image-compact

#!/bin/bash

sz=1920x1440

usage() {
	local bin=$(basename $0)
	[[ $1 -eq 0 ]] || exec 1>&2
	echo "Usage: [SZ=$sz] $bin /path/to/some/image.jpg ..."
	echo
	echo "SZ env-var can be a size for square to fit image into, or WxH spec"
	echo "  for rectangle with max width/height. Scaling is always proportional."
	echo "Uses imagemagick with jpg destination and quality=80, and jpegoptim on that."
	exit ${1:-1}; }
[[ "$1" = -h || "$1" = --help ]] && usage 0
[[ "$#" -ge 1 ]] || usage 1
set -eo pipefail

du_hs() {
	local du dup
	read -ra du dup < <(du -hs "$1" || kill -INT $$)
	printf '%s' "$du"; }

[[ -z "$SZ" ]] || sz=$SZ
[[ "$sz" == *x* ]] || sz="${sz}x${sz}"

for p in "$@"; do
	[[ -e "$p" ]] || { echo >&2 "ERROR: nx input file - '$p'"; exit 1; }
	[[ ! -e "$p".fix.jpg ]] || {
		echo >&2 "ERROR: temp-file from earlier bug - $p.fix.jpg"; exit 1; }

	du1=$(du_hs "$p")
	magick "$p" -resize "${sz}>" -quality 80 "$p".fix.jpg
	jpegoptim -q --strip-all --all-normal --force "$p".fix.jpg
	touch -m --reference="$p" "$p".fix.jpg
	mv "$p".fix.jpg "$p"

	p0=$p ext="${p##*.}"
	[[ "$ext" = jpg ]] && ext= || {
		if [[ ${#ext} -gt 4 ]]
		then echo >&2 "WARN: no proper filename.ext on [ $p ]"; ext=" :: $ext ???"
		else p=${p%.*}.jpg; mv "$p0" "$p"; ext=" :: $ext -> jpg"; fi; }

	du2=$(du_hs "$p")
	echo "$p0 :: $du1 -> $du2$ext"
done