#!/bin/sh

set -e

usage(){
	printf "Usage: %s [files...]\n" "$0"
	exit 64 # sysexits.h(3) EX_USAGE
}

test -n "$2" \
	|| usage

d="$(mktemp -d || printf '%s/.cbzcat\n' "$HOME/")"
if test -n "$DEBUG"; then
	printf 'Using temporary directory %s\n' "$d"
	set -x
else
	trap 'rm -rf "$d"; trap - EXIT; exit' EXIT INT HUP
fi

parallel \
		test -e {} \
		::: "$@" \
	|| usage

parallel --bar \
	unzip -qqd "$d/"{#} {} \
	::: "$@"

# num is created by the shell (parallel in this case) before the pipeline is
# run, so we have to compensate for it already being in the directory when the
# files are listed
parallel \
	rm -f {}/*.xml \; \
	ls {} \
		\| grep -v \
			-e '^num$' \
		\| wc -l \
		\>{}/num \; \
	printf '0\\n' \
		'>>'{}/prevs \; \
	::: "$d"/*

parallel \
	test {1/} -lt {2/} \
		'&&' dd \
			'<'{1}/num \
			'>>'{2}/prevs \
			'2>'/dev/null \
		'||' true \
	::: "$d"/* \
	::: "$d"/*

parallel \
	\<{}/prevs \
		sed 's/\\$/ + /' \
		\| tr -d '\n' \
		\| sed 's/ + \\$//' \
		\| bc \
		\>{}/sum \
	::: "$d"/*

false

parallel \
	ls {}/../ \; \
	parallel -I [] --arg-sep :::: \
			test [] -lt {} \
				'&&' '<'[]/num xargs \
					printf '%s + ' \
			:::: {}/../* \
		\| sed 's| + $||' \
		\| bc \
		\>{}/prevs \
		::: "$d"/*



mkdir "$d"/0

false

parallel --dry-run sh -c "\
for dir in "

zip -Z deflate out.cbz "$d"/0/*

rm -r "$d"