miaou-bash/lib/functions.bash

## library of useful functions, usually prefixed with '_'

function sudo_root {
  [[ "$UID" -ne 0 ]] && sudo -vp 'SUDO privilege required: '
  true
}

## ASSERT Functions

function assert_root {
  [[ "$UID" -ne 0 ]] && echo 'root privilege required' && return 1
  true
}

function assert_container {
  [[ $(systemd-detect-virt -c) == lxc ]]
}

function fetch_mode {
  [[ -v MIAOU_BASH_MODE ]] && return
  MIAOU_BASH_MODE_OWNER=$(stat -c '%U' "$MIAOU_BASH_DIR"/)
  if [[ -L "$MIAOU_BASH_DIR" ]]; then
    MIAOU_BASH_MODE='development'
  elif [[ "$MIAOU_BASH_MODE_OWNER" == root ]]; then
    MIAOU_BASH_MODE='system'
  elif [[ "$MIAOU_BASH_MODE_OWNER" == nobody ]]; then
    MIAOU_BASH_MODE='hosted'
  else
    >&2 echo "MIAOU ERROR: unknown mode: $(realpath "$MIAOU_BASH_DIR") owned by: $MIAOU_BASH_MODE_OWNER" &&
      return 3
  fi
}

function assert_system_mode {
  [[ -L "$MIAOU_BASH_DIR" ]] &&
    >&2 echo "ERROR: development mode: $(realpath "$MIAOU_BASH_DIR")" &&
    return 3

  assert_container && [[ $(stat -c '%U' "$MIAOU_BASH_DIR") == 'nobody' ]] &&
    >&2 echo "ERROR: hosted mode" &&
    return 4

  true
}
## ===============
## ARRAY Functions
## ===============

function _array_contains {
  local -n array=$1
  local element=$2
  for item in "${array[@]}"; do
    [[ "$item" == "$element" ]] && return 0
  done
  return 1
}

function _array_intersect {
  local -n arr1=$1
  local -n arr2=$2
  local -n result=$3

  declare -A include
  for item in "${arr2[@]}"; do include["$item"]=1; done

  result=()
  for item in "${arr1[@]}"; do [[ -n ${include["$item"]} ]] && result+=("$item"); done
}

function _array_subtract {
  local -n arr1 arr2 result
  arr1=$1   # First array
  arr2=$2   # Array to subtract
  result=$3 # Output array

  [[ ${#arr2[@]} == 0 ]] && result=("${arr1[@]}") && return

  declare -A exclude
  for item in "${arr2[@]}"; do exclude["$item"]=1; done

  for item in "${arr1[@]}"; do [[ -z ${exclude["$item"]} ]] && result+=("$item"); done
}

## ==============
## TEXT Functions
## ==============

function _pluralize_simple {
  echo -n "$1 "
  [[ $1 -eq 1 || $1 -eq -1 ]] && echo "${2}" || echo "${2}s"
}

## ==============
## READ Functions
## ==============

function fetch_distro_like {
  if grep -qE '^ID=debian|^ID_LIKE=debian' /etc/os-release; then
    DISTRO_LIKE=debian
  elif grep -qE '^ID=arch|^ID_LIKE=arch' /etc/os-release; then
    DISTRO_LIKE=arch
  else
    local unsupported_distro
    unsupported_distro=$(grep ^ID= /etc/os-release | cut -d= -f2)
    >&2 echo -n "MIAOU ERROR: unsupported distro: $unsupported_distro"
    return 99
  fi
  export DISTRO_LIKE
}

function _confirm_destructive {
  local message="${1:-This cannot be undone!}"
  echo "⚠️ WARNING: $message"
  read -rp "Type YES to confirm: " response
  case "$response" in
  [yY][eE][sS] | [yY]) return 0 ;;
  *) echo "canceled!" && return 1 ;;
  esac
}

## =================
## OPTIONS Functions
## =================

function _flatten_short_options {
  local -n args=$1
  local result=()
  for word in "${args[@]}"; do
    [[ $word == -- ]] && break
    if [[ $word =~ ^-[a-z][a-z] ]]; then
      word=${word:1}
      for ((i = 0; i < ${#word}; i++)); do result+=("-${word:i:1}"); done
    else
      result+=("$word")
    fi
  done
  args=("${result[@]}")
}

# DISTRO

function get_distro_like {
  mapfile -t release </etc/os-release
  for line in "${release[@]}"; do
    case "$line" in
    ID=debian | ID_LIKE=debian)
      echo debian
      return
      ;;
    ID=arch | ID_LIKE=arch)
      echo arch
      return
      ;;
    esac
  done
  return 1
}

## FIXME: Deprecated -> to remove
## ==============

##
# return 0 (true) if array (passed by name) contains element
# usage:
#   ARRAY=( a b c )
#   containsElement ARRAY 'a' => 0
function containsElement {
  isArray "$1" || (echo >&2 "ERROR: <$1> not an array!" && return 2)
  array_inter="$1[@]"
  array=("${!array_inter}")
  for i in "${array[@]}"; do [[ "$i" == "$2" ]] && return 0; done
  return 1
}

## return 0 (true) if arg1 (passed by name) is an array
function isArray {
  [[ "$(declare -p "$1" 2>/dev/null)" =~ "declare -a" ]] || return 1
}

function isDebian {
  grep -q ^ID=debian /etc/os-release
}

function isArch {
  grep -q ^ID=arch /etc/os-release
}

function os-release {
  grep ^ID= /etc/os-release | cut -d '=' -f2
}

function askConfirmation {
  case "$1" in
  y | Y | yes | YES)
    QUESTION="(Y/n)?"
    DEFAULT=0
    ;;
  *)
    QUESTION="(y/N)?"
    DEFAULT=1
    ;;
  esac
  read -rp "$QUESTION : " choice
  case "$choice" in
  y | Y | yes | YES) return 0 ;; #true
  n | no | N | NO) return 1 ;;   #false
  *) return $DEFAULT ;;
  esac
}