#!/usr/bin/env bash
#
# Summary: Activate virtual environment
#
# Usage: pyenv activate <virtualenv>
#        pyenv activate --unset
#
# Activate a Python virtualenv environment in current shell.
# This acts almost as same as `pyenv shell`, but this invokes the `activate`
# script in your shell.
#
# <virtualenv> should be a string matching a Python version known to pyenv.

set -e
[ -n "$PYENV_DEBUG" ] && set -x

unset DEACTIVATE
unset FORCE
unset QUIET
unset VERBOSE

while [ $# -gt 0 ]; do
  case "$1" in
  "--complete" )
    # Provide pyenv completions
    echo --unset
    exec pyenv-virtualenvs --bare
    ;;
  "--deactivate" )
    DEACTIVATE=1
    ;;
  "--force" )
    FORCE=1
    ;;
  "--no-error" | "--quiet" )
    QUIET=1
    ;;
  "--unset" )
    echo "pyenv deactivate"
    exit
    ;;
  "--verbose" )
    VERBOSE=1
    ;;
  * )
    break
    ;;
  esac
  shift 1
done

no_shell=
versions=("$@")
if [ -z "${versions}" ]; then
  no_shell=1
  OLDIFS="$IFS"
  IFS=: versions=($(pyenv-version-name))
  IFS="$OLDIFS"
fi

if [ -z "${PYENV_VIRTUALENV_INIT}" ]; then
  # Backward compatibility issue
  # https://github.com/yyuu/pyenv-virtualenv/issues/26
  no_shell=
fi

venv="${versions}"

if ! pyenv-virtualenv-prefix "${venv}" 1>/dev/null 2>&1; then
  if [ -z "$QUIET" ]; then
    echo "pyenv-virtualenv: version \`${venv}' is not a virtualenv" 1>&2
  fi
  echo "false"
  exit 1
fi

# exit as error if there are multiple virtualenvs
# https://github.com/yyuu/pyenv-virtualenv/issues/105
for version in "${versions[@]}"; do
  if [[ "${version}" != "${venv}" ]]; then
    if pyenv-virtualenv-prefix "${version}" 1>/dev/null 2>&1; then
      if [ -z "$QUIET" ]; then
        echo "pyenv-virtualenv: cannot activate multiple versions at once: ${versions[@]}" 1>&2
      fi
      echo "false"
      exit 1
    fi
  fi
done

shell="${PYENV_SHELL:-${SHELL##*/}}"
prefix="$(pyenv-prefix "${venv}")"

if [[ "${VIRTUAL_ENV}" == "${prefix}" ]]; then
  if [ -z "${QUIET}" ]; then
    echo "pyenv-virtualenv: version \`${venv}' is already activated" 1>&2
  fi
  echo "true"
  exit 0
fi

if [[ "${PYENV_DEACTIVATE}" == "${prefix}" ]]; then
  if [ -z "${FORCE}" ]; then
    if [ -z "${QUIET}" ]; then
      echo "pyenv-virtualenv: \`${venv}' is marked deactivated. use \`pyenv activate --force ${venv}' to activate forcibly." 1>&2
    fi
    echo "false"
    exit 1
  fi
fi

# Display setup instruction, if pyenv-virtualenv has not been initialized.
# if 'pyenv virtualenv-init -' is not found in "$profile"
if [ -z "$PYENV_VIRTUALENV_INIT" ]; then
  pyenv-virtualenv-init >&2 || true
fi

if [ -n "${DEACTIVATE}" ]; then
  pyenv-sh-deactivate ${QUIET+--quiet} ${VERBOSE+--verbose}
fi

echo "pyenv-virtualenv: activate ${venv}" 1>&2

if [ -z "$no_shell" ]; then
  # shell version set in pyenv-sh-activate should be unset
  # https://github.com/yyuu/pyenv-virtualenv/issues/61
  OLDIFS="$IFS"
  IFS=:
  case "$shell" in
  fish )
    cat <<EOS
setenv PYENV_VERSION "${versions[*]}";
setenv PYENV_ACTIVATE_SHELL 1;
EOS
    ;;
  * )
    cat <<EOS
export PYENV_VERSION="${versions[*]}";
export PYENV_ACTIVATE_SHELL=1;
EOS
    ;;
  esac
  IFS="$OLDIFS"
fi

# virtualenv/pyvenv
case "${shell}" in
fish )
  cat <<EOS
set -e PYENV_DEACTIVATE;
setenv VIRTUAL_ENV "${prefix}";
EOS
  ;;
* )
  cat <<EOS
unset PYENV_DEACTIVATE;
export VIRTUAL_ENV="${prefix}";
EOS
  ;;
esac

# anaconda/miniconda
if [ -x "${prefix}/bin/conda" ]; then
  if [[ "${venv}" != "${venv%/envs/*}" ]]; then
    CONDA_DEFAULT_ENV="${venv##*/envs/}"
  else
    CONDA_DEFAULT_ENV="root"
  fi
  case "${shell}" in
  fish )
    echo "setenv CONDA_DEFAULT_ENV \"${CONDA_DEFAULT_ENV}\";"
    ;;
  * )
    echo "export CONDA_DEFAULT_ENV=\"${CONDA_DEFAULT_ENV}\";"
    ;;
  esac
fi

if [ -n "${PYTHONHOME}" ]; then
  case "${shell}" in
  fish )
    cat <<EOS
setenv _OLD_VIRTUAL_PYTHONHOME "${PYTHONHOME}";
set -e PYTHONHOME;
EOS
    ;;
  * )
    cat <<EOS
export _OLD_VIRTUAL_PYTHONHOME="${PYTHONHOME}";
unset PYTHONHOME;
EOS
    ;;
  esac
fi