#!/bin/bash
# Copyright 2017 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.

#### CATEGORY=Device management
### reboot a target fuchsia system

## usage: fx reboot [-r|--recovery] [-b|--bootloader]
##   -r|--recovery   Reboot into recovery image
##   -b|--bootloader Reboot into bootloader
##
## This will reboot the device specified with `fx set-device`; otherwise
## one of the devices on the link-local network.

set -e

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

function usage() {
    fx-command-help
}

reboot_type="reboot"
while [[ "$1" =~ ^- ]]; do
  case "$1" in
  -h|--help)
    usage
    exit 0
    ;;
  -r|--recovery)
    reboot_type="reboot-recovery"
    ;;
  -b|--bootloader)
    reboot_type="reboot-bootloader"
    ;;
  *)
    break
  esac
  shift
done

if [[ $# -gt 1 ]]; then
  usage
  exit 1
fi

device="$(get-device-name)" || exit $?

if [[ -z "$(get-fuchsia-device-addr)" ]]; then
  echo >&2 "Could not find ${device} in Fuchsia, attempting to reboot using netboot (Zedboot)"
  exec "${FUCHSIA_BUILD_DIR}/host-tools/netruncmd" "--nowait" "${device}" "dm ${reboot_type}"
fi

echo "Rebooting ${device}..."

# Check that the device is reachable over SSH, otherwise let the user know.
# This establishes a ControlMaster.
monotime=$(fx-command-run shell clock --monotonic)
if [[ $? -ne 0 ]]; then
  fx-error "Could not reach ${device} over SSH"
  exit 1
fi

# The following command reboots the device using `dm` over SSH. This
# command can often fail since the connection races with the device
# shutdown. To ensure we correctly shelled into the device and
# issued a reboot, we use the loop following this line to verify.
fx-command-run shell "dm \"${reboot_type}\" &" || true

# Wait for the SSH connection to go down. As we use ControlMaster, we can
# observe this using the control master check.
i=0
while fx-command-run shell -O check > /dev/null 2>&1; do
  if [[ "$monotime" -gt $(fx-command-run shell clock --monotonic) ]]; then
    # If we get here, then we raced between reboot and check, the device
    # rebooted so fast that someone reconnected our SSH ControlMaster before we
    # observed it going down (this generally only happens if the `dm` command
    # is backgrounded before being issued and another command happens to shell
    # into the device (usually package serving causes this)).
    exit 0
  fi

  sleep 0.5
  if [[ "$((i++))" -gt "10" ]]; then
    fx-error "SSH still connected after $((i/2))s, reboot may have failed"
    exit 1
  fi
done