{{ $permalink_pretty := .Permalink | replaceRE "\\.html$" "/" }} <!-- Always have a trailing slash, even with uglyURLs enabled. -->
{{- with $.Params.images -}}
    <meta name="twitter:card" content="summary_large_image"/>
    <!-- As per https://developer.twitter.com/en/docs/tweets/optimize-with-cards/overview/summary-card-with-large-image,
         the required card property is "twitter:image", not "twitter:image:src". -->
    {{- $image := (index . 0) -}}
    {{ if (findRE "^/" $image) }} <!-- If image link has a leading slash -->
        <!-- Cannot use absURL below because it doesn't work as expected if baseURL has a subdir.
             See https://hugo-sandbox.netlify.com/subdir-canonify-true/ .
        -->
        {{ $baseurl_no_trailing_slash := $.Site.BaseURL | replaceRE "/$" "" }}
        <meta name="twitter:image" content="{{- (printf "%s%s" $baseurl_no_trailing_slash $image) -}}"/>
    {{- else -}}
        <meta name="twitter:image" content="{{- (printf "%s%s" $permalink_pretty $image) -}}"/>
    {{- end -}}
{{ else -}}
    {{- $images := $.Resources.ByType "image" -}}
    {{- $featured := $images.GetMatch "*feature*" -}}
    {{- $featured := cond (ne $featured nil) $featured ($images.GetMatch "{*cover*,*thumbnail*}") -}}
    {{- with $featured -}}
        <meta name="twitter:card" content="summary_large_image"/>
        <meta name="twitter:image" content="{{ $featured.Permalink }}"/>
    {{- else -}}
        <meta name="twitter:card" content="summary"/>
        {{- with $.Site.Params.images -}}
            {{- $image := (index . 0) -}}
            {{ if (findRE "^/" $image) }} <!-- If image link has a leading slash -->
                {{ $baseurl_no_trailing_slash := $.Site.BaseURL | replaceRE "/$" "" }}
                <meta name="twitter:image" content="{{- (printf "%s%s" $baseurl_no_trailing_slash $image) -}}"/>
            {{- else -}}
                <meta name="twitter:image" content="{{- (printf "%s%s" $permalink_pretty $image) -}}"/>
            {{- end -}}
        {{- end -}}
    {{- end -}}
{{- end }}
<meta name="twitter:title" content="{{ .Title }}"/>
<meta name="twitter:description" content="{{ with .Description }}{{ . | markdownify | plainify }}{{ else }}{{ if .IsPage }}{{ partial "summary_minus_toc.html" . | markdownify | plainify }}{{ else }}{{ with .Site.Params.description }}{{ . | markdownify | plainify }}{{ end }}{{ end }}{{ end -}}"/>
{{ with .Site.Social.twitter -}}
    <meta name="twitter:site" content="@{{ . }}"/>
    <meta name="twitter:creator" content="@{{ . }}"/>
{{ end -}}