PYENV_DIR="${PYENVS_HOME:-${XDG_DATA_HOME:-$HOME/.local/share}/virtualenv}"
PS1_DEFAULT="$PS1"
PS1_PRE="${PYENV_PROMPT:- %F{yellow\}%F{reset\} }"
function chpwd_activate(){
  [[ "$(pwd)" == "/" ]] && return 0
  for pydir in $(ls $PYENV_DIR); do
    if [[ "$(pwd|sed -e s@/@_@g|cut -c2-)" =~ "^${pydir}$" ]] || [[ "r-$(pwd|sed -e s@/@_@g|cut -c2-)" =~ "^${pydir}(_.+)?$" ]]; then
      if [ "x$VIRTUAL_ENV" != "x$PYENV_DIR/$pydir" ]; then
        export PS1="$PS1_PRE$PS1_DEFAULT"
        export VIRTUAL_ENV_DISABLE_PROMPT=1
        source "$PYENV_DIR/$pydir/bin/activate"
        unset VIRTUAL_ENV_DISABLE_PROMPT 
      fi
      return
    fi
  done
  if [ "x$VIRTUAL_ENV" != "x" ]; then
    export PS1="$PS1_DEFAULT"
    deactivate
  fi
}

function venv(){
  [[ "$(pwd)" == "/" ]] && echo "Cannot create venv at root" && return 1
  [[ "$(pwd)" != "/" ]] && envdir=$(pwd|sed -e s@/@_@g|cut -c2-)
  [[ "$1" == "-r" ]] && envdir="r-$envdir" # create a venv that will be activated for all subdirectories as well
  if [ ! -e "$PYENV_DIR/${envdir}" ]; then
    echo "Creating python venv for ${envdir}.."
    mkdir "$PYENV_DIR" -p
    python3 -m venv "$PYENV_DIR/${envdir}"
    echo "Activating virtual env ${envdir}"
    export VIRTUAL_ENV_DISABLE_PROMPT=1
    # source "$PYENV_DIR/${envdir}/bin/activate" && [[ ! $PS1 =~ "^$PS1_NEW" ]] && export PS1="$PS1_PRE$PS1_DEFAULT"
    source "$PYENV_DIR/${envdir}/bin/activate" && export PS1="$PS1_PRE$PS1_DEFAULT"
    unset VIRTUAL_ENV_DISABLE_PROMPT 
  else
    echo "A venv for this path already exists"
  fi
}

autoload -U add-zsh-hook
add-zsh-hook chpwd chpwd_activate