#!/usr/bin/env bash
#
# Summary: Display the full path to an executable
#
# Usage: rbenv which <command>
#
# Displays the full path to the executable that rbenv will invoke when
# you run the given command.

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

# Provide rbenv completions
if [ "$1" = "--complete" ]; then
  exec rbenv-shims --short
fi

remove_from_path() {
  local path_to_remove="$1"
  local path_before
  local result=":${PATH//\~/$HOME}:"
  while [ "$path_before" != "$result" ]; do
    path_before="$result"
    result="${result//:$path_to_remove:/:}"
  done
  result="${result%:}"
  echo "${result#:}"
}

RBENV_COMMAND="$1"

if [ -z "$RBENV_COMMAND" ]; then
  rbenv-help --usage which >&2
  exit 1
fi

RBENV_VERSION="${RBENV_VERSION:-$(rbenv-version-name)}"

if [ "$RBENV_VERSION" = "system" ]; then
  PATH="$(remove_from_path "${RBENV_ROOT}/shims")" \
    RBENV_COMMAND_PATH="$(command -v "$RBENV_COMMAND" || true)"
else
  RBENV_COMMAND_PATH="${RBENV_ROOT}/versions/${RBENV_VERSION}/bin/${RBENV_COMMAND}"
  if [ ! -x "$RBENV_COMMAND_PATH" ]; then
    # discover user-install'ed gem executables
    if [ -n "$GEM_HOME" ]; then
      user_install_path="${GEM_HOME}/bin/${RBENV_COMMAND}"
    else
      # FIXME: guessing this path is very fragile and works only for C Ruby
      user_install_path="${HOME}/.gem/ruby/${RBENV_VERSION%.*}.0/bin/${RBENV_COMMAND}"
    fi
    [ -x "$user_install_path" ] && RBENV_COMMAND_PATH="$user_install_path"
    unset user_install_path
  fi
fi

OLDIFS="$IFS"
IFS=$'\n' scripts=(`rbenv-hooks which`)
IFS="$OLDIFS"
for script in "${scripts[@]}"; do
  source "$script"
done

if [ -x "$RBENV_COMMAND_PATH" ]; then
  echo "$RBENV_COMMAND_PATH"
elif [ "$RBENV_VERSION" != "system" ] && [ ! -d "${RBENV_ROOT}/versions/${RBENV_VERSION}" ]; then
  echo "rbenv: version \`$RBENV_VERSION' is not installed (set by $(rbenv-version-origin))" >&2
  exit 1
else
  echo "rbenv: $RBENV_COMMAND: command not found" >&2

  versions="$(rbenv-whence "$RBENV_COMMAND" || true)"
  if [ -n "$versions" ]; then
    { echo
      echo "The \`$1' command exists in these Ruby versions:"
      echo "$versions" | sed 's/^/  /g'
      echo
    } >&2
  fi

  exit 127
fi