#!/bin/sh -Efu
VBoxManage() {
  if [ "$1" = "-x" ]; then
    shift
    echo "# VBoxManage $*" >&2
  fi
  LC_ALL=en_US.UTF-8 /usr/bin/VBoxManage "$@" || exit 1
}

VBSnap=vbsnap

Usage="`basename $0` base clone [port] [intnet2 intnet3 intnet4]"
die() { # Message [command]
  echo "$1" >&2
  test -z "$2" || eval $2 >&2
  echo -e "\nUsage:\n$Usage" >&2
  exit 1
}

test $# = 0 && die "No VM specified" "VBoxManage list vms"
Base="$1"
Group="`VBoxManage showvminfo "$Base" | sed -En 's/^Groups:[[:space:]]+([^,[:space:]]+).*/\1/p'`"
ReGRoup="Groups:[[:space:]]+$Group(,|$)"
ReUART="^UART.*attached to tcp.*'([[:digit:]]+)'.*"
ReName="^Name:[[:space:]]*"
test -z "$Base" -o -z "$Group" && die "Unknown VM «$Base»" "VBoxManage list vms"
# NGroup=`VBoxManage list -l vms | grep -E "$ReGRoup" | wc -l`
MaxPort=$(VBoxManage list -l vms | sed -En "\@$ReGRoup@,/^$/{s/$ReUART/\1/p}" | sort -n | tail -1)
shift
Port=$((1+MaxPort))

test $# = 0 && {
  echo "Clones in group '$Group' ($Base):"
  VBoxManage list -l vms | sed -En "/^Name/h;\#$ReGRoup#{x;s/$ReName//p}"
  echo -e "\nFree port: $Port"
  echo -e "\nUsage:\n$Usage" >&2
  exit 1
}
Name="$1"
shift

if [ "$Name" = "ERASE!" ]; then
  VBoxManage list -l vms | sed -En "/$ReName$Base/b;/^Name/h;\#$ReGRoup#{x;s/$ReName//p}" |
    while read Par; do 
      VBoxManage -x unregistervm --delete "$Par"
    done
    VBoxManage -x snapshot "$Base" delete "$VBSnap"
  exit 0
fi

Nets=""
SKU="$Port"
NNet=2
for Par; do
  case "$Par" in
    [a-zA-Z]*) # Net
      Nets="$Nets --nic$NNet intnet --intnet$NNet $Par --cableconnected$NNet on"
      NNet=$((NNet+1))
      SKU="$SKU.$Par"
      ;;
    ''|*[^0-9]*) die "Incorrent net name «$Par»" "VBoxManage list intnets" ;;
    *) # Port
      Port="$Par" ;;
  esac
done

VBoxManage snapshot "$Base" list | grep -q "Name: $VBSnap (UUID:.*" || {
  VBoxManage -x snapshot "$Base" take "$VBSnap"
}

HName="`echo $Name | tr -dc '[:alnum:]'`"
VBoxManage -x clonevm "$Base" --groups="$Group" --name="$Name" --options=Link --register --snapshot "$VBSnap"
VBoxManage -x modifyvm "$Name" --uartmode1 tcpserver $Port $Nets
VBoxManage -x setextradata "$Name" VBoxInternal/Devices/pcbios/0/Config/DmiSystemVendor "$HName"
VBoxManage -x setextradata "$Name" VBoxInternal/Devices/pcbios/0/Config/DmiSystemSKU "$SKU"