#! /usr/bin/env bash

help() {
	echo "editvm.sh DISTRO [CMD] [ARGS]"
	echo "  Stops the ramdisk and start editing a VM template"
	echo "  --copy PATHSRC PATHDEST: copy PATHSRC into the container as PATHDEST"
}

KEEP=0

SYSDIR="/ramdisk/sys"
TMPDIR="/ramdisk/tmp"

if [ $# -lt 2 ]; then
	help
	exit 0
fi

# Files to copy into container
COPY=()
COPYDEST=()

while true; do
	case "$1" in
		"-h"|"--help")
			help
			exit 0
			;;
		"--copy")
			shift
			PATHSRC="$1"
			if [ ! -e "$PATHSRC" ]; then
				echo "COPY ERROR: File/Folder "$PATHSRC" does not exist."
				exit 1
			fi
			shift
			PATHDEST="$1"
			COPY+=("$PATHSRC")
			COPYDEST+=("$PATHDEST")
			shift
			;;
		*)
			# Optional args processing finished
			# If no first argument is passed, syntax error
			if [[ "$1" = "" ]]; then
				help
				exit 1
			fi
			TYPE="$1"
			shift
			break
			;;
	esac
done

if systemctl is-active ramdisk; then
	echo "ERROR: Please stop ramdisk.service first"
	exit 1
fi

TEMPLATE=/var/lib/lxc/"$TYPE".template

if [ ! -f "$TEMPLATE" ]; then
	echo "ERROR: No such VM type "$TYPE""
	exit 1
fi

export VMNAME="$TYPE-TEMPLATE"
echo "$VMNAME"

export LXCROOTFS=/ramdisk/persist/$TYPE
# Check if the rootfs exists... maybe the template actually calls another rootfs
if [ ! -d "$LXCROOTFS" ]; then
	echo "ERROR: The container template "$TYPE" does not have its own rootfs. Maybe it's using another rootfs?"
	echo "Check the lxc.rootfs.path line in "$TEMPLATE" file to be sure."
	exit 1
fi

LXCDIR=/var/lib/lxc/"$VMNAME"
mkdir "$LXCDIR"
envsubst < "$TEMPLATE" > "$LXCDIR"/config

ROOTFS="$LXCROOTFS"
echo "template" > "$ROOTFS"/etc/hostname

# Copy files into the VM
for fileIndex in ${!COPY[@]}; do
	PATHSRC="${COPY[$fileIndex]}"
	PATHDEST="$ROOTFS""${COPYDEST[$fileIndex]}"
	# Create parent dirs
	PARENTPATHDEST="$(dirname "$PATHDEST")"
	mkdir -p "$PARENTPATHDEST"
	cp --dereference -r "$PATHSRC" "$PATHDEST"
done

CMD="$1"
shift

if [[ "$CMD" != "" ]]; then
	#lxc-execute -n "$VMNAME" -- "$CMD" "$@"
	lxc-start -n "$VMNAME"
	lxc-attach -n "$VMNAME" -- "$CMD" "$@"
	if [ $KEEP -eq 0 ]; then
		lxc-stop --kill "$VMNAME"
		# Don't destroy VM because we want to keep the rootfs
		# (we are just editing it live)
		# lxc-destroy -n "$VMNAME"
		rm -R /var/lib/lxc/"$VMNAME"
	fi
else
	lxc-start -n "$VMNAME"
	lxc-attach -n "$VMNAME" bash
	if [ $KEEP -eq 0 ]; then
		lxc-stop --kill "$VMNAME"
		# Don't destroy VM because we want to keep the rootfs
		# (we are just editing it live)
		#lxc-destroy -n "$VMNAME"
		rm -R /var/lib/lxc/"$VMNAME"
	fi
fi