#!/bin/sh

PREFIX=@PREFIX@
: ${LIBDIR=$PREFIX/lib}
. "$LIBDIR/libalpine.sh"

zroot="$ROOT"/usr/share/zoneinfo

usage() {
	cat <<-__EOF__
		usage: setup-timezone [-h] [-k|-i] [TIMEZONE]

		Sets the timezone for the system.

		options:
		 -h  Show this help
		 -i  Install tzdata and symlink instead of making a copy
		 -k  Keep previous copies of tzdata

		TIMEZONE is relative $zroot.

		If TIMEZONE is not specified user will be prompted.
	__EOF__
	exit $1
}

show_tz_list() {
	local i z= list=
	local path="$zroot/$1"
	[ -d "$path" ] || return 1

	for i in $(find $path/ -maxdepth 1); do
		case $i in
		*.tab|*/) continue;;
		esac
		if [ -d "$i" ]; then
			z="$z ${i##*/}/"
		else
			z="$z ${i##*/}"
		fi
	done
	( cd $path && ls --color=never -Cd $z )
}

setup_tz() {
	local zonepath="$1"
	mkdir -p "${ROOT}"etc/zoneinfo
	if ! $INSTALL_TZDATA; then
		local zone="${zonepath#*/zoneinfo/}"
		local zdir="${zonepath%/*}"/
		zdir="${zdir#*/zoneinfo/}"
		if ! $KEEP_TZDATA; then
			rm -r "${ROOT}"/etc/zoneinfo
		fi
		mkdir -p "${ROOT}"etc/zoneinfo/$zdir
		cp "$zonepath" "${ROOT}"etc/zoneinfo/$zdir/
		zonepath=/etc/zoneinfo/$zone
	fi
	rm -f "${ROOT}"etc/localtime
	ln -s "$zonepath" "${ROOT}"etc/localtime
}

INSTALL_TZDATA=false
KEEP_TZDATA=false
while getopts "hikz:" opt; do
	case $opt in
		h) usage 0;;
		i) INSTALL_TZDATA=true;;
		k) KEEP_TZDATA=true;;
		z) ZONE="$OPTARG";;  # backwards compat
		'?') usage "1" >&2;;
	esac
done
shift $(( $OPTIND - 1))

if [ -z "$ZONE" ]; then
	ZONE="$1"
fi

if [ "$ZONE" = "none" ]; then
	exit 0
fi

if $INSTALL_TZDATA; then
	pkg=tzdata
	apkdel=
else
	pkg="--force --virtual .setup-timezone tzdata"
	apkdel=".setup-timezone"
fi

apk add --no-progress --quiet $pkg || die "Failed to install tzdata package"

if [ -n "$apkdel" ]; then
	trap "apk del --no-progress --quiet $apkdel" EXIT HUP INT TERM
fi

if [ -L "${ROOT}"etc/zoneinfo/localtime ]; then
	default_timezone=$(readlink "${ROOT}"etc/zoneinfo/localtime)
	default_timezone=${timezone#*/zoneinfo/}
else
	default_timezone=UTC
fi

if [ -n "$ZONE" ]; then
	[ -f "$zroot/$ZONE" ] || die "'$ZONE' is not a valid timezone on this system"
	setup_tz "$zroot"/"$ZONE"
else
	while true; do
		ask "Which timezone are you in? ('?' for list)" "$default_timezone"
		timezone="$resp"
		case "$timezone" in
		"") continue;;
		"?") show_tz_list; continue;;
		esac

		while [ -d "$zroot/$timezone" ]; do
			ask "What sub-timezone of '$timezone' are you in? ('?' for list)"
			zone="$resp"
			case "$zone" in
			"?") show_tz_list "$timezone"; continue;;
			esac
			default_timezone="$timezone"
			timezone="$timezone/$zone"
		done

		if [ -f "$zroot/$timezone" ]; then
			setup_tz "$zroot/$timezone"
			break
		fi
		echo "'$timezone' is not a valid timezone on this system"
	done
fi