#!/usr/bin/env miaou-bash

# CONSTANTS

[[ ! -v MIAOU_BASH_DIR ]] && readonly MIAOU_BASH_DIR=/opt/miaou-bash && export MIAOU_BASH_DIR

# functions

function usage {
  echo "usage: $(basename "$0") <packages...>"
  echo 'idempotent package installation : update if necessary, install only if not yet done'
}

function debian_update_repo {
  if [ "$(date --date='-12 hours' +%s)" -gt "$(date -d "$(stat -c %y /var/lib/apt/lists/partial)" +%s)" ]; then
    echo "updating repositoring..."
    apt-get update
  fi
}

function debian_add {
  debian_update_repo
  declare -a wanted=("$@")
  declare -a unrecognized=()
  declare -a missing=()
  mapfile -t queries < <(dpkg-query -W -f='${Package}: ${Status}\n' "${wanted[@]}" 2>&1 || true)

  local unrecognized_regex='^dpkg-query: no packages found matching (.*)$'
  local missing_regex='(.*): .* not-installed$'
  for query in "${queries[@]}"; do
    if [[ "$query" =~ $unrecognized_regex ]]; then
      unrecognized+=("${BASH_REMATCH[1]}")
    elif [[ "$query" =~ $missing_regex ]]; then
      missing+=("${BASH_REMATCH[1]}")
    fi
  done

  if [[ ${#unrecognized[@]} -gt 0 ]]; then
    >&2 echo "$(basename "$0") error: unrecognized packages: ${unrecognized[*]}" && return 2
  elif [[ "${#missing[@]}" -gt 0 ]]; then
    echo installing packages: "${missing[@]}"
    apt-get install -y "${missing[@]}"
  fi
}

function arch_add {
  pacman -Syyu --noconfirm
  for i in "$@"; do
    if ! pacman -Ql "$i" &>/dev/null; then
      pacman -S --noconfirm "$i"
    elif [ -n "${VERBOSE+x}" ] && $VERBOSE; then
      echo "pacman package <$i> already installed!"
    fi
  done
}

# MAIN

[ "$UID" -ne 0 ] && echo 'root privilege required' && exit 2
[[ $# -lt 1 ]] && usage && builtin exit 1

source "$MIAOU_BASH_DIR"/lib/functions.bash
DISTRO_LIKE=$(get_distro_like)
case "$DISTRO_LIKE" in
debian) debian_add "$@" ;;
arch) arch_add "$@" ;;
esac