %d pages but %d slugs were provided" (len $paths) (len $slugs) -}}
{{- end -}}

{{- with $.Site.GetPage (index $paths 0) -}}
  {{- $firstIsSection = .IsSection -}}
{{- end -}}

{{- range $paths -}}
  {{- with $.Site.GetPage . -}}
    {{- $isSection := .IsSection -}}
    {{- if ne $isSection $firstIsSection -}}
      {{- errorf "Cannot mix sections and regular pages in the same reference" -}}
    {{- end -}}
    {{- $weight := .Weight -}}
    {{- $slug := .Slug -}}
    {{- if $isSection -}}
      {{- $href := cond $.Site.Params.pdfgen (printf "#%s" $slug) .RelPermalink -}}
      {{- $link := printf `<a href="%s">%d</a>` $href $weight | safeHTML -}}
      {{- $links = $links | append $link -}}
    {{- else -}}
      {{- with .Parent -}}
        {{- $parentWeight := .Weight -}}
        {{- $href := cond $.Site.Params.pdfgen (printf "#%s" $slug) (printf "%s#%s" .RelPermalink $slug) -}}
        {{- $link := printf `<a href="%s">%d.%d</a>` $href $parentWeight $weight | safeHTML -}}
        {{- $links = $links | append $link -}}
      {{- end -}}
    {{- end -}}
  {{- end -}}
{{- end -}}

{{- $count := len $links -}}

{{- $prefix := "" -}}
{{- if $firstIsSection -}}
  {{- if eq $count 1 -}}
    {{- $prefix = "chapter " -}}
  {{- else -}}
    {{- $prefix = "chapters " -}}
  {{- end -}}
{{- else -}}
  {{- if eq $count 1 -}}
    {{- $prefix = "section " -}}
  {{- else -}}
    {{- $prefix = "sections " -}}
  {{- end -}}
{{- end -}}
{{- if $capitalize -}}
  {{- $prefix = $prefix | title -}}
{{- end -}}
{{- printf "<span>%s</span>" $prefix | safeHTML -}}

{{- if eq $count 1 -}}
  {{- index $links 0 -}}
{{- else if eq $count 2 -}}
  {{- index $links 0 -}}{{- print " and " | safeHTML -}}{{- index $links 1 -}}
{{- else -}}
  {{- range $i, $link := first (sub $count 1) $links -}}
    {{- $link -}}{{- print ", " | safeHTML -}}
  {{- end -}}
  {{- print "and " | safeHTML -}}{{- index $links (sub $count 1) -}}
{{- end -}}