pup

#!/usr/bin/env bash

PIP_COMMAND=$(which pip3 || which pip)
PYTHON_COMMAND=$(which python3 || which python)
WORKSPACE=$(pwd)
PUP_DIR=${WORKSPACE}/.pup
PUP_PACKAGES_DIR="${PUP_DIR}/packages"
PUP_BIN_DIR="${PUP_DIR}/bin"
PUP_CACHE="${HOME}/.pup_cache"

_create_dir_unless_exists() {
  local dir=$1
  if [ ! -d ${dir} ]
  then
    mkdir -p ${dir}
  fi
}

_setup() {
  _create_dir_unless_exists "${PUP_CACHE}"
  _create_dir_unless_exists "${PUP_DIR}"
  _create_dir_unless_exists "${PUP_PACKAGES_DIR}"
  _create_dir_unless_exists "${PUP_BIN_DIR}"
}

install() {
  "${PIP_COMMAND}" install \
    --target="${PUP_PACKAGES_DIR}" \
    --no-binary :all: \
    --cache-dir ${PUP_CACHE} \
    --install-option="--install-scripts=${PUP_BIN_DIR}" "${@}"
}

exec() {
  local command=$1
  shift
  PYTHONPATH=${PUP_PACKAGES_DIR} "${PUP_BIN_DIR}/${command}" "${@}"
}

run() {
  PYTHONPATH=${PUP_PACKAGES_DIR} "${PYTHON_COMMAND}" "${@}"
}

help() {
  echo "Install or run Python packages"
}

command=$1
shift

_setup

if [[ "$command" == "install" ]]
then
  install ${@}
elif [[ "$command" == "exec" ]]
then
  exec ${@}
elif [[ "$command" == "run" ]]
then
  run ${@}
else
  help
fi