#!/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

if [ -z "${PYENV_ROOT}" ]; then
  PYENV_ROOT="$(pyenv-root)"
fi

resolve_link() {
  $(type -p greadlink readlink | head -1) "$1"
}

unset FORCE
unset QUIET

# Define `before_activate` and `after_activate` functions that allow
# plugin hooks to register a string of code for execution before or
# after activating a virtualenv.
declare -a before_hooks after_hooks

before_activate() {
  local hook="$1"
  before_hooks["${#before_hooks[@]}"]="$hook"
}

after_activate() {
  local hook="$1"
  after_hooks["${#after_hooks[@]}"]="$hook"
}

# Load plugin hooks.
OLDIFS="$IFS"
IFS=$'\n' scripts=(`pyenv-hooks activate`)
IFS="$OLDIFS"
for script in "${scripts[@]}"; do source "$script"; done

while [ $# -gt 0 ]; do
  case "$1" in
  "--complete" )
    # Provide pyenv completions
    echo --unset
    exec pyenv-virtualenvs --bare
    ;;
  "-f" | "--force" )
    FORCE=1
    ;;
  "-q" | "--quiet" )
    QUIET=1
    ;;
  "--unset" )
    exec pyenv-sh-deactivate
    ;;
  "-v" | "--verbose" )
    unset QUIET
    PYENV_VIRTUALENV_VERBOSE_ACTIVATE=1
    ;;
  * )
    break
    ;;
  esac
  shift 1
done

get_current_versions() {
  local IFS=:
  current_versions=($(pyenv-version-name 2>/dev/null))
}

no_shell=
versions=("$@")
current_versions=()
if [ -z "${versions}" ]; then
  no_shell=1
  get_current_versions
  versions=("${current_versions[@]}")
fi

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

venv="${versions}"

if [ -n "${VIRTUAL_ENV}" ]; then
  # exit as success if a non-pyenv virtualenv is active
  if [[ -z $PYENV_VIRTUAL_ENV || $PYENV_VIRTUAL_ENV != "$VIRTUAL_ENV" ]]; then
    if [ -z "${FORCE}" ]; then
      if [ -z "${QUIET}" ]; then
        echo "pyenv-virtualenv: virtualenv \`${VIRTUAL_ENV}' is already activated" 1>&2
      fi
      echo "true"
      exit 0
    fi
  fi
fi

if ! pyenv-virtualenv-prefix "${venv}" 1>/dev/null 2>&1; then
  # fallback to virtualenv of current version
  [ -n "${current_versions}" ] || get_current_versions
  new_venv="${current_versions%/envs/*}/envs/${venv}"
  if pyenv-virtualenv-prefix "${new_venv}" 1>/dev/null 2>&1; then
    venv="${new_venv}"
    versions[0]="${new_venv}"
  else
    if [ -z "${QUIET}" ]; then
      echo "pyenv-virtualenv: version \`${venv}' is not a virtualenv" 1>&2
    fi
    echo "false"
    exit 1
  fi
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 [ -L "${prefix}" ]; then
  prefix="$(resolve_link "${prefix}" 2>/dev/null)"
fi

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

pyenv-sh-deactivate --force --quiet || true

# Execute `before_activate` hooks.
for hook in "${before_hooks[@]}"; do eval "$hook"; done

if [ -n "$PYENV_VIRTUALENV_VERBOSE_ACTIVATE" ]; then
  echo "pyenv-virtualenv: activate ${venv}" 1>&2
fi

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 "$shell" in
  fish )
    cat <<EOS
set -gx PYENV_VERSION "${versions[*]}";
set -gx PYENV_ACTIVATE_SHELL 1;
EOS
    ;;
  * )
    cat <<EOS
export PYENV_VERSION="${versions[*]}";
export PYENV_ACTIVATE_SHELL=1;
EOS
    ;;
  esac
  IFS="$OLDIFS"
fi

# virtualenv/venv
case "${shell}" in
fish )
  cat <<EOS
set -gx PYENV_VIRTUAL_ENV "${prefix}";
set -gx VIRTUAL_ENV "${prefix}";
EOS
  ;;
* )
  cat <<EOS
export PYENV_VIRTUAL_ENV="${prefix}";
export VIRTUAL_ENV="${prefix}";
EOS
  ;;
esac

# anaconda/miniconda
if [ -d "${prefix}/conda-meta" ] ||
     [ -x "${prefix}/bin/conda" ]; then
  if [[ "${prefix}" != "${prefix%/envs/*}" ]]; then
    CONDA_DEFAULT_ENV="${venv##*/envs/}"
  else
    CONDA_DEFAULT_ENV="root"
  fi
  case "${shell}" in
  fish )
    echo "set -gx 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
set -gx _OLD_VIRTUAL_PYTHONHOME "${PYTHONHOME}";
set -e PYTHONHOME;
EOS
    ;;
  * )
    cat <<EOS
export _OLD_VIRTUAL_PYTHONHOME="${PYTHONHOME}";
unset PYTHONHOME;
EOS
    ;;
  esac
fi

PYENV_VIRTUALENV_DISABLE_PROMPT="${PYENV_VIRTUALENV_DISABLE_PROMPT:-${PYENV_VIRTUAL_ENV_DISABLE_PROMPT}}"
PYENV_VIRTUALENV_DISABLE_PROMPT="${PYENV_VIRTUALENV_DISABLE_PROMPT:-${VIRTUAL_ENV_DISABLE_PROMPT}}"

if [ -z "${PYENV_VIRTUALENV_DISABLE_PROMPT}" ]; then
  case "${shell}" in
  fish )
    if [ -z "${QUIET}" ]; then
      cat <<EOS
functions -e _pyenv_old_prompt              # remove old prompt function if exists. 
                                            # since everything is in memory, it's safe to
                                            # remove it.
functions -c fish_prompt _pyenv_old_prompt  # backup old prompt function

# from python-venv
function fish_prompt
    set -l prompt (_pyenv_old_prompt)       # call old prompt function first since it might 
                                            # read exit status
    echo -n "(${venv}) "                    # add virtualenv to prompt
    string join -- \n \$prompt              # handle multiline prompts
end
EOS
    fi
    ;;
  * )
    if [ -z "${PYENV_VIRTUALENV_PROMPT}" ]; then
      PYENV_VIRTUALENV_PROMPT="(${venv})"
    else
      PYENV_VIRTUALENV_PROMPT="${PYENV_VIRTUALENV_PROMPT/\{venv\}/${venv}}"
    fi
    cat <<EOS
export _OLD_VIRTUAL_PS1="\${PS1:-}";
export PS1="${PYENV_VIRTUALENV_PROMPT} \${PS1:-}";
EOS
    ;;
  esac
fi

# conda package anaconda/miniconda scripts (#173)
if [ -d "${prefix}/conda-meta" ] ||
     [ -x "${prefix}/bin/conda" ]; then
  shopt -s nullglob
  case "${shell}" in
  fish )
    # conda 4.4 and above
    for script in "${prefix}/etc/fish/conf.d"/*.fish; do
      echo "source \"${script}\";"
    done
    ;;
  * )
    CONDA_PREFIX="$prefix"
    echo "export CONDA_PREFIX=\"${CONDA_PREFIX}\";"
    for script in "${prefix}/etc/conda/activate.d"/*.sh; do
      echo ". \"${script}\";"
    done
    # conda 4.4 and above
    for script in "${prefix}/etc/profile.d"/*.sh; do
      echo ". \"${script}\";"
    done
    ;;
  esac
  shopt -u nullglob
fi

# Execute `after_activate` hooks.
for hook in "${after_hooks[@]}"; do eval "$hook"; done