#!/bin/bash
# =============================================================================
# machine-setup — system configuration
# =============================================================================
#
# Definitions only, like the other lib/ files. Locale, and the system-level
# settings that follow it.

[[ -n "${MACHINE_SETUP_SYSTEM_LOADED:-}" ]] && return 0
MACHINE_SETUP_SYSTEM_LOADED=1

# -----------------------------------------------------------------------------
# Locale
# -----------------------------------------------------------------------------
#
# Two separate facts, and the original only handled one of them:
#
#   what a new login shell is told to use   — LANG in /etc/default/locale
#   whether that locale actually exists     — whether it has been generated
#
# Setting LANG to a locale that was never generated is the state that produces
# "setlocale: LC_ALL: cannot change locale" on every ssh login and every perl
# invocation. Both are checked, so the step can say which one is missing.

# What a new login shell will be handed, or empty if nothing is configured.
locale_current() {
  if [[ -r /etc/default/locale ]]; then
    awk -F= '/^LANG=/ { gsub(/"/, "", $2); print $2 }' /etc/default/locale
  elif [[ -r /etc/locale.conf ]]; then
    awk -F= '/^LANG=/ { gsub(/"/, "", $2); print $2 }' /etc/locale.conf
  fi
}

# Has this locale actually been built?
#
# `locale -a` prints en_US.utf8 where the configuration spells it en_US.UTF-8,
# so both sides are folded to lower case with the dashes removed before
# comparing. A literal match here would report a perfectly good locale missing.
locale_is_generated() {
  local want="${1,,}"
  want="${want//-/}"
  locale -a 2>/dev/null | tr '[:upper:]' '[:lower:]' | tr -d '-' | grep -qx "$want"
}

locale_set() {
  local want="$1"
  local escaped="${want//./\\.}"

  case "$PM" in
    apt)
      # locale-gen comes from the `locales` package, which minimal images and
      # most cloud base images do not ship. Without this the step fails with
      # "locale-gen: command not found" halfway through.
      if ! pkg_is_installed locales; then
        info "     installing locales, which provides locale-gen"
        pkg_install_now locales
      fi

      # Uncomment it if it is there commented out, add it if it is absent.
      # Editing the file rather than passing the name to locale-gen is what makes
      # it survive: a locale generated by argument alone is lost the next time
      # anything regenerates from /etc/locale.gen.
      if grep -qE "^#[[:space:]]*${escaped}[[:space:]]" /etc/locale.gen 2>/dev/null; then
        sed -i "s/^#[[:space:]]*\(${escaped}[[:space:]]\)/\1/" /etc/locale.gen
      elif ! grep -qE "^${escaped}[[:space:]]" /etc/locale.gen 2>/dev/null; then
        # The charset is the part after the dot: en_US.UTF-8 -> UTF-8
        echo "${want} ${want##*.}" >>/etc/locale.gen
      fi

      locale-gen
      update-locale LANG="$want"
      ;;
    pacman)
      if grep -qE "^#[[:space:]]*${escaped}[[:space:]]" /etc/locale.gen 2>/dev/null; then
        sed -i "s/^#[[:space:]]*\(${escaped}[[:space:]]\)/\1/" /etc/locale.gen
      fi
      locale-gen
      echo "LANG=${want}" >/etc/locale.conf
      ;;
    dnf)
      # No locale.gen here — the locales come prebuilt in langpack packages.
      pkg_install_now "glibc-langpack-${want%%_*}"
      localectl set-locale "LANG=${want}"
      ;;
    brew)
      warn "macOS has no system locale to set — it is per-user, from the terminal's settings"
      return 1
      ;;
  esac
}