#!/bin/bash
#
# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
#
# Script that turns on useful logging for modem managers.


MM_LEVEL_LIST="err warn info debug"

usage() {
  echo "
Usage: mm_debug <level>|--reset|--help|--list_valid_levels

  mm_debug sets the log level of all running modem managers.

  <level> : The log level of modem managers to set to. Valid log levels
            can be viewed by using the --list_valid_levels option.

            e.g. mm_debug err
              Sets the log level of all running modem managers to 'err'.

  --reset : Resets the log level of all running modem managers to 'info'.

  --help : Displays this output.

  --list_valid_levels: Displays all valid log levels.
"
}

dbus_call() {
  local dest=$1
  local object_path=$2
  local method=$3
  shift 3
  dbus-send --print-reply --fixed --system --dest=$dest \
      "$object_path" "$method" "$@"
}

# Lists all valid log levels.
list_valid_levels() {
  echo "Valid levels are: ${MM_LEVEL_LIST// /, }"
}

# Returns whether or not $2 exists in $1 where $1 is a space-separated
# list of log levels.
is_valid_level() {
  expr match " $1 " ".* $2 .*"> /dev/null
}

# Returns all modem managers that are currently running.
get_all_modem_managers() {
  dbus_call org.freedesktop.DBus /org/freedesktop/DBus \
      org.freedesktop.DBus.ListNames | awk '/ModemManager/ { print $2 }'
}

# Sets the log level of the specified modem manager.
set_modem_manager_logging() {
  local manager=$1
  local level=$2
  local object_path=
  local method=

  case "$manager" in
    org.chromium.ModemManager)
      object_path=/org/chromium/ModemManager
      method=org.freedesktop.ModemManager.SetLogging
      if [[ "$level" == "err" ]]; then
        level=error
      fi
      ;;
    org.freedesktop.ModemManager)
      object_path=/org/freedesktop/ModemManager
      method=org.freedesktop.ModemManager.SetLogging
      ;;
    org.freedesktop.ModemManager1)
      object_path=/org/freedesktop/ModemManager1
      method=org.freedesktop.ModemManager1.SetLogging
      ;;
    *)
      return 1
      ;;
  esac

  dbus_call "$manager" "$object_path" "$method" "string:$level"
}

# Sets the log level of all modem managers that are currently running.
set_all_modem_managers_logging() {
  local level=$1

  if ! is_valid_level "$MM_LEVEL_LIST" "$level"; then
    echo "ERROR: '$level' is not a valid level."
    list_valid_levels
    return 1
  fi

  for manager in $(get_all_modem_managers); do
    set_modem_manager_logging "$manager" "$level"
  done
}


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

case "$1" in
  --reset)
    set_all_modem_managers_logging "info"
    ;;
  --list_valid_levels)
    list_valid_levels
    ;;
  --help|--*)
    usage
    ;;
  *)
    set_all_modem_managers_logging "$1"
    ;;
esac