# pylint: disable-msg=C0111

# 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.

__author__ = 'cmasone@chromium.org (Chris Masone)'

import common
import ConfigParser
import datetime
import logging
import os
import shutil

from autotest_lib.frontend.afe import models
from autotest_lib.client.common_lib import error
from autotest_lib.client.common_lib import global_config
from autotest_lib.client.common_lib import priorities
from autotest_lib.client.common_lib import time_utils
from autotest_lib.client.common_lib.cros import dev_server
from autotest_lib.client.common_lib.cros.graphite import autotest_stats
from autotest_lib.frontend.afe import rpc_utils
from autotest_lib.server import utils
from autotest_lib.server.cros.dynamic_suite import constants
from autotest_lib.server.cros.dynamic_suite import control_file_getter
from autotest_lib.server.cros.dynamic_suite import tools
from autotest_lib.server.hosts import moblab_host
from autotest_lib.site_utils import host_history
from autotest_lib.site_utils import job_history
from autotest_lib.site_utils import server_manager_utils
from autotest_lib.site_utils import stable_version_utils


_CONFIG = global_config.global_config
MOBLAB_BOTO_LOCATION = '/home/moblab/.boto'

# Relevant CrosDynamicSuiteExceptions are defined in client/common_lib/error.py.


def canonicalize_suite_name(suite_name):
    return 'test_suites/control.%s' % suite_name


def formatted_now():
    return datetime.datetime.now().strftime(time_utils.TIME_FMT)


def _get_control_file_contents_by_name(build, ds, suite_name):
    """Return control file contents for |suite_name|.

    Query the dev server at |ds| for the control file |suite_name|, included
    in |build| for |board|.

    @param build: unique name by which to refer to the image from now on.
    @param ds: a dev_server.DevServer instance to fetch control file with.
    @param suite_name: canonicalized suite name, e.g. test_suites/control.bvt.
    @raises ControlFileNotFound if a unique suite control file doesn't exist.
    @raises NoControlFileList if we can't list the control files at all.
    @raises ControlFileEmpty if the control file exists on the server, but
                             can't be read.

    @return the contents of the desired control file.
    """
    getter = control_file_getter.DevServerGetter.create(build, ds)
    timer = autotest_stats.Timer('control_files.parse.%s.%s' %
                                 (ds.get_server_name(ds.url()
                                                     ).replace('.', '_'),
                                  suite_name.rsplit('.')[-1]))
    # Get the control file for the suite.
    try:
        with timer:
            control_file_in = getter.get_control_file_contents_by_name(
                    suite_name)
    except error.CrosDynamicSuiteException as e:
        raise type(e)("%s while testing %s." % (e, build))
    if not control_file_in:
        raise error.ControlFileEmpty(
                "Fetching %s returned no data." % suite_name)
    # Force control files to only contain ascii characters.
    try:
        control_file_in.encode('ascii')
    except UnicodeDecodeError as e:
        raise error.ControlFileMalformed(str(e))

    return control_file_in


def _stage_build_artifacts(build):
    """
    Ensure components of |build| necessary for installing images are staged.

    @param build image we want to stage.

    @raises StageControlFileFailure: if the dev server throws 500 while staging
        suite control files.

    @return: dev_server.ImageServer instance to use with this build.
    @return: timings dictionary containing staging start/end times.
    """
    timings = {}
    # Ensure components of |build| necessary for installing images are staged
    # on the dev server. However set synchronous to False to allow other
    # components to be downloaded in the background.
    ds = dev_server.ImageServer.resolve(build)
    timings[constants.DOWNLOAD_STARTED_TIME] = formatted_now()
    timer = autotest_stats.Timer('control_files.stage.%s' % (
            ds.get_server_name(ds.url()).replace('.', '_')))
    try:
        with timer:
            ds.stage_artifacts(build, ['test_suites'])
    except dev_server.DevServerException as e:
        raise error.StageControlFileFailure(
                "Failed to stage %s: %s" % (build, e))
    timings[constants.PAYLOAD_FINISHED_TIME] = formatted_now()
    return (ds, timings)


def create_suite_job(name='', board='', build='', pool='', control_file='',
                     check_hosts=True, num=None, file_bugs=False, timeout=24,
                     timeout_mins=None, priority=priorities.Priority.DEFAULT,
                     suite_args=None, wait_for_results=True, job_retry=False,
                     max_retries=None, max_runtime_mins=None, suite_min_duts=0,
                     offload_failures_only=False, **kwargs):
    """
    Create a job to run a test suite on the given device with the given image.

    When the timeout specified in the control file is reached, the
    job is guaranteed to have completed and results will be available.

    @param name: The test name if control_file is supplied, otherwise the name
                 of the test suite to run, e.g. 'bvt'.
    @param board: the kind of device to run the tests on.
    @param build: unique name by which to refer to the image from now on.
    @param pool: Specify the pool of machines to use for scheduling
            purposes.
    @param check_hosts: require appropriate live hosts to exist in the lab.
    @param num: Specify the number of machines to schedule across (integer).
                Leave unspecified or use None to use default sharding factor.
    @param file_bugs: File a bug on each test failure in this suite.
    @param timeout: The max lifetime of this suite, in hours.
    @param timeout_mins: The max lifetime of this suite, in minutes. Takes
                         priority over timeout.
    @param priority: Integer denoting priority. Higher is more important.
    @param suite_args: Optional arguments which will be parsed by the suite
                       control file. Used by control.test_that_wrapper to
                       determine which tests to run.
    @param wait_for_results: Set to False to run the suite job without waiting
                             for test jobs to finish. Default is True.
    @param job_retry: Set to True to enable job-level retry. Default is False.
    @param max_retries: Integer, maximum job retries allowed at suite level.
                        None for no max.
    @param max_runtime_mins: Maximum amount of time a job can be running in
                             minutes.
    @param suite_min_duts: Integer. Scheduler will prioritize getting the
                           minimum number of machines for the suite when it is
                           competing with another suite that has a higher
                           priority but already got minimum machines it needs.
    @param offload_failures_only: Only enable gs_offloading for failed jobs.
    @param kwargs: extra keyword args. NOT USED.

    @raises ControlFileNotFound: if a unique suite control file doesn't exist.
    @raises NoControlFileList: if we can't list the control files at all.
    @raises StageControlFileFailure: If the dev server throws 500 while
                                     staging test_suites.
    @raises ControlFileEmpty: if the control file exists on the server, but
                              can't be read.

    @return: the job ID of the suite; -1 on error.
    """
    if type(num) is not int and num is not None:
        raise error.SuiteArgumentException('Ill specified num argument %r. '
                                           'Must be an integer or None.' % num)
    if num == 0:
        logging.warning("Can't run on 0 hosts; using default.")
        num = None
    (ds, keyvals) = _stage_build_artifacts(build)
    keyvals[constants.SUITE_MIN_DUTS_KEY] = suite_min_duts

    if not control_file:
      # No control file was supplied so look it up from the build artifacts.
      suite_name = canonicalize_suite_name(name)
      control_file = _get_control_file_contents_by_name(build, ds, suite_name)
      name = '%s-%s' % (build, suite_name)

    timeout_mins = timeout_mins or timeout * 60
    max_runtime_mins = max_runtime_mins or timeout * 60

    if not board:
        board = utils.ParseBuildName(build)[0]

    # Prepend build and board to the control file.
    inject_dict = {'board': board,
                   'build': build,
                   'check_hosts': check_hosts,
                   'pool': pool,
                   'num': num,
                   'file_bugs': file_bugs,
                   'timeout': timeout,
                   'timeout_mins': timeout_mins,
                   'devserver_url': ds.url(),
                   'priority': priority,
                   'suite_args' : suite_args,
                   'wait_for_results': wait_for_results,
                   'job_retry': job_retry,
                   'max_retries': max_retries,
                   'max_runtime_mins': max_runtime_mins,
                   'offload_failures_only': offload_failures_only
                   }

    control_file = tools.inject_vars(inject_dict, control_file)

    return rpc_utils.create_job_common(name,
                                       priority=priority,
                                       timeout_mins=timeout_mins,
                                       max_runtime_mins=max_runtime_mins,
                                       control_type='Server',
                                       control_file=control_file,
                                       hostless=True,
                                       keyvals=keyvals)


# TODO: hide the following rpcs under is_moblab
def moblab_only(func):
    """Ensure moblab specific functions only run on Moblab devices."""
    def verify(*args, **kwargs):
        if not utils.is_moblab():
            raise error.RPCException('RPC: %s can only run on Moblab Systems!',
                                     func.__name__)
        return func(*args, **kwargs)
    return verify


@moblab_only
def get_config_values():
    """Returns all config values parsed from global and shadow configs.

    Config values are grouped by sections, and each section is composed of
    a list of name value pairs.
    """
    sections =_CONFIG.get_sections()
    config_values = {}
    for section in sections:
        config_values[section] = _CONFIG.config.items(section)
    return rpc_utils.prepare_for_serialization(config_values)


@moblab_only
def update_config_handler(config_values):
    """
    Update config values and override shadow config.

    @param config_values: See get_moblab_settings().
    """
    original_config = global_config.global_config_class()
    original_config.set_config_files(shadow_file='')
    new_shadow = ConfigParser.RawConfigParser()
    for section, config_value_list in config_values.iteritems():
        for key, value in config_value_list:
            if original_config.get_config_value(section, key,
                                                default='',
                                                allow_blank=True) != value:
                if not new_shadow.has_section(section):
                    new_shadow.add_section(section)
                new_shadow.set(section, key, value)
    if not _CONFIG.shadow_file or not os.path.exists(_CONFIG.shadow_file):
        raise error.RPCException('Shadow config file does not exist.')

    with open(_CONFIG.shadow_file, 'w') as config_file:
        new_shadow.write(config_file)
    # TODO (sbasi) crbug.com/403916 - Remove the reboot command and
    # instead restart the services that rely on the config values.
    os.system('sudo reboot')


@moblab_only
def reset_config_settings():
    with open(_CONFIG.shadow_file, 'w') as config_file:
      pass
    os.system('sudo reboot')


@moblab_only
def set_boto_key(boto_key):
    """Update the boto_key file.

    @param boto_key: File name of boto_key uploaded through handle_file_upload.
    """
    if not os.path.exists(boto_key):
        raise error.RPCException('Boto key: %s does not exist!' % boto_key)
    shutil.copyfile(boto_key, moblab_host.MOBLAB_BOTO_LOCATION)


def get_job_history(**filter_data):
    """Get history of the job, including the special tasks executed for the job

    @param filter_data: filter for the call, should at least include
                        {'job_id': [job id]}
    @returns: JSON string of the job's history, including the information such
              as the hosts run the job and the special tasks executed before
              and after the job.
    """
    job_id = filter_data['job_id']
    job_info = job_history.get_job_info(job_id)
    return rpc_utils.prepare_for_serialization(job_info.get_history())


def get_host_history(start_time, end_time, hosts=None, board=None, pool=None):
    """Get history of a list of host.

    The return is a JSON string of host history for each host, for example,
    {'172.22.33.51': [{'status': 'Resetting'
                       'start_time': '2014-08-07 10:02:16',
                       'end_time': '2014-08-07 10:03:16',
                       'log_url': 'http://autotest/reset-546546/debug',
                       'dbg_str': 'Task: Special Task 19441991 (host ...)'},
                       {'status': 'Running'
                       'start_time': '2014-08-07 10:03:18',
                       'end_time': '2014-08-07 10:13:00',
                       'log_url': 'http://autotest/reset-546546/debug',
                       'dbg_str': 'HQE: 15305005, for job: 14995562'}
                     ]
    }
    @param start_time: start time to search for history, can be string value or
                       epoch time.
    @param end_time: end time to search for history, can be string value or
                     epoch time.
    @param hosts: A list of hosts to search for history. Default is None.
    @param board: board type of hosts. Default is None.
    @param pool: pool type of hosts. Default is None.
    @returns: JSON string of the host history.
    """
    return rpc_utils.prepare_for_serialization(
            host_history.get_history_details(
                    start_time=start_time, end_time=end_time,
                    hosts=hosts, board=board, pool=pool,
                    process_pool_size=4))


def shard_heartbeat(shard_hostname, jobs=(), hqes=(),
                    known_job_ids=(), known_host_ids=()):
    """Receive updates for job statuses from shards and assign hosts and jobs.

    @param shard_hostname: Hostname of the calling shard
    @param jobs: Jobs in serialized form that should be updated with newer
                 status from a shard.
    @param hqes: Hostqueueentries in serialized form that should be updated with
                 newer status from a shard. Note that for every hostqueueentry
                 the corresponding job must be in jobs.
    @param known_job_ids: List of ids of jobs the shard already has.
    @param known_host_ids: List of ids of hosts the shard already has.

    @returns: Serialized representations of hosts, jobs, suite job keyvals
              and their dependencies to be inserted into a shard's database.
    """
    # The following alternatives to sending host and job ids in every heartbeat
    # have been considered:
    # 1. Sending the highest known job and host ids. This would work for jobs:
    #    Newer jobs always have larger ids. Also, if a job is not assigned to a
    #    particular shard during a heartbeat, it never will be assigned to this
    #    shard later.
    #    This is not true for hosts though: A host that is leased won't be sent
    #    to the shard now, but might be sent in a future heartbeat. This means
    #    sometimes hosts should be transfered that have a lower id than the
    #    maximum host id the shard knows.
    # 2. Send the number of jobs/hosts the shard knows to the master in each
    #    heartbeat. Compare these to the number of records that already have
    #    the shard_id set to this shard. In the normal case, they should match.
    #    In case they don't, resend all entities of that type.
    #    This would work well for hosts, because there aren't that many.
    #    Resending all jobs is quite a big overhead though.
    #    Also, this approach might run into edge cases when entities are
    #    ever deleted.
    # 3. Mixtures of the above: Use 1 for jobs and 2 for hosts.
    #    Using two different approaches isn't consistent and might cause
    #    confusion. Also the issues with the case of deletions might still
    #    occur.
    #
    # The overhead of sending all job and host ids in every heartbeat is low:
    # At peaks one board has about 1200 created but unfinished jobs.
    # See the numbers here: http://goo.gl/gQCGWH
    # Assuming that job id's have 6 digits and that json serialization takes a
    # comma and a space as overhead, the traffic per id sent is about 8 bytes.
    # If 5000 ids need to be sent, this means 40 kilobytes of traffic.
    # A NOT IN query with 5000 ids took about 30ms in tests made.
    # These numbers seem low enough to outweigh the disadvantages of the
    # solutions described above.
    timer = autotest_stats.Timer('shard_heartbeat')
    with timer:
        shard_obj = rpc_utils.retrieve_shard(shard_hostname=shard_hostname)
        rpc_utils.persist_records_sent_from_shard(shard_obj, jobs, hqes)
        hosts, jobs, suite_keyvals = rpc_utils.find_records_for_shard(
            shard_obj,
            known_job_ids=known_job_ids, known_host_ids=known_host_ids)
        return {
            'hosts': [host.serialize() for host in hosts],
            'jobs': [job.serialize() for job in jobs],
            'suite_keyvals': [kv.serialize() for kv in suite_keyvals],
        }


def get_shards(**filter_data):
    """Return a list of all shards.

    @returns A sequence of nested dictionaries of shard information.
    """
    shards = models.Shard.query_objects(filter_data)
    serialized_shards = rpc_utils.prepare_rows_as_nested_dicts(shards, ())
    for serialized, shard in zip(serialized_shards, shards):
        serialized['labels'] = [label.name for label in shard.labels.all()]

    return serialized_shards


def add_shard(hostname, label):
    """Add a shard and start running jobs on it.

    @param hostname: The hostname of the shard to be added; needs to be unique.
    @param label: A platform label. Jobs of this label will be assigned to the
                  shard.

    @raises error.RPCException: If label provided doesn't start with `board:`
    @raises model_logic.ValidationError: If a shard with the given hostname
            already exists.
    @raises models.Label.DoesNotExist: If the label specified doesn't exist.
    """
    if not label.startswith('board:'):
        raise error.RPCException('Sharding only supported for `board:.*` '
                                 'labels.')

    # Fetch label first, so shard isn't created when label doesn't exist.
    label = models.Label.smart_get(label)
    shard = models.Shard.add_object(hostname=hostname)
    shard.labels.add(label)
    return shard.id


def delete_shard(hostname):
    """Delete a shard and reclaim all resources from it.

    This claims back all assigned hosts from the shard. To ensure all DUTs are
    in a sane state, a Repair task is scheduled for them. This reboots the DUTs
    and therefore clears all running processes that might be left.

    The shard_id of jobs of that shard will be set to None.

    The status of jobs that haven't been reported to be finished yet, will be
    lost. The master scheduler will pick up the jobs and execute them.

    @param hostname: Hostname of the shard to delete.
    """
    shard = rpc_utils.retrieve_shard(shard_hostname=hostname)

    # TODO(beeps): Power off shard

    # For ChromeOS hosts, repair reboots the DUT.
    # Repair will excalate through multiple repair steps and will verify the
    # success after each of them. Anyway, it will always run at least the first
    # one, which includes a reboot.
    # After a reboot we can be sure no processes from prior tests that were run
    # by a shard are still running on the DUT.
    # Important: Don't just set the status to Repair Failed, as that would run
    # Verify first, before doing any repair measures. Verify would probably
    # succeed, so this wouldn't change anything on the DUT.
    for host in models.Host.objects.filter(shard=shard):
            models.SpecialTask.objects.create(
                    task=models.SpecialTask.Task.REPAIR,
                    host=host,
                    requested_by=models.User.current_user())
    models.Host.objects.filter(shard=shard).update(shard=None)

    models.Job.objects.filter(shard=shard).update(shard=None)

    shard.labels.clear()

    shard.delete()


def get_servers(role=None, status=None):
    """Get a list of servers with matching role and status.

    @param role: Name of the server role, e.g., drone, scheduler. Default to
                 None to match any role.
    @param status: Status of the server, e.g., primary, backup, repair_required.
                   Default to None to match any server status.

    @raises error.RPCException: If server database is not used.
    @return: A list of server names for servers with matching role and status.
    """
    if not server_manager_utils.use_server_db():
        raise error.RPCException('Server database is not enabled. Please try '
                                 'retrieve servers from global config.')
    servers = server_manager_utils.get_servers(hostname=None, role=role,
                                               status=status)
    return [s.get_details() for s in servers]


def get_stable_version(board=stable_version_utils.DEFAULT):
    """Get stable version for the given board.

    @param board: Name of the board.
    @return: Stable version of the given board. Return global configure value
             of CROS.stable_cros_version if stable_versinos table does not have
             entry of board DEFAULT.
    """
    # This RPC call should be accepted only by master.
    if utils.is_shard():
        return rpc_utils.route_rpc_to_master('get_stable_version', board=board)
    return stable_version_utils.get(board)


def get_all_stable_versions():
    """Get stable versions for all boards.

    @return: A dictionary of board:version.
    """
    # This RPC call should be accepted only by master.
    if utils.is_shard():
        return rpc_utils.route_rpc_to_master('get_all_stable_versions')
    return stable_version_utils.get_all()


def set_stable_version(version, board=stable_version_utils.DEFAULT):
    """Modify stable version for the given board.

    @param version: The new value of stable version for given board.
    @param board: Name of the board, default to value `DEFAULT`.
    """
    # This RPC call should be accepted only by master.
    if utils.is_shard():
        return rpc_utils.route_rpc_to_master('set_stable_version',
                                             version=version, board=board)
    stable_version_utils.set(version=version, board=board)


def delete_stable_version(board):
    """Modify stable version for the given board.

    Delete a stable version entry in afe_stable_versions table for a given
    board, so default stable version will be used.

    @param board: Name of the board.
    """
    # This RPC call should be accepted only by master.
    if utils.is_shard():
        return rpc_utils.route_rpc_to_master('delete_stable_version',
                                             board=board)
    stable_version_utils.delete(board=board)