# Copyright (c) 2013 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.
import logging
import re
import os
import StringIO

import common
from autotest_lib.client.common_lib import error
from autotest_lib.server import test
from autotest_lib.server import utils
from autotest_lib.site_utils import test_runner_utils
from autotest_lib.server.cros import telemetry_runner


TELEMETRY_TIMEOUT_MINS = 60
CHROME_SRC_ROOT = '/var/cache/chromeos-cache/distfiles/target/'
CLIENT_CHROME_ROOT = '/usr/local/telemetry/src'
RUN_BENCHMARK  = 'tools/perf/run_benchmark'

RSA_KEY = '-i %s' % test_runner_utils.TEST_KEY_PATH
DUT_CHROME_RESULTS_DIR = '/usr/local/telemetry/src/tools/perf'

# Result Statuses
SUCCESS_STATUS = 'SUCCESS'
WARNING_STATUS = 'WARNING'
FAILED_STATUS = 'FAILED'

# Regex for the RESULT output lines understood by chrome buildbot.
# Keep in sync with
# chromium/tools/build/scripts/slave/performance_log_processor.py.
RESULTS_REGEX = re.compile(r'(?P<IMPORTANT>\*)?RESULT '
                           r'(?P<GRAPH>[^:]*): (?P<TRACE>[^=]*)= '
                           r'(?P<VALUE>[\{\[]?[-\d\., ]+[\}\]]?)('
                           r' ?(?P<UNITS>.+))?')
HISTOGRAM_REGEX = re.compile(r'(?P<IMPORTANT>\*)?HISTOGRAM '
                             r'(?P<GRAPH>[^:]*): (?P<TRACE>[^=]*)= '
                             r'(?P<VALUE_JSON>{.*})(?P<UNITS>.+)?')


def _find_chrome_root_dir():
    # Look for chrome source root, either externally mounted, or inside
    # the chroot.  Prefer chrome-src-internal source tree to chrome-src.
    sources_list = ('chrome-src-internal', 'chrome-src')

    dir_list = [os.path.join(CHROME_SRC_ROOT, x) for x in sources_list]
    if 'CHROME_ROOT' in os.environ:
        dir_list.insert(0, os.environ['CHROME_ROOT'])

    for dir in dir_list:
        if os.path.exists(dir):
            chrome_root_dir = dir
            break
    else:
        raise error.TestError('Chrome source directory not found.')

    logging.info('Using Chrome source tree at %s', chrome_root_dir)
    return os.path.join(chrome_root_dir, 'src')


def _ensure_deps(dut, test_name):
    """
    Ensure the dependencies are locally available on DUT.

    @param dut: The autotest host object representing DUT.
    @param test_name: Name of the telemetry test.
    """
    # Get DEPs using host's telemetry.
    chrome_root_dir = _find_chrome_root_dir()
    format_string = ('python %s/tools/perf/fetch_benchmark_deps.py %s')
    command = format_string % (chrome_root_dir, test_name)
    logging.info('Getting DEPs: %s', command)
    stdout = StringIO.StringIO()
    stderr = StringIO.StringIO()
    try:
        result = utils.run(command, stdout_tee=stdout,
                           stderr_tee=stderr)
    except error.CmdError as e:
        logging.debug('Error occurred getting DEPs: %s\n %s\n',
                      stdout.getvalue(), stderr.getvalue())
        raise error.TestFail('Error occurred while getting DEPs.')

    # Download DEPs to DUT.
    # send_file() relies on rsync over ssh. Couldn't be better.
    stdout_str = stdout.getvalue()
    stdout.close()
    stderr.close()
    for dep in stdout_str.split():
        src = os.path.join(chrome_root_dir, dep)
        dst = os.path.join(CLIENT_CHROME_ROOT, dep)
        if not os.path.isfile(src):
            raise error.TestFail('Error occurred while saving DEPs.')
        logging.info('Copying: %s -> %s', src, dst)
        try:
            dut.send_file(src, dst)
        except:
            raise error.TestFail('Error occurred while sending DEPs to dut.\n')


class telemetry_Crosperf(test.test):
    """Run one or more telemetry benchmarks under the crosperf script."""
    version = 1

    def scp_telemetry_results(self, client_ip, dut):
        """Copy telemetry results from dut.

        @param client_ip: The ip address of the DUT
        @param dut: The autotest host object representing DUT.

        @returns status code for scp command.
        """
        cmd=[]
        src = ('root@%s:%s/results-chart.json' %
               (dut.hostname if dut else client_ip, DUT_CHROME_RESULTS_DIR))
        cmd.extend(['scp', telemetry_runner.DUT_SCP_OPTIONS, RSA_KEY, '-v',
                    src, self.resultsdir])
        command = ' '.join(cmd)

        logging.debug('Retrieving Results: %s', command)
        try:
            result = utils.run(command,
                               timeout=TELEMETRY_TIMEOUT_MINS * 60)
            exit_code = result.exit_status
        except Exception as e:
            logging.error('Failed to retrieve results: %s', e)
            raise

        logging.debug('command return value: %d', exit_code)
        return exit_code

    def run_once(self, args, client_ip='', dut=None):
        """
        Run a single telemetry test.

        @param args: A dictionary of the arguments that were passed
                to this test.
        @param client_ip: The ip address of the DUT
        @param dut: The autotest host object representing DUT.

        @returns A TelemetryResult instance with the results of this execution.
        """
        test_name = args['test']
        test_args = ''
        if 'test_args' in args:
            test_args = args['test_args']

        # Decide whether the test will run locally or by a remote server.
        if args.get('run_local', 'false').lower() == 'true':
            # The telemetry scripts will run on DUT.
            _ensure_deps(dut, test_name)
            format_string = ('python %s --browser=system '
                             '--output-format=chartjson %s %s')
            command = format_string % (os.path.join(CLIENT_CHROME_ROOT,
                                                    RUN_BENCHMARK),
                                       test_args, test_name)
            runner = dut
        else:
            # The telemetry scripts will run on server.
            format_string = ('python %s --browser=cros-chrome --remote=%s '
                             '--output-format=chartjson %s %s')
            command = format_string % (os.path.join(_find_chrome_root_dir(),
                                                    RUN_BENCHMARK),
                                       client_ip, test_args, test_name)
            runner = utils

        # Run the test.
        stdout = StringIO.StringIO()
        stderr = StringIO.StringIO()
        try:
            logging.info('CMD: %s', command)
            result = runner.run(command, stdout_tee=stdout, stderr_tee=stderr,
                                timeout=TELEMETRY_TIMEOUT_MINS*60)
            exit_code = result.exit_status
        except error.CmdError as e:
            logging.debug('Error occurred executing telemetry.')
            exit_code = e.result_obj.exit_status
            raise error.TestFail('An error occurred while executing '
                                 'telemetry test.')
        finally:
            stdout_str = stdout.getvalue()
            stderr_str = stderr.getvalue()
            stdout.close()
            stderr.close()

        logging.info('Telemetry completed with exit code: %d.'
                     '\nstdout:%s\nstderr:%s', exit_code,
                     stdout_str, stderr_str)

        # Copy the results-chart.json file into the test_that results
        # directory.
        if args.get('run_local', 'false').lower() == 'true':
            result = self.scp_telemetry_results(client_ip, dut)
        else:
            src_dir = os.path.dirname(os.path.join(_find_chrome_root_dir(),
                                                   RUN_BENCHMARK))

            filepath = os.path.join(src_dir, 'results-chart.json')
            if os.path.exists(filepath):
                command = 'cp %s %s' % (filepath, self.resultsdir)
                result = utils.run(command)
            else:
                raise IOError('Missing results file: %s' % filepath)


        return result