#!/bin/bash

set -e

OLDDIR=`pwd`

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

cd "$OLDDIR"

INSTANCE_NAME=`uuidgen`

INSTANCE_NAME="chrooter-$INSTANCE_NAME"

PRIVILEGED=

IMAGE_MOUNT_DIR=

COMMAND_ERROR=

PREFIX="$CHROOTER_PREFIX"

if [ -z "$PREFIX" ]; then

    PREFIX="/tmp"

fi

image_mount_add() {

	echo "Mount: $1 -> $2"

	sudo mkdir -p "$IMAGE_MOUNT_DIR$2"

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

	echo "umount -f \"$IMAGE_MOUNT_DIR$2\" \\" >> "/$PREFIX/$INSTANCE_NAME.umount.sh"

	echo "|| (echo \"next try after 10 seconds\" && sleep 10 && umount -f \"$IMAGE_MOUNT_DIR$2\") \\" >> "/$PREFIX/$INSTANCE_NAME.umount.sh"

	echo "|| (echo \"final try after 10 seconds\" && sleep 10 && umount -f \"$IMAGE_MOUNT_DIR$2\")" >> "/$PREFIX/$INSTANCE_NAME.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.tgz"

	echo "Unpack image: $1"

	IMAGE_MOUNT_DIR="/$PREFIX/$INSTANCE_NAME"

	mkdir -p "$IMAGE_MOUNT_DIR"

	cd "$IMAGE_MOUNT_DIR"

	sudo tar -xzf $IMAGE_FILE

	cd "$OLDDIR"

	echo "Add -.chroot.sh file"

	sudo mv "/$PREFIX/$INSTANCE_NAME.chroot.sh" "$IMAGE_MOUNT_DIR"

	sudo chmod a+x "$IMAGE_MOUNT_DIR/$INSTANCE_NAME.chroot.sh"

    set -- "${@:2}"

	echo "Mount subs: $@"

	echo "#!/bin/sh" > "/$PREFIX/$INSTANCE_NAME.umount.sh"

	echo "" >> "/$PREFIX/$INSTANCE_NAME.umount.sh"

	echo "set -e" >> "/$PREFIX/$INSTANCE_NAME.umount.sh"

	chmod a+x "/$PREFIX/$INSTANCE_NAME.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 mkdir -p $IMAGE_MOUNT_DIR/etc && cp /etc/resolv.conf $IMAGE_MOUNT_DIR/etc

}

image_unmount() {

	echo "Unmount image"

	if [ -z "$IMAGE_MOUNT_DIR" ]; then

		echo "Image not mounted"

		return 1

	fi

	echo "Unmount subs"

	sudo "/$PREFIX/$INSTANCE_NAME.umount.sh"

	sudo rm -f "/$PREFIX/$INSTANCE_NAME.umount.sh"

	echo "Remove -.chroot.sh file"

	sudo rm -f "$IMAGE_MOUNT_DIR/$INSTANCE_NAME.chroot.sh"

	if [ ! -z $1 ]; then

		echo "Save image: $1"

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

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

		local IMAGE_DIR=`dirname "$IMAGE_FILE"`

		mkdir -p "$IMAGE_DIR"

		cd "$IMAGE_MOUNT_DIR"

		sudo tar -czf $IMAGE_FILE .

		cd "$OLDDIR"

	fi

	echo "Remove unpacked image"

	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

	if ! env -i /usr/bin/sudo -i chroot "$IMAGE_MOUNT_DIR" "/$INSTANCE_NAME.chroot.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/$2"; then

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

		return 1

	fi

}

chroot_file_begin() {

	echo "#!/bin/sh" > "/$PREFIX/$INSTANCE_NAME.chroot.sh"

	echo "" >> "/$PREFIX/$INSTANCE_NAME.chroot.sh"

}

chroot_file_env() {

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

	echo "export $1=\"$2\"" >> "/$PREFIX/$INSTANCE_NAME.chroot.sh"

}

chroot_file_end() {

	echo "\$@" >> "/$PREFIX/$INSTANCE_NAME.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 "/:" "_")"

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

	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: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

    		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

		echo "Image name was not set"

		return 1

	fi

	local DOCKERFILE="$WORK_DIR/Dockerfile"

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

		echo "Dockerfile not found at: $DOCKERFILE"

		return 1

	fi

	echo "Read $DOCKERFILE"

	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 < "$DOCKERFILE"

	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 name: $ARG (not uses)"

				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

		echo "Command was not set"

		return 1

	fi

	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