#!/usr/bin/env bash

# Execute things in an ephemeral nix environment context, with similar
# syntax as `guix environment --ad-hoc`:
# nix-environment <package_1> [ ... <package_n> ] -- \
#   command [ <arg_1> [ ... <arg_n>]]

EL_BIN=/nix/var/nix/profiles/execline/bin

while (( $# >= 1 )); do
  if [[ $1 == "--" ]]; then
    shift
    break
  fi
  packages+=( "$1" )
  shift
done

export PACKAGES=$(PATH=${EL_BIN}:$PATH execlineb -c 'dollarat -d ""' "${packages[@]}")

exec ${EL_BIN}/execlineb -c "
  ${EL_BIN}/import -u EL_BIN"'
  ${EL_BIN}/import -u -s -d "" PACKAGES
  nix-shell -p $PACKAGES --run
    "exec '"'"'${EL_BIN}/elgetpositionals'"'"' \\$@"
' "$@"