#!/bin/sh

set -e

# DEP17 M18: Duplicate diversion in aliased location /bin.

die() {
	printf '%s, cannot proceed\n' "$*" 1>&2
	exit 1
}

case "${1}" in
	install)
		# Situations considered:
		#  * bookworm or earlier gzip is fully installed.
		#    -> No diversions, /bin/${FILE}
		#  * trixie or later gzip is unpacked.
		#    -> No diversions, /usr/bin/${FILE}
		#  * trixie or later gzip has been unpacked while bookworm's
		#    zutils was installed, but zutils has since been removed.
		#    -> /usr/bin/FILE -> /usr/bin/FILE.usr-is-merged
		#  * trixie or later gzip is fully installed.
		#    -> No diversions, /usr/bin/${FILE}
		#
		# We cannot run between gzip.preinst and gzip unpack.
		GZIP_VERSION=$(dpkg-query -f '${Version}' -W gzip)
		GZIP_PREFIX=/usr
		dpkg --compare-versions "$GZIP_VERSION" lt 1.12-1.1~ && GZIP_PREFIX=
		for FILE in zcat zcmp zdiff zegrep zfgrep zgrep
		do
			TRUENAME=$(dpkg-divert --truename "/usr/bin/${FILE}")
			if [ "${TRUENAME}" = "/usr/bin/${FILE}.usr-is-merged" ]
			then
				dpkg-divert --package zutils --quiet --remove --no-rename --divert "${TRUENAME}" "/usr/bin/${FILE}"
			elif [ "${TRUENAME}" != "/usr/bin/${FILE}" ]
			then
				die "unexpected diversion of /usr/bin/${FILE} to ${TRUENAME}"
			fi
			# We cannot --rename, because it'll rename any existing
			# file without checking whether the file is owned or
			# not. Correctly compute the required rename depending
			# on the gzip version.
			dpkg-divert --package zutils --quiet --add --no-rename --divert "/usr/bin/${FILE}.gzip" "/usr/bin/${FILE}"
			dpkg-divert --package zutils --quiet --add --no-rename --divert "/bin/${FILE}.gzip.usr-is-merged" "/bin/${FILE}"
			mv "${DPKG_ROOT:-}${TRUENAME}" "${DPKG_ROOT:-}${GZIP_PREFIX}/bin/${FILE}.gzip${GZIP_PREFIX:+.usr-is-merged}"
			dpkg-divert --package zutils --quiet --add --rename --divert /usr/share/man/man1/${FILE}.gzip.1.gz /usr/share/man/man1/${FILE}.1.gz
		done
		;;

	upgrade)
		for FILE in zcat zcmp zdiff zegrep zfgrep zgrep
		do
			TRUENAME=$(dpkg-divert --truename "/usr/bin/${FILE}")

			if [ "${TRUENAME}" = "/usr/bin/${FILE}.usr-is-merged" ]
			then

				# This branch should be dead code. The
				# diversion indicates that trixie's gzip has
				# been unpacked, but trixie's gzip also
				# conflicts with zutils (<< trixie), so either
				# we're not installing or we are upgrading from
				# trixie.
				if ! [ -e "${DPKG_ROOT}${TRUENAME}" ]
				then
					die "diverted file ${TRUENAME} does not exist"
				fi
				dpkg-divert --package zutils --quiet --remove --no-rename --divert "/usr/bin/${FILE}.usr-is-merged" "/usr/bin/${FILE}"
				dpkg-divert --package zutils --quiet --remove --no-rename "/bin/${FILE}"
				dpkg-divert --package zutils --quiet --add --no-rename --divert "/usr/bin/${FILE}.gzip" "/usr/bin/${FILE}"
				dpkg-divert --package zutils --quiet --add --no-rename --divert "/bin/${FILE}.gzip.usr-is-merged" "/bin/${FILE}"
				mv "${DPKG_ROOT}${TRUENAME}" "${DPKG_ROOT}/usr/bin/${FILE}.gzip"
			elif [ "${TRUENAME}" = "/usr/bin/${FILE}" ]
			then
				dpkg-divert --package zutils --quiet --add --no-rename --divert "/usr/bin/${FILE}.gzip" "/usr/bin/${FILE}"

				TRUENAME=$(dpkg-divert --truename "/bin/${FILE}")

				if [ "${TRUENAME}" != "/bin/${FILE}.gzip.usr-is-merged" ]
				then
					dpkg-divert --package zutils --quiet --remove --no-rename "/bin/${FILE}"
					dpkg-divert --package zutils --quiet --add --no-rename --divert "/bin/${FILE}.gzip.usr-is-merged" "/bin/${FILE}"
					if [ -e "${DPKG_ROOT}${TRUENAME}" ] || [ -h "${DPKG_ROOT}${TRUENAME}" ]
					then
						mv "${DPKG_ROOT}${TRUENAME}" "${DPKG_ROOT}/bin/${FILE}.gzip.usr-is-merged"
					fi
				fi
			elif [ "${TRUENAME}" != "/usr/bin/${FILE}.gzip" ]
			then
				die "unexpected diversion of /usr/bin/${FILE} to ${TRUENAME}"
			fi
		done
		;;

	abort-upgrade)

		;;

	*)
		echo "preinst called with unknown argument \`${1}'" >&2
		exit 1
		;;
esac

# Automatically added by dh_installdeb/13.24.2
dpkg-maintscript-helper rm_conffile /etc/zutilsrc 1.12-3\~ -- "$@"
# End automatically added section


exit 0