{{ $orientation := 0 }}

{{ with .Params.orientation }}
    {{ if strings.Contains . "horizontal" }}
        {{ $orientation = 0 }}
    {{ else if strings.Contains . "rotate180" }}
        {{ $orientation = 180 }}
    {{ else if strings.Contains . "rotate90" }}
        {{ $orientation = 90 }}
    {{ else if strings.Contains . "rotate270" }}
        {{ $orientation = 270 }}
    {{ end }}
{{ else }}
    {{ with (int .Exif.Tags.Orientation) }}
        {{/* EXIF orientation is specified as an integer corresponding to a 90º rotation. */}}
        {{ if in (slice 1 2) . }}
            {{ $orientation = 0 }}
        {{ else if in (slice 3 4) . }}
            {{ $orientation = 180 }}
        {{ else if in (slice 5 6) . }}
            {{ $orientation = 90 }}
        {{ else if in (slice 7 8) . }}
            {{ $orientation = 270 }}
        {{ end }}
    {{ else }}
        {{ warnf "Image missing orientation: %s" . }}
    {{ end }}
{{ end }}

{{ return $orientation }}