#!/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.

### Run Fuchsia on QEMU in background and runs SSH command after netstack runs.

## Run Fuchsia on QEMU (using standard fx setup) in background and pings the
## target until netstack is up running. If successful, issues the given SSH
## command.
##
## usage: fx net-run [--klog PATH]
##                   [--run RUN_OPTIONS]
##                   [--target TARGET]
##                   [--] SSH_COMMAND
##
##    --klog        Path where to pipe kernel log. Defaults to stdout.
##                  stderr will still be visible.
##    --run         The options to be passed to "fx run". If not set, it will
##                  attempt to load ${FX_NET_RUN_OPTIONS}. Finally, defaults to
##                  "-N -u ${FUCHSIA_DIR}/scripts/start-dhcp-server.sh".
##    --target      IP or hostname to connect to. If not supplied, it will
##                  attempt to guess it from ${FX_NET_RUN_TARGET}.
##
##    SSH_COMMAND   Any other argument will be passed directly to "fx ssh".
##                  If not specified, it will open an interactive SSH session.

source "$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"/lib/vars.sh

# Defaults
# If --run is set, it will overwrite this value
run_options="${FX_NET_RUN_OPTIONS}"
if [[ -z "${run_options}" ]]; then
  run_options="-N -u "${FUCHSIA_DIR}"/scripts/start-dhcp-server.sh"
fi
target="${FX_NET_RUN_TARGET}"

# Flag parsing
while [[ "$1" =~ ^- ]]; do
  case "$1" in
    -h|--help)
      fx-command-help
      exit 0
      ;;
    --run)
      shift
      run_options="$1"
      ;;
    --target)
      shift
      target="$1"
      ;;
    --klog)
      shift
      klog="$1"
      ;;
    --)
      break
      ;;
    *)
      break
  esac
  shift
done

# Error check
if [[ -z "${target}" ]]; then
  echo -e "No target found. Use --target or export \$FX_NET_RUN_TARGET."
  exit 1
fi

# Run fx run in background. If successful, it will be sent to background.
echo "Using \"${run_options}\" to boot Fuchsia."
echo "You might need to run sudo beforehand."
if [[ -z "$klog" ]]; then
  fx-command-run "run" ${run_options} &
else
  # Only pipe stdout
  fx-command-run "run" ${run_options} > "${klog}" &
  echo "Piping Fuchsia output to \"${klog}\"."
fi
fx_pid="$!"

# Wait until netstack is on
ping_count=1
ping_max=120  # 2 Minute
echo "Waiting for device on ${target}."
while true; do
  echo "Ping ${ping_count}/${ping_max}"
  ping -c1 -W1 "${target}" > /dev/null &
  # We wait so we can ctrl-c kill it
  wait "$!"

  # If the ping is successful, we break
  if [[ "$?" -eq 0 ]]; then
    break
  fi

  # Check for exit condition
  ping_count=$(expr "${ping_count}" + 1)
  if [[ "${ping_count}" -gt "${ping_max}" ]]; then
    echo -e "Timed out waiting for Fuchsia. Exiting."
    kill "${fx_pid}"
    exit 1
  fi
done

# Run the SSH command
fx-command-run "ssh" "${target}" "$@"