## Some default values of important variables

## Settings
GPG_RECIPIENT="robin.oburka@nic.cz"

## Style
TIME_FMT="Time:\t%E"

## Internal variables
NAME=""
DST_COMMAND=""
#GENERATE="sudo"
GENERATE=""
COMMAND=""
PLACES=""
EXCLUDE=""
MIDDLE=""
STORE=""

## Pipeline variables
PID_GENERATE=""
PID_MIDDLE=""
PID_STORE=""
FIFO_GEN=""
FIFO_STORE=""

test_input() {
	[ -z "$NAME" ] && error "Specify backup name"
	[ -z "$COMMAND" -a -z "$PLACES" ] && error "Specify backup subject"
	[ -n "$COMMAND" -a -n "$PLACES" ] && error "Do not specify two types of backup at once"
}

name() {
	NAME="$1"
}

generate() {
	GENERATE="$1"
}

cmd() {
	COMMAND="$1"
}

places() {
	PLACES="$1"
	[ "$#" -gt 1 ] && error "Specify places as string"

	#STR=""
	#for PLACE in "$@"; do
	#	STR="$STR "$PLACE""
	#done
	#PLACES="$STR"
}

exclude() {
	STR=""
	for EXC in "$@"; do
		STR="$STR --exclude=$EXC"
	done
	EXCLUDE="$STR"
}

middle() {
	MIDDLE="$1"
}

store() {
	STORE="$1"
}

error() {
	echo "ERROR: $1" >&2
	exit 1
}

die() {
	if [ -n "$1" ]; then
		echo "DIE: $1" >&2
	fi
	kill -6 "$$"
}

compute_variables() {
	UTS="$(date +"%s")"
	TS="$(date +"%Y-%m-%d_%H-%M-%S")"
	FILENAME="backup_"$NAME"_"$TS".tar"
	FILENAME_ENC="$FILENAME".gpg
	FIFO_GEN="/tmp/backuper_pipe_gen_$$_$UTS"
	FIFO_STORE="/tmp/backuper_pipe_str_$$_$UTS"
}

title() {
	TXT="$1"
	printf "\n%s\n==========================================\n" "$TXT"
}

get_size() {
	FILE="$1"
	du -h "$FILE" | awk '{ print $1 }'
}

prepare() {

	#mkdir -p "$DST"
	#touch "$DST"/"$FILENAME"
	##chown root:root "$DST"/"$FILENAME"
	#chmod 600 "$DST"/"$FILENAME"
	echo "prepare $$"
	trap 'error_handler' EXIT INT QUIT TERM ABRT HUP ILL TRAP BUS FPE SEGV
	mkfifo "$FIFO_GEN"
	mkfifo "$FIFO_STORE"
}

error_handler() {
	cleanup
	exit 42
}

cleanup() {
	echo "Cleaning up... ($$)" >&2

	trap - EXIT INT QUIT TERM HUP ILL TRAP BUS FPE SEGV

	[ -n "$PID_GENERATE" ] && if ps --ppid $$ | grep -q "$PID_GENERATE"; then
		echo "Killing "$PID_GENERATE""
		kill "$PID_GENERATE"
	fi
	[ -n "$PID_MIDDLE" ] && if ps --ppid $$ | grep -q "$PID_MIDDLE"; then
		echo "Killing "$PID_MIDDLE""
		kill "$PID_MIDDLE"
	fi
	[ -n "$PID_STORE" ] && if ps --ppid $$ | grep -q "$PID_STORE"; then
		echo "Killing "$PID_STORE""
		kill "$PID_STORE"
	fi

	rm -f "$FIFO_GEN"
	rm -f "$FIFO_STORE"

}

start_store() {
	$STORE < "$FIFO_STORE"
}

start_middle() {
	$MIDDLE < "$FIFO_GEN" > "$FIFO_STORE"
}

start_command() {
	if [ -n "$COMMAND" ]; then
		echo "$COMMAND" | $GENERATE sh -s > "$FIFO_GEN"
	else
		## Exclude keep without quotes
		/usr/bin/time -f "$TIME_FMT" $GENERATE tar c --preserve-permissions $EXCLUDE "$PLACES" > "$FIFO_GEN"
	fi


#	if [ -z "$GENERATE" ]; then
#		$COMMAND > "FIFO_GEN"
#	else
#		echo $COMMAND | $GENERATE sh -s
#	fi
}

start_pipeline() {
	start_store || die &
	PID_STORE=$!

	start_middle || die &
	PID_MIDDLE=$!

	start_command || die &
	PID_COMMAND=$!

#	if ! wait "$PID_COMMAND"; then
#		die "Backup command failed"
#	fi
#	echo "Command done" >&2
#
#	if ! wait "$PID_STORE"; then
#		die "Store command failed"
#	fi
#	echo "Store done" >&2
#
#	if ! wait "$PID_MIDDLE"; then
#		die "Middle command failed"
#	fi
#	echo "Middle done" >&2
wait "$PID_STORE" "$PID_MIDDLE" "$PID_COMMAND"
}

#backup_cmd() {
#	/usr/bin/time -f "$TIME_FMT" $COMMAND
#	[ "$?" != 0 ] && die "Generator command exited with error"
#}
#
#create_backup() {
#	title "Create"
#
#	if [ -n "$PLACES" ]; then
#		backup_tar | cat > "$DST"/"$FILENAME"
#	elif [ -n "$COMMAND" ]; then
#		echo "Generating with command: $COMMAND"
#		backup_cmd | cat > "$DST"/"$FILENAME"
#	else
#		error "There is no generating command"
#	fi
#
#	printf "Backup:\t%s (%s)\n\n" "$FILENAME" "$(get_size "$DST"/"$FILENAME")"
#}
#
#enc() {
#	title "Encrypt"
#	/usr/bin/time -f "$TIME_FMT" gpg --compress-algo zlib --recipient "$GPG_RECIPIENT" -e "$DST"/"$FILENAME"
#	[ "$?" != 0 ] && die "Encription failed"
#	rm "$DST"/"$FILENAME"
#	printf "Encrypted backup:\t%s (%s)\n\n" "$FILENAME_ENC" "$(get_size "$DST"/"$FILENAME_ENC")"
#}
#
#run() {
#	title "Run command"
#	echo "$@"
#	CMD="sh -c \"$@\""
#	echo $@ | $GENERATE sh -s
#	printf "\n"
#}

backup() {
	test_input
	compute_variables
	prepare
	start_pipeline
	#kill $$
	cleanup
	#create_backup
	#secure
	#enc
	#send
}