#!/usr/bin/env python
# Copyright (C) 2012 Google Inc. All rights reserved.
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import errno
import logging
import math
import re
import os
import signal
import socket
import subprocess
import sys
import time

# Import for auto-install
if sys.platform not in ('cygwin', 'win32'):
    # FIXME: webpagereplay doesn't work on win32. See https://bugs.webkit.org/show_bug.cgi?id=88279.
    import webkitpy.thirdparty.autoinstalled.webpagereplay.replay

from webkitpy.layout_tests.controllers.test_result_writer import TestResultWriter
from webkitpy.layout_tests.port.driver import DriverInput
from webkitpy.layout_tests.port.driver import DriverOutput


_log = logging.getLogger(__name__)


class PerfTest(object):
    def __init__(self, port, test_name, path_or_url):
        self._port = port
        self._test_name = test_name
        self._path_or_url = path_or_url

    def test_name(self):
        return self._test_name

    def path_or_url(self):
        return self._path_or_url

    def prepare(self, time_out_ms):
        return True

    def run(self, driver, time_out_ms):
        output = self.run_single(driver, self.path_or_url(), time_out_ms)
        if self.run_failed(output):
            return None
        return self.parse_output(output)

    def run_single(self, driver, path_or_url, time_out_ms, should_run_pixel_test=False):
        return driver.run_test(DriverInput(path_or_url, time_out_ms, image_hash=None, should_run_pixel_test=should_run_pixel_test), stop_when_done=False)

    def run_failed(self, output):
        if output.text == None or output.error:
            pass
        elif output.timeout:
            _log.error('timeout: %s' % self.test_name())
        elif output.crash:
            _log.error('crash: %s' % self.test_name())
        else:
            return False

        if output.error:
            _log.error('error: %s\n%s' % (self.test_name(), output.error))

        return True

    _lines_to_ignore_in_parser_result = [
        re.compile(r'^Running \d+ times$'),
        re.compile(r'^Ignoring warm-up '),
        re.compile(r'^Info:'),
        re.compile(r'^\d+(.\d+)?(\s*(runs\/s|ms|fps))?$'),
        # Following are for handle existing test like Dromaeo
        re.compile(re.escape("""main frame - has 1 onunload handler(s)""")),
        re.compile(re.escape("""frame "<!--framePath //<!--frame0-->-->" - has 1 onunload handler(s)""")),
        re.compile(re.escape("""frame "<!--framePath //<!--frame0-->/<!--frame0-->-->" - has 1 onunload handler(s)""")),
        # Following is for html5.html
        re.compile(re.escape("""Blocked access to external URL http://www.whatwg.org/specs/web-apps/current-work/"""))]

    def _should_ignore_line_in_parser_test_result(self, line):
        if not line:
            return True
        for regex in self._lines_to_ignore_in_parser_result:
            if regex.search(line):
                return True
        return False

    _description_regex = re.compile(r'^Description: (?P<description>.*)$', re.IGNORECASE)
    _result_classes = ['Time', 'JS Heap', 'Malloc']
    _result_class_regex = re.compile(r'^(?P<resultclass>' + r'|'.join(_result_classes) + '):')
    _statistics_keys = ['avg', 'median', 'stdev', 'min', 'max', 'unit', 'values']
    _score_regex = re.compile(r'^(?P<key>' + r'|'.join(_statistics_keys) + r')\s+(?P<value>([0-9\.]+(,\s+)?)+)\s*(?P<unit>.*)')

    def parse_output(self, output):
        test_failed = False
        results = {}
        ordered_results_keys = []
        test_name = re.sub(r'\.\w+$', '', self._test_name)
        description_string = ""
        result_class = ""
        for line in re.split('\n', output.text):
            description = self._description_regex.match(line)
            if description:
                description_string = description.group('description')
                continue

            result_class_match = self._result_class_regex.match(line)
            if result_class_match:
                result_class = result_class_match.group('resultclass')
                continue

            score = self._score_regex.match(line)
            if score:
                key = score.group('key')
                if key == 'values':
                    value = [float(number) for number in score.group('value').split(', ')]
                else:
                    value = float(score.group('value'))
                unit = score.group('unit')
                name = test_name
                if result_class != 'Time':
                    name += ':' + result_class.replace(' ', '')
                if name not in ordered_results_keys:
                    ordered_results_keys.append(name)
                results.setdefault(name, {})
                results[name]['unit'] = unit
                results[name][key] = value
                continue

            if not self._should_ignore_line_in_parser_test_result(line):
                test_failed = True
                _log.error(line)

        if test_failed:
            return None

        if set(self._statistics_keys) != set(results[test_name].keys() + ['values']):
            # values is not provided by Dromaeo tests.
            _log.error("The test didn't report all statistics.")
            return None

        for result_name in ordered_results_keys:
            if result_name == test_name:
                self.output_statistics(result_name, results[result_name], description_string)
            else:
                self.output_statistics(result_name, results[result_name])
        return results

    def output_statistics(self, test_name, results, description_string=None):
        unit = results['unit']
        if description_string:
            _log.info('DESCRIPTION: %s' % description_string)
        _log.info('RESULT %s= %s %s' % (test_name.replace(':', ': ').replace('/', ': '), results['avg'], unit))
        _log.info(', '.join(['%s= %s %s' % (key, results[key], unit) for key in self._statistics_keys[1:5]]))


class ChromiumStylePerfTest(PerfTest):
    _chromium_style_result_regex = re.compile(r'^RESULT\s+(?P<name>[^=]+)\s*=\s+(?P<value>\d+(\.\d+)?)\s*(?P<unit>\w+)$')

    def __init__(self, port, test_name, path_or_url):
        super(ChromiumStylePerfTest, self).__init__(port, test_name, path_or_url)

    def parse_output(self, output):
        test_failed = False
        results = {}
        for line in re.split('\n', output.text):
            resultLine = ChromiumStylePerfTest._chromium_style_result_regex.match(line)
            if resultLine:
                # FIXME: Store the unit
                results[self.test_name() + ':' + resultLine.group('name').replace(' ', '')] = float(resultLine.group('value'))
                _log.info(line)
            elif not len(line) == 0:
                test_failed = True
                _log.error(line)
        return results if results and not test_failed else None


class PageLoadingPerfTest(PerfTest):
    _FORCE_GC_FILE = 'resources/force-gc.html'

    def __init__(self, port, test_name, path_or_url):
        super(PageLoadingPerfTest, self).__init__(port, test_name, path_or_url)
        self.force_gc_test = self._port.host.filesystem.join(self._port.perf_tests_dir(), self._FORCE_GC_FILE)

    def run_single(self, driver, path_or_url, time_out_ms, should_run_pixel_test=False):
        # Force GC to prevent pageload noise. See https://bugs.webkit.org/show_bug.cgi?id=98203
        super(PageLoadingPerfTest, self).run_single(driver, self.force_gc_test, time_out_ms, False)
        return super(PageLoadingPerfTest, self).run_single(driver, path_or_url, time_out_ms, should_run_pixel_test)

    def run(self, driver, time_out_ms):
        test_times = []

        for i in range(0, 20):
            output = self.run_single(driver, self.path_or_url(), time_out_ms)
            if not output or self.run_failed(output):
                return None
            if i == 0:
                continue
            test_times.append(output.test_time * 1000)

        sorted_test_times = sorted(test_times)

        # Compute the mean and variance using Knuth's online algorithm (has good numerical stability).
        squareSum = 0
        mean = 0
        for i, time in enumerate(sorted_test_times):
            delta = time - mean
            sweep = i + 1.0
            mean += delta / sweep
            squareSum += delta * (time - mean)

        middle = int(len(test_times) / 2)
        results = {'values': test_times,
            'avg': mean,
            'min': sorted_test_times[0],
            'max': sorted_test_times[-1],
            'median': sorted_test_times[middle] if len(sorted_test_times) % 2 else (sorted_test_times[middle - 1] + sorted_test_times[middle]) / 2,
            'stdev': math.sqrt(squareSum / (len(sorted_test_times) - 1)),
            'unit': 'ms'}
        self.output_statistics(self.test_name(), results, '')
        return {self.test_name(): results}


class ReplayServer(object):
    def __init__(self, archive, record):
        self._process = None

        # FIXME: Should error if local proxy isn't set to forward requests to localhost:8080 and localhost:8443

        replay_path = webkitpy.thirdparty.autoinstalled.webpagereplay.replay.__file__
        args = ['python', replay_path, '--no-dns_forwarding', '--port', '8080', '--ssl_port', '8443', '--use_closest_match', '--log_level', 'warning']
        if record:
            args.append('--record')
        args.append(archive)

        self._process = subprocess.Popen(args)

    def wait_until_ready(self):
        for i in range(0, 3):
            try:
                connection = socket.create_connection(('localhost', '8080'), timeout=1)
                connection.close()
                return True
            except socket.error:
                time.sleep(1)
                continue
        return False

    def stop(self):
        if self._process:
            self._process.send_signal(signal.SIGINT)
            self._process.wait()
        self._process = None

    def __del__(self):
        self.stop()


class ReplayPerfTest(PageLoadingPerfTest):
    def __init__(self, port, test_name, path_or_url):
        super(ReplayPerfTest, self).__init__(port, test_name, path_or_url)

    def _start_replay_server(self, archive, record):
        try:
            return ReplayServer(archive, record)
        except OSError as error:
            if error.errno == errno.ENOENT:
                _log.error("Replay tests require web-page-replay.")
            else:
                raise error

    def prepare(self, time_out_ms):
        filesystem = self._port.host.filesystem
        path_without_ext = filesystem.splitext(self.path_or_url())[0]

        self._archive_path = filesystem.join(path_without_ext + '.wpr')
        self._expected_image_path = filesystem.join(path_without_ext + '-expected.png')
        self._url = filesystem.read_text_file(self.path_or_url()).split('\n')[0]

        if filesystem.isfile(self._archive_path) and filesystem.isfile(self._expected_image_path):
            _log.info("Replay ready for %s" % self._archive_path)
            return True

        _log.info("Preparing replay for %s" % self.test_name())

        driver = self._port.create_driver(worker_number=1, no_timeout=True)
        try:
            output = self.run_single(driver, self._archive_path, time_out_ms, record=True)
        finally:
            driver.stop()

        if not output or not filesystem.isfile(self._archive_path):
            _log.error("Failed to prepare a replay for %s" % self.test_name())
            return False

        _log.info("Prepared replay for %s" % self.test_name())

        return True

    def run_single(self, driver, url, time_out_ms, record=False):
        server = self._start_replay_server(self._archive_path, record)
        if not server:
            _log.error("Web page replay didn't start.")
            return None

        try:
            _log.debug("Waiting for Web page replay to start.")
            if not server.wait_until_ready():
                _log.error("Web page replay didn't start.")
                return None

            _log.debug("Web page replay started. Loading the page.")
            output = super(ReplayPerfTest, self).run_single(driver, self._url, time_out_ms, should_run_pixel_test=True)
            if self.run_failed(output):
                return None

            if not output.image:
                _log.error("Loading the page did not generate image results")
                _log.error(output.text)
                return None

            filesystem = self._port.host.filesystem
            dirname = filesystem.dirname(self._archive_path)
            filename = filesystem.split(self._archive_path)[1]
            writer = TestResultWriter(filesystem, self._port, dirname, filename)
            if record:
                writer.write_image_files(actual_image=None, expected_image=output.image)
            else:
                writer.write_image_files(actual_image=output.image, expected_image=None)

            return output
        finally:
            server.stop()


class PerfTestFactory(object):

    _pattern_map = [
        (re.compile(r'^inspector/'), ChromiumStylePerfTest),
        (re.compile(r'^PageLoad/'), PageLoadingPerfTest),
        (re.compile(r'(.+)\.replay$'), ReplayPerfTest),
    ]

    @classmethod
    def create_perf_test(cls, port, test_name, path):
        for (pattern, test_class) in cls._pattern_map:
            if pattern.match(test_name):
                return test_class(port, test_name, path)
        return PerfTest(port, test_name, path)