#!/bin/bash -p

# omarchy:summary=Overwrite the package configuration for /etc/pacman with the Omarchy default of using its dedicated mirrors and repositories, then update all packages.
# omarchy:requires-sudo=true

if [[ $- != *p* ]]; then
  echo "Refusing an unsafe Bash startup for pacman refresh." >&2
  exit 126
fi

require_privileged_bash_startup() {
  [[ $- == *p* ]] || return 1
  /usr/bin/env -i /usr/bin/bash -p -c '
    [[ $1 =~ ^[1-9][0-9]*$ ]] || exit 1
    mapfile -d "" -t argv <"/proc/$1/cmdline" || exit 1
    executable=$(/usr/bin/readlink -e -- "/proc/$1/exe") || exit 1
    [[ $executable == /usr/bin/bash ]]
    [[ ${argv[0]:-} == /bin/bash || ${argv[0]:-} == /usr/bin/bash ]]
    [[ ${argv[1]:-} == -p ]]
  ' omarchy-bash-startup "$$"
}
if ! require_privileged_bash_startup; then
  echo "Refusing an unsafe Bash startup for pacman refresh." >&2
  exit 126
fi
unset -f require_privileged_bash_startup

set -e

sanitize_bash_startup_environment() {
  local environment_entry environment_name
  local needs_reexec=0
  local -a environment_unsets=(-u BASH_ENV -u ENV)

  [[ -z ${BASH_ENV+x} && -z ${ENV+x} ]] || needs_reexec=1
  while IFS= read -r -d '' environment_entry; do
    environment_name="${environment_entry%%=*}"
    if [[ $environment_name == BASH_FUNC_*%% ]]; then
      environment_unsets+=(-u "$environment_name")
      needs_reexec=1
    fi
  done < <(/usr/bin/env -0)

  if (( needs_reexec )); then
    exec /usr/bin/env "${environment_unsets[@]}" /usr/bin/bash -p "$0" "$@"
  fi
}
sanitize_bash_startup_environment "$@"
unset -f sanitize_bash_startup_environment

usage() {
  echo "Usage: omarchy-refresh-pacman [stable|rc|edge]" >&2
}

# Composite commands can postpone the legacy user hook until their own final
# privilege boundary. The two internal modes are deliberately paired: a caller
# that defers must invoke --run-deferred-hook exactly once after all of its
# sudo-capable work has finished.
channel=stable
hook_mode=normal
case "$#:$1:${2:-}" in
  0::)
    ;;
  1:stable: | 1:rc: | 1:edge:)
    channel="$1"
    ;;
  1:--run-deferred-hook:)
    hook_mode=run-deferred
    ;;
  2:stable:--defer-hook | 2:rc:--defer-hook | 2:edge:--defer-hook)
    channel="$1"
    hook_mode=defer
    ;;
  *)
    usage
    exit 2
    ;;
esac

trusted_directory_chain() {
  local current="$1" allow_current_user="$2" canonical owner mode current_uid
  current_uid=$(/usr/bin/id -u) || return 1

  while :; do
    [[ -d $current && ! -L $current ]] || return 1
    canonical=$(/usr/bin/realpath -e -- "$current") || return 1
    [[ $canonical == "$current" ]] || return 1
    [[ $current == / ]] && break
    read -r owner mode < <(/usr/bin/stat -Lc '%u %a' -- "$current") || return 1
    if [[ $owner != 0 ]] && ! { [[ $allow_current_user == "true" && $owner == "$current_uid" ]]; }; then
      return 1
    fi
    (( (8#$mode & 0022) == 0 )) || return 1
    current=${current%/*}
    [[ -n $current ]] || current=/
  done
}

trusted_omarchy_source_root() {
  local config=/etc/omarchy.conf default_root=/usr/share/omarchy configured_root="" canonical=""
  local owner="" mode="" links="" size="" line="" encoded="" decoded="" character=""
  local index=0 escaped=0 lines=()

  if [[ ! -e $config && ! -L $config ]]; then
    configured_root="$default_root"
  else
    [[ -f $config && ! -L $config ]] || return 1
    canonical=$(/usr/bin/realpath -e -- "$config") || return 1
    [[ $canonical == "$config" ]] || return 1
    read -r owner mode links size < <(/usr/bin/stat -Lc '%u %a %h %s' -- "$config") || return 1
    [[ $owner == "0" && $links == "1" ]] || return 1
    (( (8#$mode & 0022) == 0 && size > 0 && size <= 4096 )) || return 1
    trusted_directory_chain /etc false || return 1
    mapfile -t lines <"$config" || return 1
    (( ${#lines[@]} == 1 )) || return 1
    line="${lines[0]}"
    [[ $line == 'export OMARCHY_PATH="'*'"' ]] || return 1
    encoded="${line#'export OMARCHY_PATH="'}"
    encoded="${encoded%'"'}"
    for (( index = 0; index < ${#encoded}; index++ )); do
      character="${encoded:index:1}"
      if (( escaped )); then
        case "$character" in
          '\' | '"' | '$' | '`') decoded+="$character" ;;
          *) return 1 ;;
        esac
        escaped=0
      elif [[ $character == '\' ]]; then
        escaped=1
      elif [[ $character == '"' ]]; then
        return 1
      else
        decoded+="$character"
      fi
    done
    (( escaped == 0 )) || return 1
    configured_root="$decoded"
  fi

  [[ -d $configured_root && ! -L $configured_root ]] || return 1
  canonical=$(/usr/bin/realpath -e -- "$configured_root") || return 1
  [[ $canonical == "$configured_root" ]] || return 1
  if [[ $configured_root == "$default_root" ]]; then
    trusted_directory_chain "$configured_root" false || return 1
  else
    trusted_directory_chain "$configured_root" true || return 1
  fi
  printf '%s\n' "$configured_root"
}

trusted_omarchy_source_file() {
  local relative="$1" source="$OMARCHY_PATH/$1" canonical owner mode links directory current_uid
  current_uid=$(/usr/bin/id -u) || return 1
  [[ $relative != /* && $relative != ../* && $relative != */../* && $relative != */.. ]] || return 1
  [[ -f $source && ! -L $source ]] || return 1
  canonical=$(/usr/bin/realpath -e -- "$source") || return 1
  [[ $canonical == "$source" && $canonical == "$OMARCHY_PATH/"* ]] || return 1
  read -r owner mode links < <(/usr/bin/stat -Lc '%u %a %h' -- "$source") || return 1
  [[ $links == 1 ]] && (( (8#$mode & 0022) == 0 )) || return 1
  if [[ $OMARCHY_PATH == /usr/share/omarchy ]]; then
    [[ $owner == 0 ]] || return 1
  else
    [[ $owner == 0 || $owner == "$current_uid" ]] || return 1
  fi

  directory=${source%/*}
  while [[ $directory == "$OMARCHY_PATH" || $directory == "$OMARCHY_PATH/"* ]]; do
    [[ -d $directory && ! -L $directory ]] || return 1
    canonical=$(/usr/bin/realpath -e -- "$directory") || return 1
    [[ $canonical == "$directory" ]] || return 1
    read -r owner mode < <(/usr/bin/stat -Lc '%u %a' -- "$directory") || return 1
    (( (8#$mode & 0022) == 0 )) || return 1
    if [[ $OMARCHY_PATH == /usr/share/omarchy ]]; then
      [[ $owner == 0 ]] || return 1
    else
      [[ $owner == 0 || $owner == "$current_uid" ]] || return 1
    fi
    [[ $directory == "$OMARCHY_PATH" ]] && break
    directory=${directory%/*}
  done
  printf '%s\n' "$source"
}

if ! OMARCHY_PATH=$(trusted_omarchy_source_root); then
  echo "Refusing to refresh pacman from an untrusted Omarchy source root." >&2
  exit 1
fi
export OMARCHY_PATH
user_path="${PATH:-/usr/bin:/bin}"
PATH="$OMARCHY_PATH/bin:/usr/bin:/usr/sbin:/bin:/sbin"
export PATH

as_root() {
  if ((EUID == 0)); then
    "$@"
  elif [[ ${OMARCHY_SUDO_NO_UPDATE:-0} == 1 ]]; then
    /usr/bin/sudo -N -- "$@"
  else
    /usr/bin/sudo -- "$@"
  fi
}

cleanup_sudo_credentials() {
  /usr/bin/sudo -k || true
}

trap cleanup_sudo_credentials EXIT

if [[ $hook_mode == "run-deferred" ]]; then
  /usr/bin/sudo -k || exit 1
  PATH="$user_path" "$OMARCHY_PATH/bin/omarchy-hook" pre-refresh-pacman
  exit
fi

pacman_source=$(trusted_omarchy_source_file "default/pacman/pacman-$channel.conf") || {
  echo "Refusing an untrusted pacman configuration source." >&2
  exit 1
}
mirror_source=$(trusted_omarchy_source_file "default/pacman/mirrorlist-$channel") || {
  echo "Refusing an untrusted pacman mirror source." >&2
  exit 1
}

as_root /usr/bin/cp -f -- /etc/pacman.conf /etc/pacman.conf.bak
as_root /usr/bin/cp -f -- /etc/pacman.d/mirrorlist /etc/pacman.d/mirrorlist.bak

echo "Setting channel to $channel"
echo

# The unprivileged shell opens the authorized source. Root consumes only the
# inherited descriptor, never a caller-writable development-checkout pathname.
as_root /usr/bin/install -T -o root -g root -m 0644 /dev/stdin /etc/pacman.conf <"$pacman_source"
as_root /usr/bin/install -T -o root -g root -m 0644 /dev/stdin /etc/pacman.d/mirrorlist <"$mirror_source"

# Reset all package DBs and then update.
as_root /usr/bin/env OMARCHY_UPDATE_PACMAN=1 /usr/bin/pacman -Syyuu --noconfirm

# This legacy hook used to run before pacman. Executable user code cannot
# safely precede a later sudo authentication: a child can wait for the new
# timestamp even if the parent invalidates around the hook. Keep the hook, but
# run it only after every privileged refresh step and with a cold credential.
if [[ $hook_mode == "normal" ]]; then
  /usr/bin/sudo -k || exit 1
  PATH="$user_path" "$OMARCHY_PATH/bin/omarchy-hook" pre-refresh-pacman
fi