#!/usr/bin/env bash
# Summary: List installed Ruby versions
# Usage: rbenv versions [--bare] [--skip-aliases]
#
# Lists all Ruby versions found in `$RBENV_ROOT/versions/*'.

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

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

versions_dir="${RBENV_ROOT}/versions"

if ! enable -f "${BASH_SOURCE%/*}"/rbenv-realpath.dylib realpath 2>/dev/null; then
  if [ -n "$RBENV_NATIVE_EXT" ]; then
    echo "rbenv: failed to load \`realpath' builtin" >&2
    exit 1
  fi

  READLINK=$(type -p greadlink readlink 2>/dev/null | head -n1)
  if [ -z "$READLINK" ]; then
    echo "rbenv: cannot find readlink - are you missing GNU coreutils?" >&2
    exit 1
  fi

  resolve_link() {
    $READLINK "$1"
  }

  realpath() {
    local cwd="$PWD"
    local path="$1"
    local name

    while [ -n "$path" ]; do
      name="${path##*/}"
      [ "$name" = "$path" ] || cd "${path%/*}"
      path="$(resolve_link "$name" || true)"
    done

    echo "${PWD}/$name"
    cd "$cwd"
  }
fi

if [ -d "$versions_dir" ]; then
  versions_dir="$(realpath "$versions_dir")"
fi

if [ -n "$bare" ]; then
  hit_prefix=""
  miss_prefix=""
  current_version=""
  include_system=""
else
  hit_prefix="* "
  miss_prefix="  "
  current_version="$(rbenv-version-name || true)"
  include_system="1"
fi

num_versions=0

print_version() {
  if [ "$1" == "$current_version" ]; then
    echo "${hit_prefix}$(rbenv-version 2>/dev/null)"
  else
    echo "${miss_prefix}$1"
  fi
  num_versions=$((num_versions + 1))
}

sort_versions() {
  sed 'h; s/[+-]/./g; s/.p\([[:digit:]]\)/.z.\1/; s/$/.z/; G; s/\n/ /' | \
    LC_ALL=C sort -t. -k 1,1 -k 2,2n -k 3,3n -k 4,4n -k 5,5n | awk '{print $2}'
}

# Include "system" in the non-bare output, if it exists
if [ -n "$include_system" ] && RBENV_VERSION=system rbenv-which ruby >/dev/null 2>&1; then
  print_version system
fi

shopt -s nullglob

versions=($(
for path in "$versions_dir"/*; do
  if [ -d "$path" ]; then
    if [ -n "$skip_aliases" ] && [ -L "$path" ]; then
      target="$(realpath "$path")"
      [ "${target%/*}" != "$versions_dir" ] || continue
    fi
    echo "${path##*/}"
  fi
done
))

sorted_versions=($(printf "%s\n" ${versions[@]} | sort_versions))

for version in ${sorted_versions[@]}; do
  print_version $version
done

shopt -u nullglob

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