optli

#!/bin/bash
# Alternatives: https://github.com/ajslater/picopt
#               https://github.com/thebeansgroup/smush.py
# TODO: implement max file size
# TODO: support gz archives with zopfli

set -u

if [[ $1 == "-h" || $1 == "--help" ]]; then
	echo "Recursively and losslessly optimize images and ZIP archives. Usage: $(basename "$0") [dir] [dir]..."
	echo "!!! WARNING !!!"
	echo "    SVG: optimization necessarily changes the file structure/semantics"
	echo "    ZIP: file signatures will break (e.g. on Android flashable ZIPs)"
	echo "    PNG: dSIG, bKGD and sBIT chunks will be stripped"
	#         see https://github.com/google/zopfli/issues/97#issuecomment-200332768
	echo "    PNG: Some games dislike having their assets messed with"
	exit 1
fi

work() {
	fail() {
		rm -r "$temp" 2>/dev/null
		echo "0 0 error:$2 $1" >&2
		exit 1
	}


	local temp=$(mktemp -u "/tmp/$(basename "$0")_${1##*/}_XXXXXX") || fail "$1" "tempfile"

	[[ -w "$1" ]] || fail "$1" "no-write-permission"
	[[ "$(dirname "$1")/" =~ "fail/" ]] && fail "$1" "possible-test-image"

	case $(file -b --mime-type "$1") in # detect mime type to catch mislabeled file extensions
		image/jpeg)
		case $jpeg in
			mozjpeg)
			mozjpegtran -optimize -copy all -outfile "$temp" "$1" || fail "$1" "conversion"
			;;
			jpegoptim)
			jpegoptim -q -f --strip-none --stdout "$1" > "$temp" || fail "$1" "conversion"
			;;
		esac
		;;

		image/png)
		case $png in
			zopfli)
			zopflipng -m --keepchunks=cHRM,gAMA,iCCP,sRGB,hIST,tRNS,pHYs,sPLT,tIME,iTXt,tEXt,zTXt \
			--always_zopflify "$1" "$temp" >/dev/null
			;;
			optipng)
			optipng -quiet -o7 "$1" -out "$temp" || fail "$1" "conversion"
			;;
		esac
		;;

		image/gif)
		gifsicle -O3 --careful "$1" > "$temp" || fail "$1" "conversion"
		:
		;;

		image/svg+xml|application/xml|text/html|text/plain)
		scour -q -i "$1" -o "$temp" --enable-viewboxing --enable-id-stripping \
		--shorten-ids --indent=none || fail "$1" "conversion"
		# https://github.com/codedread/scour/issues/55 and https://github.com/codedread/scour/issues/56
		sed -i -e 's/ standalone="no"//' -e 's/"/"/g' "$temp" || fail "$1" "fixups"
		;;

		application/zip|application/java-archive)
		7za l -slt "$1" | grep -q "Method = Deflate" || fail "$1" "**store-only**-mode"

		tempdir=$(mktemp -d "/tmp/${1##*/}_XXXXXX") || fail "$1" "tempdir"
		7za x "$1" -o"$tempdir/" >/dev/null || { rm -rf "$tempdir"; fail "$1" "extraction"; }
		shopt -s dotglob
		7za a -tzip -mm=Deflate -mx=9 "$temp" "$tempdir"/* >/dev/null || { rm -rf "$tempdir"; fail "$1" "compression"; }
		rm -rf "$tempdir"
		;;

		*)
		fail "$1" "unknown-filetype"
		;;
	esac

	[[ -s "$temp" ]] || fail "$1" "new-file-not-created"
	oldsize=$(wc -c <"$1"); newsize=$(wc -c <"$temp")
	if [[ $newsize -lt $oldsize ]]; then
		touch -r "$1" "$temp"
		trap '' SIGHUP SIGINT SIGQUIT SIGTERM # don't interrupt while file is being written
		cat "$temp" > "$1" || fail "$1" "writing-new-file" # use cat to preserve owner/perms
		touch -r "$temp" "$1" || fail "$1" "restoring-timestamp"
		trap - SIGHUP SIGINT SIGQUIT SIGTERM

		echo "$oldsize $newsize ✓ $1"
	else
		echo "$oldsize $newsize skipping $1"
	fi
	rm "$temp"
}; export -f work


pattern="-false "

if mozjpegtran -help 2>&1 | grep -q mozjpeg; then
	pattern+="-o -iname *.jpg -o -iname *.jpeg -o -iname *.jpe "; export jpeg="mozjpeg"
elif command -v jpegoptim &>/dev/null; then
	pattern+="-o -iname *.jpg -o -iname *.jpeg -o -iname *.jpe "; export jpeg="jpegoptim"
else
	echo "mozjpegtran/jpegoptim not found, ignoring JPEGs!"
fi
# TODO: test pngwolf
if command -v zopflipng &>/dev/null; then
	pattern+="-o -iname *.png "; export png="zopfli"
elif command -v optipng &>/dev/null; then
	pattern+="-o -iname *.png "; export png="optipng"
else
	echo "zopflipng/optipng not found, ignoring PNGs!"
fi

if command -v gifsicle &>/dev/null; then
	pattern+="-o -iname *.gif "
else
	echo "gifsicle not found, ignoring GIFs!"
fi

if command -v scour &>/dev/null; then
	pattern+="-o -iname *.svg "
else
	echo "scour not found, ignoring SVGs!"
fi
# TODO: use zopfli here once it supports zip
if command -v 7za &>/dev/null; then
	pattern+="-o -iname *.zip"
else
	echo "7za not found, ignoring ZIPs!"
fi

total=0
saved=0

set -f			# disable shell globbing due to unquoted $pattern
shopt -s lastpipe	# run last pipe element in current shell

# make SURE to only run on type f
find "$@" \( $pattern \) -type f -print0 | xargs -r -0 -n1 -P$(getconf _NPROCESSORS_ONLN) bash -c 'work "$@"' _ | while read oldsize newsize status filename; do
	echo "$filename: $oldsize → $newsize, $status"

	total=$(( total + oldsize ))
	saved=$(( saved + (oldsize-newsize) ))
done

if [[ $total == 0 ]]; then percent=0
else percent=$(( 100*$saved/$total ))
fi
printf "\n\n--------------------------------\nTOTAL SAVED (of changed files):\n   %'.fk / %'.fk ($percent%%)\n" $(($saved/1000)) $(($total/1000))