#!/usr/bin/env bash
#
# Summary: List all Python virtualenvs found in `$PYENV_ROOT/versions/*'.
# Usage: pyenv virtualenvs [--bare] [--skip-aliases] [--only-aliases]
#
# List all virtualenvs found in `$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
    echo --only-aliases
    exit ;;
  --bare ) bare=1 ;;
  --skip-aliases ) skip_aliases=1 ;;
  --only-aliases ) only_aliases=1 ;;
  * )
    pyenv-help --usage virtualenvs >&2
    exit 1
    ;;
  esac
done

versions_dir="${PYENV_ROOT}/versions"

if [[ ${BASH_VERSINFO[0]} -gt 3 ]]; then
  declare -A current_versions
else
  current_versions=()
fi
if [ -n "$bare" ]; then
  include_system=""
else
  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"
  include_system="1"
fi

num_versions=0

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
    # Only resolve the link itself for printing, do not resolve further.
    # Doing otherwise would misinform the user of what the link contains.
    version_repr="$version --> $(readlink "$path")"
  else
    version_repr="$version"
  fi
  if [[ ${BASH_VERSINFO[0]} -ge 4 && ${current_versions["$1"]} ]]; then
    echo "${hit_prefix}${version_repr} (set by $(pyenv-version-origin))"
  elif [[ ${BASH_VERSINFO[0]} -le 3 ]] && exists "$1" "${current_versions[@]}"; then
    echo "${hit_prefix}${version_repr} (set by $(pyenv-version-origin))"
  else
    echo "${miss_prefix}${version_repr}"
  fi
  num_versions=$((num_versions + 1))
}

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

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

if [ -z "$skip_aliases" ]; then
  for env_path in "${version_dir_entries[@]}"; do
    if [ -d "${env_path}" ] && [ -L "${env_path}" ]; then
      print_version "${env_path#"${PYENV_ROOT}"/versions/}" "${env_path}"
    fi
  done
fi

shopt -u dotglob
shopt -u nullglob

if [ "$num_versions" -eq 0 ] && [ -n "$include_system" ]; then
  echo "Warning: no Python virtualenv detected on the system" >&2
  exit 1
fi