#!/bin/bash
# Copyright 2018 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

### do a system OTA

## usage: fx ota [-h|--help]
##
## Ask the target to do an OTA. The target will use any update server available
## to it to do the update. This requires the target have a update server
## available to it. The 'serve' fx command is typically used to make your
## development host available to the target as an update server.
##
## Arguments:
##   -h|--help    Print out this message.

source "$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"/lib/vars.sh || exit $?
source "$(cd "$(dirname "${BASH_SOURCE[0]}")" >/dev/null 2>&1 && pwd)"/lib/updates.sh || exit $?
fx-config-read

function needs-update {
  local system_image_merkle="${FUCHSIA_BUILD_DIR}"/obj/build/images/system_image.meta/meta.far.merkle
  [[ $(fx-command-run shell cat system/meta) != $(<"${system_image_merkle}") ]]
}

function main {
  fx-standard-switches "$@"
  set -- "${FX_ARGV[@]}"

  check-for-amber-server || return -1

  if needs-update; then
    fx-command-run shell "$@" amberctl system_update || return $?
    fx-command-run shell log_listener --since_now yes --clock Local
  fi
  fx-command-run wait
  if needs-update; then
    fx-error "After update, system appears still out of date."
    return 1
  fi
}

main "$@"