# Copyright 2015 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.

"""An adapter to remotely access the system facade on DUT."""


class SystemFacadeRemoteAdapter(object):
    """SystemFacadeRemoteAdapter is an adapter to remotely control DUT system.

    The Autotest host object representing the remote DUT, passed to this
    class on initialization, can be accessed from its _client property.

    """
    def __init__(self, host, remote_facade_proxy):
        """Construct an SystemFacadeRemoteAdapter.

        @param host: Host object representing a remote host.
        @param remote_facade_proxy: RemoteFacadeProxy object.

        """
        self._client = host
        self._proxy = remote_facade_proxy


    @property
    def _system_proxy(self):
        """Gets the proxy to DUT system facade.

        @return XML RPC proxy to DUT system facade.

        """
        return self._proxy.system


    def set_scaling_governor_mode(self, index, mode):
        """Set mode of CPU scaling governor on one CPU of DUT.

        @param index: CPU index starting from 0.

        @param mode: Mode of scaling governor, accept 'interactive' or
                     'performance'.

        @returns: The original mode.

        """
        return self._system_proxy.set_scaling_governor_mode(index, mode)


    def get_cpu_usage(self):
        """Returns machine's CPU usage.

        Returns:
            A dictionary with 'user', 'nice', 'system' and 'idle' values.
            Sample dictionary:
            {
                'user': 254544,
                'nice': 9,
                'system': 254768,
                'idle': 2859878,
            }
        """
        return self._system_proxy.get_cpu_usage()


    def compute_active_cpu_time(self, cpu_usage_start, cpu_usage_end):
        """Computes the fraction of CPU time spent non-idling.

        This function should be invoked using before/after values from calls to
        get_cpu_usage().
        """
        return self._system_proxy.compute_active_cpu_time(cpu_usage_start,
                                                          cpu_usage_end)


    def get_mem_total(self):
        """Returns the total memory available in the system in MBytes."""
        return self._system_proxy.get_mem_total()


    def get_mem_free(self):
        """Returns the currently free memory in the system in MBytes."""
        return self._system_proxy.get_mem_free()


    def get_ec_temperatures(self):
        """Uses ectool to return a list of all sensor temperatures in Celsius.
        """
        return self._system_proxy.get_ec_temperatures()


    def get_current_board(self):
        """Returns the current device board name."""
        return self._system_proxy.get_current_board()


    def get_chromeos_release_version(self):
        """Returns chromeos version in device under test as string. None on
        fail.
        """
        return self._system_proxy.get_chromeos_release_version()