#!/bin/bash -euE
# librechroot

# Copyright 2010 Nicolás Reynolds
# Copyright 2011 Joshua Haase
# Copyright 2012 Luke Shumaker
#
# This file is part of Parabola.
#
# Parabola is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Parabola is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Parabola. If not, see <http://www.gnu.org/licenses/>.

. /usr/share/libretools/conf.sh
load_conf_libretools_chroot

. "$(which libremessages)"

# This file (librechroot) is GPLv3+, but I would like to use some code
# modified from devtools' "makechrootpkg", which is GPLv2.
. "$(dirname "$0")/librechroot.gpl2"
# This gives us the functions:
#  - sync

cleanup=(':');
cleanup() {
	for cmd in "${cleanup[@]}"; do
		$cmd
	done
}

cmd=${0##*/}
usage() {
	echo "Usage: $cmd [OPTIONS] "
	echo 'Interacts with a chroot.'
	echo ''
	echo 'This command will make the following configuration changes in'
	echo 'the chroot:'
	echo "  - overwrite \`/etc/libretools.d/chroot.conf'"
	echo "  - overwrite \`/etc/pacman.d/mirrorlist'"
	echo "  - set \`CacheDir' in \`/etc/pacman.conf'"
	echo ''
	echo 'Options:'
	echo ' Settings:'
	echo "  -n <CHROOT>   Use this chroot instead of \`$CHROOT'"
	echo "  -l <COPY>     Use this chroot copy instead \`$CHROOTCOPY'"
	echo '  -N            Disable networking in the chroot'
	echo ''
	echo ' Modes: (the last mode given will be used)'
	echo '  -C            Clean /repo in the chroot'
	echo '  -c            Clean the packages installed in the chroot'
	echo '  -I <FILE>     Install the package FILE into the chroot'
	echo '  -i <PKG>      Install the package PKG from repos into the chroot'
	echo '  -m            Make sure the chroot exists; do nothing else'
	echo '  -r <CMD>      Run CMD in the chroot'
	echo "  -s            Sync the copy with the \`root' copy"
	echo '  -u            Update the chroot'
	echo '  -h            Show this message'
}

main() {
	CHROOTCOPY=$LIBREUSER
	[[ $CHROOTCOPY != root ]] || CHROOTCOPY=copy

	local mode=enter
	local archroot_args=(-f)
	local ARG=''
	while getopts 'n:l:NCcI:i:mr:suh' arg; do
		case $arg in
			n) CHROOT=$OPTARG;;
			l) CHROOTCOPY=$OPTARG;;
			N) archroot_args+=(-N);;

			C) mode=clean_repo;;
			c) mode=clean_pacman;;
			I) mode=install_file; ARG=$OPTARG;;
			i) mode=install_pkg; ARG=$OPTARG;;
			m) mode=noop;;
			r) mode=run; ARG=$OPTARG;;
			s) mode=sync;;
			u) mode=update;;

			h) usage; exit 0;;
			*) usage; exit 1;;
		esac
	done
	shift $(($OPTIND - 1))
	if [[ $# > 0 ]]; then
		usage
		exit 1
	fi

	# not local
	rootdir="${CHROOTDIR}/${CHROOT}/root"
	copydir="${CHROOTDIR}/${CHROOT}/${CHROOTCOPY}"

	########################################################################

	if (( EUID )); then
		error "This script must be run as root."
		exit 1
	fi

	# Keep this lock as long as we are running
	# Note that '9' is the same FD number as in (mk)archroot
	lock_open_write 9 "$copydir" \
		"Waiting for existing lock on \`$copydir' to be released"

	if [[ ! -d $rootdir ]]; then
		libremkchroot "$CHROOT"
	fi

	if [[ ! -d $copydir ]] && [[ $mode != sync ]]; then
		sync
	fi

	mkdir -p $copydir/etc/libretools.d
	{
		if [[ -n ${CHROOTEXTRAPKG[@]:-} ]]; then
			printf 'CHROOTEXTRAPKG=('
			printf "'%s' " "${CHROOTEXTRAPKG[@]}"
			printf ')\n'
		else
			printf 'CHROOTEXTRAPKG=()\n'
		fi
	} > $copydir/etc/libretools.d/chroot.conf

	########################################################################

	trap cleanup EXIT
	case "$mode" in
		clean_repo)
			rm -rf "${copydir}/repo/*"
			bsdtar -czf "${copydir}/repo/repo.db.tar.gz" -T /dev/null
			ln -s "repo.db.tar.gz" "${copydir}/repo/repo.db"
			;;
		clean_pacman)
			cleanup+=("rm -f $copydir/clean $copydir/chrootexec")
			cp -a "$(which chcleanup)"  "${copydir}/clean"
			echo '#!/bin/bash'        > "${copydir}/chrootexec"
			echo 'mkdir /build'      >> "${copydir}/chrootexec"
			echo 'cd /build; /clean' >> "${copydir}/chrootexec"
			chmod 755 "${copydir}/chrootexec"
			archroot "${archroot_args[@]}" "${copydir}" -r /chrootexec
			;;
		install_file)
			cleanup+=("rm $copydir/${ARG##*/}")
			cp "$ARG" "$copydir/${ARG##*/}"
			archroot "${archroot_args[@]}" "${copydir}" -r "pacman -U /${ARG##*/} --noconfirm"
			;;
		install_pkg) archroot "${archroot_args[@]}" "${copydir}" -i $ARG ;;
		noop) :;;
		run)         archroot "${archroot_args[@]}" "${copydir}" -r "$ARG" ;;
		sync) sync;;
		update)      archroot "${archroot_args[@]}" "${copydir}" -u ;;
		enter)       archroot "${archroot_args[@]}" "${copydir}" -r bash ;;
	esac
}

main "$@"