#!/bin/sh -e

# Invoked on termination if the last command failed
error() { >&2 echo "$(basename "$0"): ${*}"; }
error_envvar() { error "missing environment variable QEMUSH_NAME"; }
error_arg() { error "invalid argument \"${*}\""; }

# Assert that the QEMUSH_NAME variable is not null
trap error_envvar EXIT
[ -n "$QEMUSH_NAME" ]

# Determine the base dir to use
trap 'error_arg "$*"' EXIT
case "$1" in
    disk)
        basedir=disks
        extension=qcow2
        ;;
    socket)
        basedir=sockets
        ;;
    spice)
        basedir=spice
        extension=sock
        ;;
    *)
        false
        ;;
esac

# Release the trap
trap - EXIT

# Print the actual string
basedir="${HOME}/${basedir}"
[ -n "$extension" ] && extension=".${extension}"
printf %s/%s%s\\n "$basedir" "$QEMUSH_NAME" "$extension"