#!/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.

### start the update server and attach to a running fuchsia device
## usage: fx serve-updates [-v] [-l host[:port]]
##   -l host:port for "pm serve" to listen on
##   -v verbose (do not suppress `pm serve` output)

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

function usage {
  fx-command-help serve-updates
}

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

port="8083"
serve_flags=()
verbose=false
very_verbose=false
while (($#)); do
  case "$1" in
    -l)
      shift
      port="${1##*:}"
      serve_flags+=(-l "$1")
      ;;
    -v|--verbose)
      if $verbose; then
        very_verbose=true
      else
        verbose=true
      fi
      ;;
    -vv)
      verbose=true
      very_verbose=true
      ;;
    *)
      echo "Unrecognized option: $1"
      usage
      exit 1
      ;;
  esac
  shift
done

if [[ "${verbose}" != true ]]; then
  serve_flags+=("-q")
fi

pm_srv_pid=
cleanup() {
  if [[ -n "${pm_srv_pid}" ]]; then
    if kill -0 "${pm_srv_pid}" 2> /dev/null; then
      kill -TERM "${pm_srv_pid}" 2> /dev/null
      wait "${pm_srv_pid}" 2> /dev/null
    fi
  fi
}
trap cleanup EXIT

log() {
  # This format matches bootserver so that `fx serve` ui is easier to read.
  echo "$(date '+%Y-%m-%d %H:%M:%S') [serve-updates] $@"
}

log_verbose() {
  if [[ "$very_verbose" == true ]]; then
    log "$@"
  fi
}

if [[ -z "${pm_srv_pid}" ]]; then
  # The use of host_x64/ is deliberate over tools/.
  "${FUCHSIA_BUILD_DIR}/host_x64/pm" serve -repo "${FUCHSIA_BUILD_DIR}/amber-files" "${serve_flags[@]}" &
  pm_srv_pid=$!
fi

# Allow a little slack for pm serve to startup, that way the first kill -0 will catch a dead server
sleep 0.1
if ! kill -0 "${pm_srv_pid}" 2> /dev/null; then
  log "Server died, exiting"
  wait
  exit $?
fi

log "Discovery..."

# State is used to prevent too much output
state="discover"
while true; do
  if ! kill -0 "${pm_srv_pid}" 2> /dev/null; then
    log "Server died, exiting"
    pm_srv_pid=
    exit 1
  fi
  
  fx-command-run shell -o ConnectionAttempts=1 -o ConnectTimeout=1 echo >/dev/null 2>&1
  ping_result=$?

  if [[ "$state" == "discover" && "$ping_result" == 0 ]]; then
    log "Device up"
    state="config"
  fi

  if [[ "$state" == "config" ]]; then
    log "Registering devhost as update source"
    if fx-command-run add-update-source --port "${port}"; then
      log "Ready to push packages!"
      state="ready"
    else
      log "Device lost while configuring update source"
      state="discover"
    fi
  fi

  if [[ "$state" == "ready" ]]; then
    if [[ "$ping_result" != 0 ]]; then
      log "Device lost"
      state="discover"
    else
      sleep 1
    fi
  fi
done

# See EXIT trap above for cleanup that occurs