#!/bin/bash

# Copyright 2012 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

set -e

LOGOUT_MSG="
Name: Please log out to update
Priority: Medium
OnlyAdminUsers: False
DontShowAfterReboot: true
DisplayIf: /opt/google/chrome-remote-desktop/is-remoting-session
Description: Chrome Remote Desktop has been updated. Please save your work and log out in order to apply this update. Your virtual desktop will be restarted automatically.
"

NOTIFIER_DIR="/var/lib/update-notifier/user.d"
VAR_DIR="/var/lib/chrome-remote-desktop"
HASHES_FILE="$VAR_DIR/hashes"
INSTALL_DIR="/opt/google/chrome-remote-desktop"
HOST_PATH="$INSTALL_DIR/chrome-remote-desktop-host"
# Per Debian policy 9.2.1, system usernames should all start with an underscore.
CRD_NETWORK_USER="_crd_network"
CRD_PEER_CONNECTION_USER="_crd_peer_connection"
CRD_CRASHPAD_USER="_crd_crashpad"

kill_processes() {
  # Kill CRD processes except for the service script process. The script process
  # command line conveniently starts with /usr/bin/python3, so the pkill pattern
  # won't kill it. SIGUSR2 is tried first to allow host processes to shut down
  # cleanly after notifying clients. SIGKILL is used as a fallback if they are
  # deadlocked or fail to exit.
  # For the multi-process host, this kills the daemon process and all its
  # children, then the systemd service will relaunch the daemon
  # process, which will recover GDM remote displays created by the previous
  # incarnation.
  # TODO: crbug.com/496325766 - Improve the upgrade experience.
  echo "Killing Chrome Remote Desktop processes so that they can be reloaded (sessions will be unaffected)..."
  pkill -USR2 -f "^$INSTALL_DIR" || true
  # Wait up to 5 seconds for the host processes to shut down cleanly.
  for i in {1..10}; do
    if ! pgrep -f "^$INSTALL_DIR" > /dev/null; then
      return
    fi
    sleep 0.5
  done
  echo "Clean shutdown failed, killing processes..."
  pkill -KILL -f "^$INSTALL_DIR" || true
}

case "$1" in
  "configure")
    echo "Adding users $CRD_NETWORK_USER, $CRD_PEER_CONNECTION_USER, and $CRD_CRASHPAD_USER to allow"
    echo 'Chrome Remote Desktop processes to be run in sandboxed environments.'
    # On Debian 11 or older, usernames with a leading underscore are not allowed
    # unless --allow-bad-names or --force-badname is set. --allow-bad-names is
    # only available in newer versions (>= 3.134) of adduser.
    ADDUSER_OPTS="--system"
    ADDUSER_VERSION=$(dpkg-query -W -f='${Version}' adduser)
    if dpkg --compare-versions "$ADDUSER_VERSION" ge "3.134"; then
      ADDUSER_OPTS="$ADDUSER_OPTS --allow-bad-names"
    else
      ADDUSER_OPTS="$ADDUSER_OPTS --force-badname"
    fi
    adduser $ADDUSER_OPTS "$CRD_NETWORK_USER"
    adduser $ADDUSER_OPTS "$CRD_PEER_CONNECTION_USER"
    adduser $ADDUSER_OPTS "$CRD_CRASHPAD_USER"

    # Clean up legacy per-process Crashpad database directories.
    # Note: The new unified crashpad database directory is created and managed
    # by the daemon process when setting up crashpad.
    rm -rf "$VAR_DIR"/crashpad.{daemon,network,peer_connection}

    kill_processes

    # If any files have changed that require the user to restart their virtual
    # desktops (eg, the wrapper script itself) then notify them but don't do
    # anything that would result in them losing state.
    if [ -f "$HASHES_FILE" ]; then
      if [ -d "$NOTIFIER_DIR" ]; then
        if ! md5sum --status -c "$HASHES_FILE" 2>/dev/null; then
          echo "Sending logout notification messages to virtual desktops."
          echo "$LOGOUT_MSG" > "$NOTIFIER_DIR/chrome-remote-desktop-logout"
        fi
      fi
      rm "$HASHES_FILE"
      rmdir --ignore-fail-on-non-empty "$VAR_DIR"
    fi
    ;;

  "triggered")
    echo "Responding to dpkg trigger."
    kill_processes
    ;;
esac

# Run the cron job immediately to perform repository configuration.
nohup sh /etc/cron.daily/chrome-remote-desktop > /dev/null 2>&1 &

#DEBHELPER#