dotfiles-ansible/roles/scripts/templates/preview.j2

#!/bin/bash

_cache_thumbnail() {
	thumbnail_dir="${XDG_CACHE_HOME:-$HOME/.cache}/thumbnails"
	[ ! -d "${thumbnail_dir}" ] && mkdir -p "${thumbnail_dir}"

	tmpfile="${thumbnail_dir}/$(stat -c '%n%i%F%s%Y' -- "$(readlink -f "$2")" | sha256sum | awk '{print $1}').jpg"
	if [ ! -f "$tmpfile" ]; then
		case "$1" in
			video)
				ffmpegthumbnailer -i "$2" -o "$tmpfile" -s 0
				;;
			font)
				read -r -d '' font_preview_text <<-EOF
				ABCDEFGHIJKLM
				NOPQRSTUVWXYZ
				abcdefghijklm
				nopqrstuvwxyz
				1234567890
				!@$\%<>(){}[]
				== != => <=
				愛してるおかえりなさい
				EOF
				convert -size 900x900 xc:"{{ colors.background }}" \
					-gravity center \
					-pointsize 40 \
					-font "$2" \
					-fill "{{ colors.white2 }}" \
					-annotate +0+0 "$font_preview_text" \
					-flatten "$tmpfile"
				;;
		esac
	fi

	# Return the location
	printf "%s" "$tmpfile"
}

_preview_markdown() {
	mdcat "$1" || glow -s ~/.config/glow/styles/{{ theme }}.json "$1" || lowdown -t term "$1"
}

_preview_image() {
	chafa --animate=off --polite=on --size="$2"x"$3" "$1" || exiftool "$1"
}

_preview_video() {
	_preview_image "$(_cache_thumbnail video "$1")" "$2" "$3" || fprobe -hide_banner -pretty "$1" || exiftool "$1"
}

_preview_font() {
	_preview_image "$(_cache_thumbnail font "$1")" "$2" "$3" || exiftool "$1"
}

# Take 2 additional arguments as width and height (rows/cols)
FILE="$1"
WIDTH="$2"
HEIGHT="$3"

mimetype=$(file --dereference --brief --mime-type -- "$FILE")
filename="$(basename "$FILE")"

if [[ $mimetype == inode/directory ]]; then
	# Don't preview the inode ../
	if [ -z "${FILE##*/..*}" ]; then
		echo ""
	else
		lsd -1FAL --group-dirs first --icon always --color always "$FILE"
	fi
	exit
fi

if [[ $mimetype == @(image/vnd.djvu?(+multipage)|image/x-djvu) ]]; then
	djvutxt "$FILE" || exiftool "$FILE"
	exit
fi

if [[ $mimetype == image/* ]]; then
	_preview_image "$FILE" "$WIDTH" "$HEIGHT"; exit
fi

if [[ $mimetype == video/* ]]; then
	_preview_video "$FILE" "$WIDTH" "$HEIGHT"; exit
fi

if [[ $mimetype == audio/* ]]; then
	fprobe -hide_banner -pretty "$FILE" || exiftool "$FILE"
	exit
fi

if [[ $mimetype == @(font/*|application/x-font*|application/vnd.ms-opentype) ]]; then
	_preview_font "$FILE" "$WIDTH" "$HEIGHT"; exit
fi

if [[ $mimetype == application/pdf ]]; then
	mutool draw -F txt -i -- "$FILE" 1-10 || pdftotext -l 10 -nopgbrk -q -- "$FILE" - || exiftool "$FILE"
	exit
fi

if [[ $mimetype == application/postscript ]]; then
	pstotext "$FILE" || ps2ascii "$FILE" || exiftool "$FILE"
	exit
fi

if [[ $mimetype == @(text/?(x-)troff|application/x-troff-*) ]]; then
	man "$FILE" | col -b
	exit
fi

if [[ $mimetype == application/vnd.oasis.opendocument.text* ]]; then
	odt2txt "$FILE" || (pandoc -s -t markdown -- "$FILE" | _preview_markdown -)
	exit
fi

if [[ $mimetype == application/epub+zip ]]; then
	epub2txt "$FILE" || exiftool "$FILE"
	exit
fi

if [[ $mimetype == @(application/x-fictionbook+xml|application/vnd.openxmlformats-officedocument.wordprocessingml.document) ]]; then
	pandoc -s -t markdown -- "$FILE" | _preview_markdown -
	exit
fi

if [[ $mimetype == application/x-bittorrent ]]; then
	dumptorrent -v "$FILE" || transmission-show -- "$FILE" || exiftool "$FILE"
	exit
fi

if [[ $mimetype == @(application/zip|application/zlib|application/java-archive|application/vnd.android.package-archive|application/x-zip*) ]]; then
	zip -sf "$FILE" || zipinfo "$FILE" || bsdtar -tf "$FILE"
	exit
fi

if [[ $filename == @(*.tar.@(zst|gz|lz|lzma|lzo|xz|Z)|*.tb2|*.tz2|*.tbz|*.tbz2|*.taz|*.tgz|*.tlz|*.txz|*.tZ|*.taZ|*.tzst) ]] || [[ $mimetype == @(application/x-?(g)tar*|application/*-compressed-tar) ]]; then
	tar -tvf "$FILE" || bsdtar -tf "$FILE"
	exit
fi

if [[ $mimetype == application/zstd ]]; then
	zstd -l "$FILE"; exit
fi

if [[ $mimetype == @(application/x-xz*|application/*-xz-compressed) ]]; then
	xz --list "$FILE" || bsdtar -tf "$FILE"
	exit
fi

if [[ $mimetype == @(application/vnd.rar|application/vnd.comicbook-rar|application/x-rar*) ]]; then
	unrar lt -p- -- "$FILE" || bsdtar -tf "$FILE"
	exit
fi

if [[ $mimetype == application/x-7z-compressed ]]; then
	7z l -p -- "$FILE" || bsdtar -tf "$FILE"
	exit
fi

if [[ $mimetype == @(application/vnd.efi.iso|application/x-*-rom|application/x-compressed-iso|application/x*-iso?(9660)-?(app)image) ]]; then
	isoinfo -f -i "$FILE" || bsdtar -tf "$FILE"
	exit
fi

if [[ $mimetype == application/x-cpio* ]]; then
	cpio -tF "$FILE" || bsdtar -tf "$FILE"
	exit
fi

if [[ $mimetype == application/?(x-)gzip ]]; then
	bsdtar -tf "$FILE" || gzip -l "$FILE"
	exit
fi

if [[ $mimetype == @(application/vnd.ms-cab-compressed|application/x-archive|application/?(x-)bzip*|application/x-lzma|application/x-lzip|application/x-lha|application/x-lzh-compressed|application/x-lhz|application/x-lzop|application/x-lz4|application/x-lrzip) ]]; then
	bsdtar -tf "$FILE"; exit
fi

if [[ $mimetype == application/x-ipynb+json ]]; then
	notedown --from notebook "$FILE" --to markdown | _preview_markdown -
	exit
fi

if [[ $mimetype == text/plain ]] && [[ $filename == *.json?(c|5) ]] || [[ $mimetype == @(application/json*|application/*+json) ]]; then
	jq . "$FILE" | gojq -C . "$FILE" || jaq --color=always . "$FILE" || bat --style=plain --color=always "$FILE" || python3 -m json.tool -- "$FILE"
	exit
fi

if [[ $mimetype == text/plain ]] && [[ $filename == *.@(md|mkd|markdown) ]] || [[ $mimetype == text/markdown ]]; then
	_preview_markdown "$FILE"; exit
fi

if [[ $mimetype == @(text/*|application/javascript|application/xhtml+xml) ]]; then
	bat --style plain --color=always "$FILE"; exit
fi

# Try to get something out of exiftool
# NOTE: exiftool always prints what it can retrieve to stdout, so suppress the message here
metadata="$(exiftool "$FILE")"
if ! (echo "$metadata" | awk -F':' '{print $1}' | grep -q '^Error'); then
	echo "$metadata"
else
	echo '----- File Type Classification -----' && file --dereference --brief -- "$FILE"
fi