#!/usr/bin/env bash
#
# Summary: List all Python virtualenvs found in `$PYENV_ROOT/versions/*'.
# Usage: pyenv virtualenvs [--bare] [--skip-aliases]
#
# List all virtualenvs found in `$PYENV_ROOT/versions/*' and its `$PYENV_ROOT/versions/envs/*'.

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

if [[ -z $PYENV_ROOT ]]; then
  PYENV_ROOT="${HOME}/.pyenv"
fi

unset bare
unset skip_aliases
# Provide pyenv completions
for arg; do
  case "$arg" in
  --complete )
    echo --bare
    echo --skip-aliases
    exit ;;
  --bare ) bare=1 ;;
  --skip-aliases ) skip_aliases=1 ;;
  * )
    pyenv-help --usage virtualenvs >&2
    exit 1
    ;;
  esac
done

versions_dir="${PYENV_ROOT}/versions"

if [[ ${BASH_VERSINFO[0]} -gt 3 ]]; then
  declare -A current_versions
else
  current_versions=()
fi
if [[ -z $bare ]]; then
  hit_prefix="* "
  miss_prefix="  "
  OLDIFS="$IFS"
  IFS=:
  if [[ ${BASH_VERSINFO[0]} -gt 3 ]]; then
    for i in $(pyenv-version-name || true); do
      current_versions["$i"]="1"
    done
  else
    read -r -a current_versions <<< "$(pyenv-version-name || true)"
  fi
  IFS="$OLDIFS"
fi

exists() {
  local car="$1"
  local cdar
  shift
  for cdar in "$@"; do
    if [ "${car}" == "${cdar}" ]; then
      return 0
    fi
  done
  return 1
}

print_version() {
  local version="${1:?}"
  if [[ -n $bare ]]; then
    echo "$version"
    return
  fi
  local path="${2:?}"
  if [[ -L "$path" ]]; then
    version_repr="$version --> $(readlink "$path")"
  else
    version_repr="$version (created from $(pyenv-virtualenv-prefix "$version" 2>/dev/null))"
  fi
  if [[ ${BASH_VERSINFO[0]} -gt 3 && ${current_versions["$1"]} ]] || \
     { [[ ${BASH_VERSINFO[0]} -le 3 ]] && exists "$1" "${current_versions[@]}"; }; then
    echo "${hit_prefix}${version_repr} (set by $(pyenv-version-origin))"
  else
    echo "${miss_prefix}${version_repr}"
  fi
}

shopt -s dotglob
shopt -s nullglob
version_dir_entries=("$versions_dir"/*)
venv_dir_entries=("$versions_dir"/*/envs/*)

if sort --version-sort </dev/null >/dev/null 2>&1; then
    # system sort supports version sorting
    OLDIFS="$IFS"
    IFS='||'

    read -r -a version_dir_entries <<< "$(
        printf "%s||" "${version_dir_entries[@]}" |
        sort --version-sort
    )"

    read -r -a venv_dir_entries <<< "$(
        printf "%s||" "${venv_dir_entries[@]}" |
        sort --version-sort
    )"

    IFS="$OLDIFS"
fi

for env_path in "${venv_dir_entries[@]}"; do
  if [[ -d ${env_path} ]]; then
    print_version "${env_path#"${PYENV_ROOT}"/versions/}" "${env_path}"
  fi
done

for env_path in "${version_dir_entries[@]}"; do
  if [[ -d ${env_path} ]]; then
    if [[ -L ${env_path} ]]; then
      if [[ -z $skip_aliases ]]; then
        print_version "${env_path#"${PYENV_ROOT}"/versions/}" "${env_path}"
      fi
    # Mimics the test from pyenv-virtualenv-prefix
    # XXX: refactor itto a shared module ?
    elif [[ -f "${env_path}/bin/activate" ]]; then
      print_version "${env_path#"${PYENV_ROOT}"/versions/}" "${env_path}"
    fi
  fi
done

shopt -u dotglob
shopt -u nullglob