#!/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.

### set the default device to interact with

## usage: fx set-device [<device-name>]
##
## fx set-device is used to specify the default device to target for various
## fx commands, such as serve, syslog, and so on.
## A device is set within the scope of a build directory (i.e. out/arm64 may
## have a different pair set than out/x64).
##
## If no device name is given, set-device will attempt to discover devices. If
## one device is found, that device is set as the default for the current build
## directory. If more than one device is found, the user must select one and
## provide it to a subsequent invocation of the command.
##
## To unset, use `fx unset-device`.

set -e

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

function select_device() {
  IFS=$'\n' read -rd '' -a devices <<<"$1"
  select choice in "${devices[@]}"; do
    echo "${devices[$((REPLY-1))]}"
    break
  done
}

device="$1"
if [[ -z "$device" ]]; then
  devices="$("${ZIRCON_TOOLS_DIR}/netls" | awk '/device /{print $2}')"
  if [[ -z "${devices}" ]]; then
    echo 2>&1 "No devices discovered, please supply a device name"
    exit 1
  fi
  if [[ "$(echo "$devices" | wc -l)" -ge 2 ]]; then
    echo 2>&1 "Multiple devices found, please pick one from the list:"
    device=$(select_device "$devices")
  else
    device="${devices}"
  fi
fi

if [[ ! -d "${FUCHSIA_BUILD_DIR}" ]]; then
  echo 2>&1 "Build directory ${FUCHSIA_BUILD_DIR} does not exist, run \"fx set\" first."
  exit 1
fi

echo "New default device: ${device}"
echo "$device" > "${FUCHSIA_BUILD_DIR}.device"