#!/bin/bash

set -e

OLDDIR=`pwd`

BASE_DIR=$(cd `dirname "$0"`; pwd)

cd "$OLDDIR"

INSTANCE_ID=`uuidgen`

INSTANCE_KEY=

PRIVILEGED=

COMMANDARCH=

IMAGE_MOUNT_DIR=

COMMAND_ERROR=

PREFIX="$CHROOTER_PREFIX"

if [ -z "$PREFIX" ]; then

	PREFIX="/tmp"

fi

FULLPREFIX="$PREFIX/chrooter"

trap 'raise_error terminated' SIGINT

raise_error() {

	echo "Error: $1"

	rm -f "/$FULLPREFIX-$INSTANCE_ID.chroot.sh"

	image_unmount

	exit 1

}

check_runned() {

	if [ ! -z "$INSTANCE_KEY" ]; then

		if [ "0" != `mount | grep -c "$FULLPREFIX-$INSTANCE_KEY"` ]; then

			raise_error "instance with key '$INSTANCE_KEY', is already running"

		fi

	fi

}

image_mount_add() {

	echo "Mount: $1 -> $2"

	sudo mkdir -p "$IMAGE_MOUNT_DIR/root$2"

	sudo mount --bind "$1" "$IMAGE_MOUNT_DIR/root$2"

	echo "umount -f \"$IMAGE_MOUNT_DIR/root$2\" || umount -l \"$IMAGE_MOUNT_DIR/root$2\"" >> "$IMAGE_MOUNT_DIR/umount.sh"

}

image_mount() {

	echo "Mount image: $1"

	if [ ! -z "$IMAGE_MOUNT_DIR" ]; then

		echo "Image already mounted"

		return 1

	fi

	if [ -z "$1" ]; then

		echo "Image name was not set"

		return 1

	fi

	local IMAGE_NAME="$(echo $1 | tr "/:" "_")"

	local IMAGE_FILE="$BASE_DIR/image/$IMAGE_NAME.iso"

	echo "Prepare image: $1"

	IMAGE_MOUNT_DIR="/$FULLPREFIX-$INSTANCE_KEY-$INSTANCE_ID"

	mkdir -p "$IMAGE_MOUNT_DIR/iso"

	mkdir -p "$IMAGE_MOUNT_DIR/work"

	mkdir -p "$IMAGE_MOUNT_DIR/root"

	echo "Add -.chroot.sh file"

	sudo mv "/$FULLPREFIX-$INSTANCE_ID.chroot.sh" "$IMAGE_MOUNT_DIR/work/chroot-$INSTANCE_ID.sh"

	sudo chmod a+x "$IMAGE_MOUNT_DIR/work/chroot-$INSTANCE_ID.sh"

	echo "Mount root"

	sudo mount -r "$IMAGE_FILE" "$IMAGE_MOUNT_DIR/iso"

	sudo mount -wt aufs -o br=$IMAGE_MOUNT_DIR/work:$IMAGE_MOUNT_DIR/iso -o udba=none none $IMAGE_MOUNT_DIR/root/

	set -- "${@:2}"

	echo "Mount subs: $@"

	echo "#!/bin/bash" > "$IMAGE_MOUNT_DIR/umount.sh"

	chmod a+x "$IMAGE_MOUNT_DIR/umount.sh"

	if [ ! -z "$PRIVILEGED" ]; then

		echo "Mount /proc and /dev for priveleged feature"

		image_mount_add /proc /proc

		image_mount_add /dev /dev

	fi

	for ARG in $@; do

		SRC="$(echo "$ARG" | cut -d':' -f 1)"

		DEST="$(echo "$ARG" | cut -d':' -f 2-)"

		image_mount_add $SRC $DEST

	done

	echo "Add /etc/resolv.conf"

	sudo cp /etc/resolv.conf $IMAGE_MOUNT_DIR/root/

	sudo mkdir -p $IMAGE_MOUNT_DIR/root/etc && sudo cp /etc/resolv.conf $IMAGE_MOUNT_DIR/root/etc/

}

image_unmount() {

	echo "Unmount image"

	if [ -z "$IMAGE_MOUNT_DIR" ]; then

		echo "Image not mounted"

		return 1

	fi

	echo "Unmount subs"

	sudo "$IMAGE_MOUNT_DIR/umount.sh"

	sudo rm -f "$IMAGE_MOUNT_DIR/umount.sh"

	echo "Remove chroot-.sh file"

	sudo rm -f "$IMAGE_MOUNT_DIR/root/chroot-$INSTANCE_ID.sh"

	if [ ! -z $1 ]; then

		echo "Save image: $1"

		local IMAGE_NAME="$(echo $1 | tr "/:" "_")"

		local IMAGE_FILE="$BASE_DIR/image/$IMAGE_NAME.iso"

		local IMAGE_DIR=`dirname "$IMAGE_FILE"`

		mkdir -p "$IMAGE_DIR"

		sudo rm -f "$IMAGE_FILE"

		sudo genisoimage -quiet -R -o "$IMAGE_FILE" "$IMAGE_MOUNT_DIR/root"

	fi

	sudo umount -R -f "$IMAGE_MOUNT_DIR/root" || umount -R -l "$IMAGE_MOUNT_DIR/root"

	sudo umount -f "$IMAGE_MOUNT_DIR/iso"  || umount -l "$IMAGE_MOUNT_DIR/iso"

	echo "Remove mount dirs"

	sudo rm -rf --one-file-system "$IMAGE_MOUNT_DIR"

	IMAGE_MOUNT_DIR=

}

image_command() {

	echo "Run command: $@"

	if [ -z "$IMAGE_MOUNT_DIR" ]; then

		echo "Image not mounted"

		return 1

	fi

	local SETARCH=

	if [ ! -z "$COMMANDARCH" ]; then

		SETARCH=setarch

	fi

	if ! env -i /usr/bin/sudo -i $SETARCH $COMMANDARCH chroot "$IMAGE_MOUNT_DIR/root" "/chroot-$INSTANCE_ID.sh" $@; then

		COMMAND_ERROR=1

		echo "Command returned with error"

	fi

}

image_copy() {

	echo "Copy into image: $1 $2"

	if ! cp "$1" "$IMAGE_MOUNT_DIR/root/$2"; then

		echo "Cannot copy \"$1\" -> \"$IMAGE_MOUNT_DIR/root/$2\""

		return 1

	fi

}

chroot_file_begin() {

	echo "#!/bin/sh" > "/$FULLPREFIX-$INSTANCE_ID.chroot.sh"

	echo "" >> "/$FULLPREFIX-$INSTANCE_ID.chroot.sh"

}

chroot_file_env() {

	echo "Set env: $1=\"$2\""

	echo "export $1=\"$2\"" >> "/$FULLPREFIX-$INSTANCE_ID.chroot.sh"

}

chroot_file_end() {

	echo "\$@" >> "/$FULLPREFIX-$INSTANCE_ID.chroot.sh"

}

import() {

	echo "Import $2"

	if [ ! "$1" = "-" ]; then

		echo "Unknown commandline argument $1"

	fi

	if [ -z "$2" ]; then

		echo "Image name was not set"

		return 1

	fi

	local IMAGE_NAME="$(echo $2 | tr "/:" "_")"

	INSTANCE_KEY = IMAGE_NAME

	check_runned

	local IMAGE_FILE="$BASE_DIR/image/$IMAGE_NAME.iso"

	local IMAGE_DIR=`dirname "$IMAGE_FILE"`

	mkdir -p "$IMAGE_DIR"

	cat "/dev/stdin" > $IMAGE_FILE

}

build() {

	echo "Build"

	local IMAGE_NAME=

	local WORK_DIR=

	chroot_file_begin

	local MODE=

	for ARG in $@; do

		if [ -z "$WORK_DIR" ]; then

			if [ "$MODE" = "-t" ]; then

				IMAGE_NAME="$ARG"

				echo "Set image name: $IMAGE_NAME"

				MODE=

				continue

			fi

		fi

		if [ ! -z "$MODE" ]; then

			echo "Unknown commandline argument: $MODE"

		fi

		MODE=

		if [ ! -z "$WORK_DIR" ]; then

			echo "Unknown commandline argument: $ARG"

		elif [ "$ARG" = "--privileged=true" ]; then

			PRIVILEGED=1

			echo "Set privileged: true"

		elif [ "${ARG:0:1}" = "-" ]; then

			SUBMODE="$(echo "$ARG" | cut -d'=' -f 1)"

			SUBVALUE="$(echo "$ARG" | cut -d'=' -f 2-)"

			if [ "$SUBMODE" = "--build-arg" ]; then

				ENVKEY="$(echo "$SUBVALUE" | cut -d'=' -f 1)"

				ENVVALUE="$(echo "$SUBVALUE" | cut -d'=' -f 2-)"

				chroot_file_env "$ENVKEY" "$ENVVALUE"

				continue

			elif [ "$SUBMODE" = "--buildarch" ]; then

				COMMANDARCH="$SUBVALUE"

				continue

			else

				MODE=$ARG

			fi

		else

			WORK_DIR=$ARG

			echo "Set work dir: $WORK_DIR"

		fi

	done

	if [ ! -z "$MODE" ]; then

		echo "Unknown commandline argument $MODE"

	fi

	chroot_file_end

	if [ -z "$IMAGE_NAME" ]; then

		raise_error "image name was not set"

	fi

	INSTANCE_KEY="$(echo $IMAGE_NAME | tr "/:" "_")"

	check_runned

	local BUILDFILE="$WORK_DIR/Buildfile"

	if [ ! -f "$BUILDFILE" ]; then

		echo "Buildfile not found at: $BUILDFILE"

		return 1

	fi

	echo "Read $BUILDFILE"

	FULLROW=

	while read ROW; do

		FULLROW="$FULLROW$ROW"

		LASTCHAR=$((${#ROW}-1))

		if [ ! "${ROW:LASTCHAR:1}" = "\\" ]; then

			if [ "${FULLROW:0:5}" = "FROM " ]; then

				image_mount "${FULLROW:5}"

			elif [ "${ROW:0:4}" = "RUN " ]; then

				image_command "${FULLROW:4}"

			elif [ "${ROW:0:5}" = "COPY " ]; then

				image_copy ${FULLROW:5}

			elif [ ! "${FULLROW:0:1}" = "#" ]; then

				if [ ! -z "$FULLROW" ]; then

					echo "Unknown command: $FULLROW"

				fi 

			fi

			FULLROW=

		fi

		if [ ! -z "$COMMAND_ERROR" ]; then

			echo "Cancel build"

			IMAGE_NAME=""

			break

		fi

	done < "$BUILDFILE"

	image_unmount "$IMAGE_NAME"

}

run() {

	local IMAGE_NAME=

	local COMMAND=

	local SUBMOUNT=

	chroot_file_begin

	local MODE=

	for ARG in $@; do

		if [ ! -z "$COMMAND" ]; then

			COMMAND="$COMMAND $ARG"

		else

			if [ "$MODE" = "-e" ]; then

				ENVKEY="$(echo "$ARG" | cut -d'=' -f 1)"

				ENVVALUE="$(echo "$ARG" | cut -d'=' -f 2-)"

				chroot_file_env "$ENVKEY" "$ENVVALUE"

				MODE=

				continue

			elif [ "$MODE" = "-v" ]; then

				SUBMOUNT="$SUBMOUNT$ARG "

				echo "Add submount: $ARG"

				MODE=

				continue

			elif [ "$MODE" = "--name" ]; then

				echo "Set instance key (name): $ARG"

				INSTANCE_KEY="$ARG"

				MODE=

				continue

			fi

			if [ ! -z "$MODE" ]; then

				echo "Unknown commandline argument $MODE"

			fi

			MODE=

			if [ -z "$MODE" ]; then

				if [ "$ARG" = "--privileged=true" ]; then

					PRIVILEGED=1

					echo "Set privileged: true"

				elif [ "${ARG:0:1}" = "-" ]; then

					MODE=$ARG

				elif [ -z "$IMAGE_NAME" ]; then

					IMAGE_NAME=$ARG

					echo "Set image name: $IMAGE_NAME"

				elif [ -z "$COMMAND" ]; then

					COMMAND=$ARG

				fi

			fi

		fi

	done

	if [ ! -z "$MODE" ]; then

		echo "Unknown commandline argument $MODE"

	fi

	chroot_file_end

	echo "Set command: $COMMAND"

	if [ -z "$COMMAND" ]; then

		raise_error "command was not set"

	fi

	check_runned

	image_mount "$IMAGE_NAME" $SUBMOUNT

	image_command $COMMAND

	image_unmount

}

if [ "$1" = "import" ]; then

	set -- "${@:2}"

	import $@

elif [ "$1" = "build" ]; then

	set -- "${@:2}"

	build $@

elif [ "$1" = "run" ]; then

	set -- "${@:2}"

	run $@

else

	echo "Unknown command: $1"

	COMMAND_ERROR=1

fi

if [ ! -z "$COMMAND_ERROR" ]; then

	false

fi