#!/usr/bin/env bash

# This script sets up a Python virtualenv for the Web UI. This creates
# a new virtualenv and installs nodeenv inside the virtualenv.

set -e
trap "exit 1" INT

CURRDIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"

: ${VIRTUALENV_NAME:="linters"}
: ${VIRTUALENV_DIRECTORY:="${CURRDIR}/.virtualenv"}

: ${PYTHON:="$(which python)"}
: ${VIRTUALENV:="$(which virtualenv)"}

OLD_PYTHONPATH="${PYTHONPATH}"
PYTHONPATH=""

# If we already have a virtual environment activated,
# bail out and advise the user to deactivate.
OLD_VIRTUAL_ENV="${VIRTUAL_ENV}"
if [ "${OLD_VIRTUAL_ENV}" != "" ]; then
  echo "Please deactivate your current virtual environment in order to continue."
  echo "source deactivate"
  exit 1
fi

# Verify that python is installed.
if [ "${PYTHON}" = "" ]; then
  echo "You must have python installed in order to continue."
  exit 1
fi

# Old versions of virtualenv do not remove the bin directory in the
# virtual environment even when using `--clear`. We thus remove the
# entire directory in case the virtual environment already exists.
# See https://github.com/pypa/virtualenv/issues/2 for more info.
rm -rf ${VIRTUALENV_DIRECTORY}

PYTHON_MAJOR=$(${PYTHON} -c 'import sys; print(sys.version_info[0])')
PYTHON_MINOR=$(${PYTHON} -c 'import sys; print(sys.version_info[1])')

if [ "${PYTHON_MAJOR}" = "3" ]; then
  if [ "${PYTHON_MINOR}" -lt "6" ]; then
    echo "You must be running python 3.6 or newer in order to continue."
    echo "Consider running as 'PYTHON=python3 ${0}' or similar."
    exit 1
  else
    # Set up a virtual environment for the linters.
    ${PYTHON} -m venv --prompt="${VIRTUALENV_NAME}" ${VIRTUALENV_DIRECTORY}
  fi
else
  echo "You must be running python 3.6 or newer in order to continue."
  echo "Consider running as 'PYTHON=python3 ${0}' or similar."
  exit 1
fi

source ${VIRTUALENV_DIRECTORY}/bin/activate
pip install --upgrade pip
pip install -r ${CURRDIR}/pip-requirements.txt

# Add Node.js virtual environment to the existing virtual environment.
nodeenv -p

# Restart the virtual environment to then have npm available.
deactivate
source ${VIRTUALENV_DIRECTORY}/bin/activate

# Install the JavaScript linter in the virtual environment.
npm install -g eslint@5.1.0
deactivate