update.sh

#!/usr/bin/env bash
set -Eeuo pipefail

SCRIPT_DIR="$(cd -- "$(dirname -- "${BASH_SOURCE[0]}")" && pwd)"
source "$SCRIPT_DIR/lib/common.sh"
source "$SCRIPT_DIR/lib/distro.sh"
source "$SCRIPT_DIR/lib/network.sh"
source "$SCRIPT_DIR/lib/build.sh"

APPLY=0
REQUESTED_TAG=""

while (($#)); do
  case "$1" in
    --apply) APPLY=1 ;;
    --tag)
      shift
      (($#)) || die "--tag requires a value."
      REQUESTED_TAG="$1"
      ;;
    -h|--help)
      printf 'Usage: ./update.sh [--apply] [--tag TAG]\n'
      exit 0
      ;;
    *) die "Unknown option: $1" ;;
  esac
  shift
done

require_linux
load_state
LATEST_TAG="$(list_upstream_tags | head -n1)"
[[ -n "$LATEST_TAG" ]] || die "No upstream Bridge release tags were found."
TARGET_TAG="${REQUESTED_TAG:-$LATEST_TAG}"
list_upstream_tags | grep -Fxq "$TARGET_TAG" || die "Unknown upstream tag: $TARGET_TAG"

printf 'Installed tag: %s\nTarget tag   : %s\nNetwork mode : %s\nBind host    : %s\n' \
  "$BRIDGE_TAG" "$TARGET_TAG" "$NETWORK_MODE" "$BIND_HOST"

if [[ "$TARGET_TAG" == "$BRIDGE_TAG" ]]; then
  log "The selected tag is already installed."
  exit 0
fi

if (( ! APPLY )); then
  printf '\nNo changes were made. Run sudo ./update.sh --apply to update.\n'
  exit 0
fi

require_root
require_systemd
detect_distro
confirm_exact "UPDATE" "The selected tag will be built and replace the active Bridge binary."

OLD_TARGET="$(readlink -f "$ACTIVE_LINK")"
OLD_TAG="$BRIDGE_TAG"
OLD_VERSION="$BRIDGE_VERSION"
BRIDGE_TAG="$TARGET_TAG"
BRIDGE_VERSION="${BRIDGE_TAG#v}"
BRIDGE_VERSION="${BRIDGE_VERSION#br-}"

install_dependencies
prepare_source_tree "$BRIDGE_TAG"
ensure_go_toolchain
build_bridge
write_state

if systemctl is-enabled --quiet "$SERVICE_NAME"; then
  systemctl restart "$SERVICE_NAME"
  sleep 3
  if ! systemctl is-active --quiet "$SERVICE_NAME"; then
    warn "The updated service failed. Rolling back."
    ln -sfn "$OLD_TARGET" "$ACTIVE_LINK"
    BRIDGE_TAG="$OLD_TAG"
    BRIDGE_VERSION="$OLD_VERSION"
    write_state
    systemctl restart "$SERVICE_NAME" || true
    die "Update failed; the previous binary was restored."
  fi
fi

log "Updated Proton Bridge to $BRIDGE_TAG."