#!/bin/sh

if [ $# -ne 2 ]
then
  printf "usage: $0 [get|exists|path|dir|find] key\n"
  exit 0
fi

if [ $1 == "set" ]
then
  printf "Configuration is immutable\n" 1>&2
  exit 1
fi

if [ ! -d /Database ]
then
  mkdir -p /Database
  if [ -d /sys/bus/vmbus ]; then
    # Running on a Hyper-V hypervisor
    /sbin/9pmount-vsock listen db /Database
  else
    mount -t 9p -o trans=virtio,dfltuid=1001,dfltgid=50,version=9p2000 db /Database
  fi
  if [ $? -ne 0 ]
  then
    rm -rf /Database
    printf "Could not mount configuration database\n" 1>&2
    exit 1
  fi
fi

DATABASE="com.docker.driver.amd64-linux"
BASE="/Database/branch/master/ro/${DATABASE}"

KEY=$(echo $2 | sed 's@^/@@')

if [ $1 == "exists" ]
then
  [ -d ${BASE}/${KEY} ] && exit 0
  [ -f ${BASE}/${KEY} ] || exit 1
  VALUE="$(cat ${BASE}/${KEY} | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//')"
  [ -z "${VALUE}" ] && exit 1
  exit 0
fi

if [ $1 == "dir" ]
then
  [ -d ${BASE}/${KEY} ] && exit 0 || exit 1
fi

if [ $1 == "get" ]
then
  if [ -f ${BASE}/${KEY} ]
  then
    cat ${BASE}/${KEY}
    exit 0
  else
    printf "No such key: ${KEY}\n" 1>&2
    exit 1
  fi
fi

if [ $1 == "path" ]
then
  if [ -e ${BASE}/${KEY} ]
  then
    printf ${BASE}/${KEY}
    exit 0
  else
    printf "No such key: ${KEY}\n" 1>&2
    exit 1
  fi
fi

if [ $1 == "find" ]
then
  if [ -e ${BASE}/${KEY} ]
  then
    find ${BASE}/${KEY} -type f | sed "s@^${BASE}@@g"
    exit 0
  else
    printf "No such key: ${KEY}\n" 1>&2
    exit 1
  fi
fi

printf "usage: $0 [get|exists|path|dir|find] key\n"
exit 1
