#!/bin/bash
set +o posix

quiet_cd() {
  cd "$@" >/dev/null
}

symlink_target_directory() {
  local target="$(readlink "$1")"
  local target_dirname="$(dirname "$target")"
  local directory="$2"
  quiet_cd "$directory" && quiet_cd "$target_dirname" && pwd -P
}

BREW_FILE_DIRECTORY="$(quiet_cd "${0%/*}/" && pwd -P)"
HOMEBREW_BREW_FILE="${BREW_FILE_DIRECTORY%/}/${0##*/}"
HOMEBREW_PREFIX="${HOMEBREW_BREW_FILE%/*/*}"

# Default to / prefix if unset or the bin/brew file.
if [[ -z "$HOMEBREW_PREFIX" || "$HOMEBREW_PREFIX" = "$HOMEBREW_BREW_FILE" ]]
then
  HOMEBREW_PREFIX="/"
fi

HOMEBREW_REPOSITORY="$HOMEBREW_PREFIX"

# Resolve the bin/brew symlink to find Homebrew's repository
if [[ -L "$HOMEBREW_BREW_FILE" ]]
then
  BREW_FILE_DIRECTORY="$(symlink_target_directory "$HOMEBREW_BREW_FILE" "$BREW_FILE_DIRECTORY")"
  HOMEBREW_REPOSITORY="${BREW_FILE_DIRECTORY%/*}"
fi

# Try to find a /usr/local HOMEBREW_PREFIX where possible (for bottles)
if [[ -L "/usr/local/bin/brew" ]]
then
  USR_LOCAL_BREW_FILE_DIRECTORY="$(symlink_target_directory "/usr/local/bin/brew" "/usr/local/bin")"
  USR_LOCAL_HOMEBREW_REPOSITORY="${USR_LOCAL_BREW_FILE_DIRECTORY%/*}"
  if [[ "$HOMEBREW_REPOSITORY" = "$USR_LOCAL_HOMEBREW_REPOSITORY" ]]
  then
    HOMEBREW_PREFIX="/usr/local"
  fi
fi

HOMEBREW_LIBRARY="$HOMEBREW_REPOSITORY/Library"

source "$HOMEBREW_LIBRARY/Homebrew/brew.sh"