#!/bin/bash
# $1 Full path to the installer (unused)
# $2 Location of the Homebrew installation we may need to move into place
# $3 Target install location (unused)
# $4 System root directory (unused)
set -euo pipefail

# disable analytics while installing
export HOMEBREW_NO_ANALYTICS_THIS_RUN=1
export HOMEBREW_NO_ANALYTICS_MESSAGE_OUTPUT=1

# verify the installation exists
# default to /opt/homebrew to make development/testing easier
homebrew_directory="${2:-/opt/homebrew}"
if [[ ! -d "${homebrew_directory:?}" ]]
then
  echo "No directory at ${homebrew_directory}!" >&2
  exit 1
fi

# add Git to path
export PATH="/Library/Developer/CommandLineTools/usr/bin:/Applications/Xcode.app/Contents/Developer/usr/bin:${PATH}"

# avoid writing to user's global config file by overriding HOME
# https://git-scm.com/docs/git-config#SCOPES
unset XDG_CONFIG_HOME
export HOME="${homebrew_directory}"

git_no_hooks() {
  git -c core.hooksPath=/dev/null "$@"
}

# reset Git repository
cd "${homebrew_directory}"
rm -rf "${homebrew_directory}/.git/hooks"
git config --global --add safe.directory "${homebrew_directory}"
latest_tag="$(git_no_hooks -C "${homebrew_directory}" tag --list --sort="-version:refname" | head -n1)"
git_no_hooks -C "${homebrew_directory}" checkout --force -B stable
git_no_hooks -C "${homebrew_directory}" reset --hard "${latest_tag}"
git_no_hooks -C "${homebrew_directory}" clean -f -d
rm -f "${homebrew_directory}/.gitconfig"

# move to /usr/local if on x86_64
if [[ $(uname -m) == "x86_64" ]]
then
  if [[ -f "/usr/local/bin/brew" && -d "/usr/local/Homebrew" ]]
  then
    cp -pRL "${homebrew_directory}/.git" "/usr/local/Homebrew/"
    mv "${homebrew_directory}/cache_api" "/usr/local/Homebrew/"

    export HOME="/usr/local/Homebrew"
    rm -rf "/usr/local/Homebrew/.git/hooks"
    git config --global --add safe.directory "/usr/local/Homebrew"
    git_no_hooks -C "/usr/local/Homebrew" checkout --force -B stable
    git_no_hooks -C "/usr/local/Homebrew" reset --hard
    git_no_hooks -C "/usr/local/Homebrew" clean -f -d
    rm -f "/usr/local/Homebrew/.gitconfig"
  else
    mkdir -vp /usr/local/bin
    mv "${homebrew_directory}" "/usr/local/Homebrew/"

    # create symlink to /usr/local/bin/brew
    ln -svf "../Homebrew/bin/brew" "/usr/local/bin/brew"
  fi

  rm -rf "${homebrew_directory}"
  homebrew_directory="/usr/local/Homebrew"
  cd /usr/local
fi

# create missing directories
mkdir -vp Caskroom Cellar Frameworks etc include lib opt sbin share var/homebrew/linked

# optionally define an install user at /var/tmp/.homebrew_pkg_user.plist
homebrew_pkg_user_plist="/var/tmp/.homebrew_pkg_user.plist"
if [[ -f "${homebrew_pkg_user_plist}" ]] && [[ -n $(defaults read "${homebrew_pkg_user_plist}" HOMEBREW_PKG_USER) ]]
then
  homebrew_pkg_user=$(defaults read /var/tmp/.homebrew_pkg_user HOMEBREW_PKG_USER)
# otherwise, get valid logged in user
else
  homebrew_pkg_user=$(echo "show State:/Users/ConsoleUser" | scutil | awk '/Name :/ { print $3 }')
fi

# set permissions
chmod ug=rwx Caskroom Cellar Frameworks bin etc include lib opt sbin share var var/homebrew var/homebrew/linked
if [[ "${homebrew_directory}" == "/usr/local/Homebrew" ]]
then
  chown -h "${homebrew_pkg_user}:admin" bin bin/brew etc include lib opt sbin share var
  chown -h -R "${homebrew_pkg_user}:admin" Caskroom Cellar Frameworks Homebrew var/homebrew
  chown -h -R "${homebrew_pkg_user}" etc include share var
else
  chown -R "${homebrew_pkg_user}:admin" .
fi

# move API cache to ~/Library/Caches/Homebrew
user_home_dir=$(dscl . read /Users/"${homebrew_pkg_user}" NFSHomeDirectory | awk '{ print $2 }')
user_cache_dir="${user_home_dir}/Library/Caches/Homebrew"
user_api_cache_dir="${user_cache_dir}/api"
mkdir -vp "${user_api_cache_dir}"
mv -v "${homebrew_directory}/cache_api/"* "${user_api_cache_dir}"
chown -R "${homebrew_pkg_user}:staff" "${user_cache_dir}"
rm -vrf "${homebrew_directory}/cache_api"

# create paths.d file for /opt/homebrew installs
# (/usr/local/bin is already in the PATH)
if [[ -d "/etc/paths.d" && "${homebrew_directory}" == "/opt/homebrew" ]]
then
  mkdir -vp /etc/paths.d
  echo "/opt/homebrew/bin" >/etc/paths.d/homebrew
  chown root:wheel /etc/paths.d/homebrew
fi