#!/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/>.

. /etc/libretools.conf

##
# This function is almost verbatim from makechrootpkg
##
sync() {
	if [[ $CHROOTCOPY = root ]]; then
		error "Cannot sync the root copy with itself"
		exit 1
	fi

	lock_open_read  8 "$rootdir" "Locking clean chroot"

	stat_busy 'Creating clean working copy'
	local use_rsync=false
	if type -P btrfs >/dev/null; then
		[[ -d $copydir ]] && btrfs subvolume delete "$copydir" &>/dev/null
		btrfs subvolume snapshot "$chrootdir/root" "$copydir" &>/dev/null || use_rsync=true
	else
		use_rsync=true
	fi

	if $use_rsync; then
		mkdir -p "$copydir"
		rsync -a --delete -q -W -x "$CHROOTDIR/$CHROOT/root/" "$copydir"
	fi
	stat_done

	lock_close 8
}

usage() {
	echo "Usage: $cmd [OPTIONS] [CHROOT] "
	echo 'Interacts with a chroot.'
	echo ''
	echo "The default CHROOT is \`${CHROOT}'."
	echo ''
	echo 'Options:'
	echo ' Settings:'
	echo ' -l <COPY>       Use this as the chroot copy instead of basing it'
	echo '                 on the username'
	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 ' -n              No-op, just make sure that the chroot exists'
	echo ' -r <CMD>        Run CMD in the chroot'
	echo " -s              Sync the copy with the 'root' copy"
	echo ' -u              Update the chroot'
	echo ' -h              Print this message'
}

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

	local mode=enter
	local archroot_args=()
	local ARG=''
	while getopts 'l:NCcI:i:nrsuh' arg; do
		case $arg in
			l) CHROOTCOPY=$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;;
			n) 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))
	case $# in
		0) :;;
		1) CHROOT="$1";;
		*) usage; exit 1;;
	esac

	# 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 "$copydir" "Locking chroot copy '$copy'"

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

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

	case "$mode" in
		clean_repo)
			msg "Cleaning local pacman repository"
			rm -rf "${copydir}/repo"
			mkdir "${copydir}/repo"
			bsdtar -czf "${copydir}/repo/repo.db.tar.gz" -T /dev/null
			ln -s "repo.db.tar.gz" "${copydir}/repo/repo.db"
			;;
		clean_pacman)
			msg "Intelligently cleaning packages"
			cp -a "$(dirname $0)/chcleanup"   "${copydir}/clean"
			mkdir -p "$copydir/build"
			archroot "${archroot_args[@]}" "${copydir}" -r "cd /build; /clean"
			;;
		install_file)
			msg "Installing package file: $ARG"
			cp "$ARG" "$copydir/${ARG##*/}"
			archroot "${archroot_args[@]}" "$copydir" -r "pacman -U /${ARG##*/} --noconfirm"
			rm "$copydir/${ARG##*/}"
			;;
		install_pkg)
			msg "Installing package(s): $ARG"
			archroot "${archroot_args[@]}" "$copydir" -i $ARG
			;;
		noop) :;;
		run)
			msg "Running command"
			archroot "${archroot_args[@]}" "${copydir}" -r "$ARG"
			;;
		sync) sync;;
		update)
			msg "Updating chroot"
			archroot "${archroot_args[@]}" "${copydir}" -u
			;;
		enter)
			msg "Entering chroot"
			archroot "${archroot_args[@]}" "${copydir}" -r bash
			;;
	esac
}

main "$@"