#! /usr/bin/env bash

KEEP=0

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

help() {
	echo "testvm.sh DISTRO [CMD] [ARGS]"
	echo "  -k|--keep: Don't destroy the VM after running"
	echo "  --copy PATHSRC PATHDEST: copy PATHSRC into the container as PATHDEST"
}

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
		;;
	"-k"|"--keep")
		KEEP=1
		shift
		;;
	"--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

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

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

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

export LXCROOTFS="overlayfs:/ramdisk/sys/$TYPE:/ramdisk/tmp/$VMNAME"
echo "$LXCROOTFS"
LXCDIR=/var/lib/lxc/"$VMNAME"
mkdir "$LXCDIR"
envsubst < "$TEMPLATE" > "$LXCDIR"/config

ROOTFS="$TMPDIR"/"$VMNAME"
mkdir -p "$ROOTFS"/etc/
echo "$VMNAME" > "$ROOTFS"/etc/hostname

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

CMD="$1"
shift

if [[ "$CMD" != "" ]]; then
	lxc-start -n "$VMNAME"
	lxc-attach -n "$VMNAME" -- "$CMD" "$@"
	if [ $KEEP -eq 0 ]; then
		lxc-stop --kill "$VMNAME"
		lxc-destroy -n "$VMNAME"
	fi
else
	lxc-start -n "$VMNAME"
	lxc-attach -n "$VMNAME" bash
	if [ $KEEP -eq 0 ]; then
		lxc-stop --kill "$VMNAME"
		lxc-destroy -n "$VMNAME"
	fi
fi