#!/bin/bash

set -e

# ch build <id> ...    build the current package for multiple chroots
# ch build-single <id> [<arguments]
#                      build the current package for one chroot and pass arguments to makechrootpkg
# ch clean             remove all working copies
# ch clean <id>        remove all working copies of this chroot
# ch clean-single <id> remove only this specific working copy
# ch cbuild <id> ...   clean-single then build
# ch install <id> <package files>...
#                      install the package files in the chroot
# ch kill <id>         remove a chroot (including master chroot)
# ch kill all          remove all chroots (including master chroot)
# ch update <id> ...   update a chroot
# ch update            update all chroots
# ch list              lists all existing master chroots
# ch shell <id> [command ...]
#                      spawn a shell/run command in a chroot
# ch shell-bind <id> [command ...]
#                      spawn a shell/run command in a chroot and bind $PWD from the host to /pwd in the chroot
# ch rshell <id> [command ...]
#                      spawn a shell/run command in the master chroot
# ch repack <id> ...   repack (makepkg -R)

# IDs work like this:
# 64    = 64bit extra
# 64t   = 64bit testing
# 64ml  = 64bit multilib
# 64mlt = 64bit multilib testing
#
# 64+foo = 64 extra, but different working copy

# functions for building chroots
CHROOTS="/mnt/chroots/arch"

shopt -s nullglob

umask 022

if [[ ! -d "$CHROOTS" ]]; then
	echo "chroot base directory '$CHROOTS' does not exist or is not readable"
	echo "directory permissions are:"
	namei -l "$CHROOTS"
	return 1
fi

# Always build official packages reproducibly
if [[ ! -v SOURCE_DATE_EPOCH ]]; then
	export SOURCE_DATE_EPOCH=$(date +%s)
fi

__genchroot() {
	sudo btrfs subvolume snapshot "$chrootdir/root" "$copydir"
}

__chrootalias_resolve() {
	chroot=""
	chroot_arch=""
	arg_arch=${1%%+*}
	arg_copy="$USER+$1"
	arg_copy=${arg_copy//+/-}

	case $arg_arch in
		32*)
			chroot_arch=32
			case $arg_arch in
				32) chroot=extra-i686;;
				32t) chroot=testing-i686;;
				32s) chroot=staging-i686;;
			esac
			;;
		64*)
			chroot_arch=64;
			case $arg_arch in
				64) chroot=extra-x86_64;;
				64t) chroot=testing-x86_64;;
				64s) chroot=staging-x86_64;;
				64ml) chroot=multilib-x86_64;;
				64mlt) chroot=multilib-testing-x86_64;;
				64mls) chroot=multilib-staging-x86_64;;
			esac
			;;
		*)
			chroot=$arg_arch
			case $arg_arch in
				*-i686) chroot_arch=32;;
				*-x86_64|multilib*) chroot_arch=64;;
			esac
	esac

	if [[ -z $chroot || -z $chroot_arch ]]; then
		echo "failed to determine chroot for \"$arg_arch\""
		return 1
	fi

	chrootdir="$CHROOTS/$chroot"
	copydir="$chrootdir/$arg_copy"
}

__chrootalias_resolve_create() {
	__chrootalias_resolve "$1"

	local -a packages=(base-devel)
	local chroot_repo=${chroot%-*}

	if [[ $chroot = multilib* ]]; then
		packages+=(multilib-devel)
	fi

	local arch
	case "$chroot_arch" in
		32) arch=i686;;
		64) arch=x86_64;;
	esac

	# create chroot if necessary
	if [[ ! -d "$chrootdir/root" ]]; then
		echo "chroot not found, creating..."
		# from archbuild (devtools)
		sudo mkdir -p "$chrootdir"
		setarch "${arch}" mkarchroot \
			-C "/usr/share/devtools/pacman-${chroot_repo}.conf" \
			-M "/usr/share/devtools/makepkg-${arch}.conf" \
			"$chrootdir/root" \
			"${packages[@]}"
	fi
}

__cleanup_logs() {
	mkdir -p "$1/logs"
	mv "$1/"*.log "$1/"*.log.* "$1/logs/" || return
	gzip -f "$1/logs/"*.log "$1/logs/"*.log.{1,2,3,4,5,6,7,8,9}
}

chkill() {
	if [[ $1 = all ]]; then
		for chrootdir in "$CHROOTS/"*/; do
			chkill "$(basename "$chrootdir")"
		done
		return
	fi

	__chrootalias_resolve "$1" || return
	for dir in "$CHROOTS/$chroot/"*/; do
		sudo btrfs subvolume delete "$dir/var/lib/portables" || true
		sudo btrfs subvolume delete "$dir/var/lib/machines" || true
		sudo btrfs subvolume delete "$dir"
	done
	sudo rm -rf "$CHROOTS/$chroot"
}

chshell() {
	__chrootalias_resolve_create "$1" || return
	[ -d "$copydir" ] || __genchroot
	sudo arch-nspawn "$copydir" "${2:-/bin/bash}" "${@:3}"
}

chbuild() {
	__chrootalias_resolve_create "$1" || return
	linux${chroot_arch} sudo makechrootpkg -l "${copydir##*/}" -r "$chrootdir" -n -- -f "${@:2}" || return
	chshell "$1" pacman --noconfirm -Rcs namcap
	__cleanup_logs "$PWD"
}

chinstall() {
	__chrootalias_resolve_create "$1" || return; shift
	for file in "$@"; do
		files+=(-I "$(readlink -f "$file")")
	done
	cd /var/empty
	linux${chroot_arch} sudo makechrootpkg -l "${copydir##*/}" -r "$chrootdir" "${files[@]}"
}

chclean() {
	__chrootalias_resolve_create "$1" || return
	for copy in $chrootdir/*/; do
		if [[ $copy = */root/ ]]; then
			continue
		fi

		sudo btrfs subvolume delete "$copy/var/lib/portables" || true
		sudo btrfs subvolume delete "$copy/var/lib/machines" || true
		sudo btrfs subvolume delete "$copy"
		sudo rm -f "${copy%/}.lock"
	done
}

chclean-single() {
	__chrootalias_resolve_create "$1" || return
	if [[ -e $copydir ]]; then
		sudo btrfs subvolume delete "$copydir/var/lib/machines" || true
		sudo btrfs subvolume delete "$copydir"
		sudo rm -f "${copydir%/}.lock"
	fi
}

chrshell() {
	__chrootalias_resolve_create "$1" || return
	sudo arch-nspawn "$chrootdir/root" "${2:-/bin/bash}" "${@:3}"
}

chupdate() {
	__chrootalias_resolve_create "$1" || return
	echo ":: Updating $chroot"
	sudo arch-nspawn "$chrootdir/root" pacman -Syu --noconfirm
	echo ":: Cleaning up ..."
	chclean "$1"
}

command=$1; shift
case $command in
	repack)
		for arg; do
			chbuild "$arg" -R
		done
		;;
	cbuild)
		for arg; do
			chclean-single "$arg"
			chbuild "$arg"
		done
		;;
	build)
		for arg; do
			chbuild "$arg"
		done
		;;
	build-single)
		chbuild "$@"
		;;
	update)
		if [[ $# = 0 ]]; then
			for chrootdir in "$CHROOTS/"*/; do
				chupdate "$(basename "$chrootdir")"
			done
		else
			for arg; do
				chupdate "$arg"
			done
		fi
		;;
	clean)
		if [[ $# = 0 ]]; then
			for chrootdir in "$CHROOTS/"*/; do
				chclean "$(basename "$chrootdir")"
			done
		else
			for arg; do
				chclean "$arg"
			done
		fi
		;;
	clean-single)
		for arg; do
			chclean-single "$arg"
		done
		;;
	kill)
		for arg; do
			chkill "$arg"
		done
		;;
	shell) chshell "$@";;
	shell-bind) chshell "$@" --bind-ro="$PWD:/pwd";;
	rshell) chrshell "$@";;
	install) chinstall "$@";;
	list)
		for chrootdir in "$CHROOTS/"*/; do
			basename "$chrootdir"
			for copydir in "$chrootdir/"*/; do
				dirname=$(basename "$copydir")
				if [[ $dirname != "root" ]]; then
					printf "    %s\n" "$dirname"
				fi
			done
		done
		;;
	*) printf "Unknown command %s\n" "$command";;
esac