#!/bin/sh

set -e

# defaults
RAM=512
DISK=20
CPUS=1
STORAGE_POOL=default
QEMU_URI=qemu:///system
SUITE=wheezy
CONSOLE='console=tty0 console=ttyS0,115200n8'
DEBUG=0
WIPE=0
RESTART=0

while [ -n "$1" ]; do
  case "$1" in
    (--debug)
      DEBUG=1
      ;;
    (-S|--suite)
      shift
      if [ -z "$1" ]; then
        echo >&2 'E: --suite/-S needs suite argument'
        exit 1
      fi
      SUITE="$1"
      ;;
    (-n|--name)
      shift
      if [ -z "$1" ]; then
        echo >&2 'E: --name/-n needs hostname argument'
        exit 1
      fi
      HOSTNAME="$1"
      ;;
    (-i|--ipaddress)
      shift
      if [ -z "$1" ]; then
        echo >&2 'E: --ipaddress/-i needs IP address/netmask'
        exit 1
      fi
      case "$1" in
        (*/*) :;;
        (*)
          echo >&2 'E: missing netmask'
          exit 1
          ;;
      esac
      IPADDRESS="$1"
      ;;
    (-d|--dns)
      shift
      if [ -z "$1" ]; then
        echo >&2 'E: --dns/-d needs IP address'
        exit 1
      fi
      NAMESERVER="$1"
      ;;
    (-g|--gateway)
      shift
      if [ -z "$1" ]; then
        echo >&2 'E: --gateway/-g needs IP address'
        exit 1
      fi
      GATEWAY="$1"
      ;;
    (-r|--ram)
      shift
      if [ -z "$1" ]; then
        echo >&2 'E: --ram/-r needs number (megabytes)'
        exit 1
      fi
      RAM="$1"
      ;;
    (-s|--size)
      shift
      if [ -z "$1" ]; then
        echo >&2 'E: --size/-s needs size argument'
        exit 1
      fi
      DISK="$1"
      ;;
    (-a|--arch)
      shift
      if [ -z "$1" ]; then
        echo >&2 'E: --arch/-a needs arch argument'
        exit 1
      fi
      ARCH="$1"
      ;;
    (-m|--mac)
      shift
      if [ -z "$1" ]; then
        echo >&2 'E: --mac/-m needs mac address argument'
        exit 1
      fi
      MAC="$1"
      ;;
    (-c|--cpus)
      shift
      if [ -z "$1" ]; then
        echo >&2 'E: --cpus/-c needs integer argument'
        exit 1
      fi
      CPUS="$1"
      ;;
    (--debug)
      DEBUG=1
      set -vx
      ;;
    (--wipe)
      WIPE=1
      ;;
    (--restart)
      RESTART=1
      ;;
  esac
  shift
done

if [ -z "${HOSTNAME:-}" ]; then
  echo >&2 'E: hostname is required'
  exit 2
fi

BASEDIR=$(cd ${0%/*}; pwd)

tmpdir=$(mktemp -d)
tar -C $BASEDIR/preseed/$SUITE -cf $tmpdir/commands.tar commands

extra_kargs="auto $CONSOLE \
netcfg/hostname=${HOSTNAME%%.*} \
netcfg/domain=${HOSTNAME#*.}"

extra_opts=
if [ -n "$DEBUG" ]; then
  extra_opts='--debug'
fi

if [ -n "$IPADDRESS" ]; then
  if [ -z "$GATEWAY" ] && [ -x $(command -v ipcalc) ]; then
    # default to the first IP in the network
    GATEWAY=$(ipcalc $IPADDRESS | grep HostMin | awk '{print $2}')
  fi
  NETMASK="${IPADDRESS#*/}"
  IPADDRESS="${IPADDRESS%/*}"
  : ${NAMESERVER:=$GATEWAY}

  extra_kargs="$extra_kargs netcfg/disable_dhcp=true \
  netcfg/get_ipaddress=$IPADDRESS \
  netcfg/get_netmask=$NETMASK \
  netcfg/get_gateway=$GATEWAY \
  netcfg/get_nameservers=$NAMESERVER"

  BRIDGE=wan

else
  extra_kargs="$extra_kargs netcfg/disable_dhcp=false"
  BRIDGE=virt-br
fi

if [ -z "$ARCH" ]; then
  ARCH=$(dpkg --print-architecture)
fi

if [ -z "$MAC" ]; then
  bytes=$(dd status=noxfer if=/dev/urandom bs=3 count=1 | hexdump -v -e '/1 ":%02X"')
  MAC=52:54:00$bytes
fi

cat >&2 <<_eof
  hostname: $HOSTNAME
      arch: $ARCH
     suite: $SUITE
       ram: $RAM MiB
      disk: $DISK GiB
      cpus: $CPUS
      wipe: $WIPE
   console: $CONSOLE
   restart: $RESTART
net bridge: $BRIDGE
macaddress: $MAC
_eof
if [ -n "$IPADDRESS" ]; then
  cat >&2 <<_eof
 ipaddress: $IPADDRESS
   netmask: $NETMASK
   gateway: $GATEWAY
nameserver: $NAMESERVER
_eof
else
  cat >&2 <<_eof
      dhcp: true
_eof
fi

echo >&2

virsh --connect=$QEMU_URI vol-create-as $STORAGE_POOL virt-$HOSTNAME ${DISK}G
if [ $WIPE = 1 ]; then
  echo >&2 "Wiping disk…"
  virsh --connect=$QEMU_URI vol-wipe --pool $STORAGE_POOL --algorithm zero virt-$HOSTNAME
fi

if [ $DEBUG = 1 ]; then
  DEBUGFLAG=--debug
  extra_args="$extra_args DEBCONF_DEBUG=5"
fi

virt-install --connect=$QEMU_URI \
  ${DEBUGFLAG:-} \
  -n $HOSTNAME \
  --vcpus=$CPUS \
  -r $RAM \
  --disk vol=$STORAGE_POOL/virt-$HOSTNAME \
  --network bridge=$BRIDGE,mac=$MAC \
  --graphics=vnc \
  --serial=pty \
  --watchdog i6300esb,action=reset \
  --os-variant=debianwheezy \
  --initrd-inject=$BASEDIR/preseed/$SUITE/preseed.cfg \
  --initrd-inject=$tmpdir/commands.tar \
  --extra-args="$extra_kargs" \
  --prompt --noautoconsole --autostart $extra_opts \
  -l $BASEDIR/installer-amd64/$SUITE \
  "$@"

virsh --connect=$QEMU_URI console $HOSTNAME

if [ $RESTART = 1 ]; then
  sleep 5
  virsh --connect=$QEMU_URI "start $HOSTNAME; console $HOSTNAME"
fi