#!/usr/bin/env python
# ***** BEGIN LICENSE BLOCK *****
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this file,
# You can obtain one at http://mozilla.org/MPL/2.0/.
# ***** END LICENSE BLOCK *****
"""
run talos tests in a virtualenv
"""

import copy
import io
import json
import multiprocessing
import os
import pprint
import re
import shutil
import subprocess
import sys

import six
from mozsystemmonitor.resourcemonitor import SystemResourceMonitor

import mozharness
from mozharness.base.config import parse_config_file
from mozharness.base.errors import PythonErrorList
from mozharness.base.log import CRITICAL, DEBUG, ERROR, INFO, WARNING, OutputParser
from mozharness.base.python import Python3Virtualenv
from mozharness.base.vcs.vcsbase import MercurialScript
from mozharness.mozilla.automation import (
    TBPL_FAILURE,
    TBPL_RETRY,
    TBPL_SUCCESS,
    TBPL_WARNING,
    TBPL_WORST_LEVEL_TUPLE,
)
from mozharness.mozilla.testing.codecoverage import (
    CodeCoverageMixin,
    code_coverage_config_options,
)
from mozharness.mozilla.testing.errors import TinderBoxPrintRe
from mozharness.mozilla.testing.testbase import TestingMixin, testing_config_options
from mozharness.mozilla.tooltool import TooltoolMixin

scripts_path = os.path.abspath(os.path.dirname(os.path.dirname(mozharness.__file__)))
external_tools_path = os.path.join(scripts_path, "external_tools")

TalosErrorList = PythonErrorList + [
    {"regex": re.compile(r"""run-as: Package '.*' is unknown"""), "level": DEBUG},
    {"substr": r"""FAIL: Graph server unreachable""", "level": CRITICAL},
    {"substr": r"""FAIL: Busted:""", "level": CRITICAL},
    {"substr": r"""FAIL: failed to cleanup""", "level": ERROR},
    {"substr": r"""erfConfigurator.py: Unknown error""", "level": CRITICAL},
    {"substr": r"""talosError""", "level": CRITICAL},
    {
        "regex": re.compile(r"""No machine_name called '.*' can be found"""),
        "level": CRITICAL,
    },
    {
        "substr": r"""No such file or directory: 'browser_output.txt'""",
        "level": CRITICAL,
        "explanation": "Most likely the browser failed to launch, or the test was otherwise "
        "unsuccessful in even starting.",
    },
]

GeckoProfilerSettings = (
    "gecko_profile_interval",
    "gecko_profile_entries",
    "gecko_profile_features",
    "gecko_profile_threads",
)

# TODO: check for running processes on script invocation


class TalosOutputParser(OutputParser):
    minidump_regex = re.compile(
        r'''talosError: "error executing: '(\S+) (\S+) (\S+)'"'''
    )
    RE_PERF_DATA = re.compile(r".*PERFHERDER_DATA:\s+(\{.*\})")
    worst_tbpl_status = TBPL_SUCCESS

    def __init__(self, **kwargs):
        super(TalosOutputParser, self).__init__(**kwargs)
        self.minidump_output = None
        self.found_perf_data = []

    def update_worst_log_and_tbpl_levels(self, log_level, tbpl_level):
        self.worst_log_level = self.worst_level(log_level, self.worst_log_level)
        self.worst_tbpl_status = self.worst_level(
            tbpl_level, self.worst_tbpl_status, levels=TBPL_WORST_LEVEL_TUPLE
        )

    def parse_single_line(self, line):
        """In Talos land, every line that starts with RETURN: needs to be
        printed with a TinderboxPrint:"""
        if line.startswith("RETURN:"):
            line.replace("RETURN:", "TinderboxPrint:")
        m = self.minidump_regex.search(line)
        if m:
            self.minidump_output = (m.group(1), m.group(2), m.group(3))

        m = self.RE_PERF_DATA.match(line)
        if m:
            self.found_perf_data.append(m.group(1))

        # now let's check if we should retry
        harness_retry_re = TinderBoxPrintRe["harness_error"]["retry_regex"]
        if harness_retry_re.search(line):
            self.critical(" %s" % line)
            self.update_worst_log_and_tbpl_levels(CRITICAL, TBPL_RETRY)
            return  # skip base parse_single_line

        if line.startswith("SUITE-START "):
            SystemResourceMonitor.begin_marker("suite", "")
        elif line.startswith("SUITE-END "):
            SystemResourceMonitor.end_marker("suite", "")
        elif line.startswith("TEST-"):
            part = line.split(" | ")
            if part[0] == "TEST-START":
                SystemResourceMonitor.begin_marker("test", part[1])
            elif part[0] in ("TEST-OK", "TEST-UNEXPECTED-ERROR"):
                SystemResourceMonitor.end_marker("test", part[1])
        elif line.startswith("Running cycle ") or line.startswith("PROCESS-CRASH "):
            SystemResourceMonitor.record_event(line)

        super(TalosOutputParser, self).parse_single_line(line)


class Talos(
    TestingMixin, MercurialScript, TooltoolMixin, Python3Virtualenv, CodeCoverageMixin
):
    """
    install and run Talos tests
    """

    config_options = (
        [
            [
                ["--use-talos-json"],
                {
                    "action": "store_true",
                    "dest": "use_talos_json",
                    "default": False,
                    "help": "Use talos config from talos.json",
                },
            ],
            [
                ["--suite"],
                {
                    "action": "store",
                    "dest": "suite",
                    "help": "Talos suite to run (from talos json)",
                },
            ],
            [
                ["--system-bits"],
                {
                    "action": "store",
                    "dest": "system_bits",
                    "type": "choice",
                    "default": "32",
                    "choices": ["32", "64"],
                    "help": "Testing 32 or 64 (for talos json plugins)",
                },
            ],
            [
                ["--add-option"],
                {
                    "action": "extend",
                    "dest": "talos_extra_options",
                    "default": None,
                    "help": "extra options to talos",
                },
            ],
            [
                ["--gecko-profile"],
                {
                    "dest": "gecko_profile",
                    "action": "store_true",
                    "default": False,
                    "help": "Whether or not to profile the test run and save the profile results",
                },
            ],
            [
                ["--gecko-profile-interval"],
                {
                    "dest": "gecko_profile_interval",
                    "type": "int",
                    "help": "The interval between samples taken by the profiler (milliseconds)",
                },
            ],
            [
                ["--gecko-profile-entries"],
                {
                    "dest": "gecko_profile_entries",
                    "type": "int",
                    "help": "How many samples to take with the profiler",
                },
            ],
            [
                ["--gecko-profile-features"],
                {
                    "dest": "gecko_profile_features",
                    "type": "str",
                    "default": None,
                    "help": "The features to enable in the profiler (comma-separated)",
                },
            ],
            [
                ["--gecko-profile-threads"],
                {
                    "dest": "gecko_profile_threads",
                    "type": "str",
                    "help": "Comma-separated list of threads to sample.",
                },
            ],
            [
                ["--gecko-profile-extra-threads"],
                {
                    "dest": "gecko_profile_extra_threads",
                    "type": "str",
                    "help": "Comma-separated list of extra threads to add to the default list of threads to profile.",
                },
            ],
            [
                ["--disable-e10s"],
                {
                    "dest": "e10s",
                    "action": "store_false",
                    "default": True,
                    "help": "Run without multiple processes (e10s).",
                },
            ],
            [
                ["--disable-fission"],
                {
                    "action": "store_false",
                    "dest": "fission",
                    "default": True,
                    "help": "Disable Fission (site isolation) in Gecko.",
                },
            ],
            [
                ["--project"],
                {
                    "dest": "project",
                    "type": "str",
                    "help": "The project branch we're running tests on. Used for "
                    "disabling/skipping tests.",
                },
            ],
            [
                ["--setpref"],
                {
                    "action": "append",
                    "metavar": "PREF=VALUE",
                    "dest": "extra_prefs",
                    "default": [],
                    "help": "Set a browser preference. May be used multiple times.",
                },
            ],
            [
                ["--skip-preflight"],
                {
                    "action": "store_true",
                    "dest": "skip_preflight",
                    "default": False,
                    "help": "skip preflight commands to prepare machine.",
                },
            ],
            [
                ["--screenshot-on-failure"],
                {
                    "action": "store_true",
                    "dest": "screenshot_on_failure",
                    "default": False,
                    "help": "Take a screenshot when the test fails.",
                },
            ],
            [
                ["--pdfPaintChunk"],
                {
                    "type": "int",
                    "dest": "pdfpaint_chunk",
                    "default": None,
                    "help": (
                        "Chunk of the pdfpaint test to run (each chunk runs at most 100 pdfs). "
                        "Defaults to None to run all the pdfs at the same time."
                    ),
                },
            ],
        ]
        + testing_config_options
        + copy.deepcopy(code_coverage_config_options)
    )

    def __init__(self, **kwargs):
        kwargs.setdefault("config_options", self.config_options)
        kwargs.setdefault(
            "all_actions",
            [
                "clobber",
                "download-and-extract",
                "populate-webroot",
                "create-virtualenv",
                "install",
                "run-tests",
            ],
        )
        kwargs.setdefault(
            "default_actions",
            [
                "clobber",
                "download-and-extract",
                "populate-webroot",
                "create-virtualenv",
                "install",
                "run-tests",
            ],
        )
        kwargs.setdefault("config", {})
        super(Talos, self).__init__(**kwargs)

        self.workdir = self.query_abs_dirs()["abs_work_dir"]  # convenience

        self.run_local = self.config.get("run_local")
        self.installer_url = self.config.get("installer_url")
        self.test_packages_url = self.config.get("test_packages_url")
        self.talos_json_url = self.config.get("talos_json_url")
        self.talos_json = self.config.get("talos_json")
        self.talos_json_config = self.config.get("talos_json_config")
        self.repo_path = self.config.get("repo_path")
        self.obj_path = self.config.get("obj_path")
        self.tests = None
        extra_opts = self.config.get("talos_extra_options", [])
        self.gecko_profile = (
            self.config.get("gecko_profile") or "--gecko-profile" in extra_opts
        )
        for setting in GeckoProfilerSettings:
            value = self.config.get(setting)
            arg = "--" + setting.replace("_", "-")
            if value is None:
                try:
                    value = extra_opts[extra_opts.index(arg) + 1]
                except ValueError:
                    pass  # Not found
            if value is not None:
                setattr(self, setting, value)
                if not self.gecko_profile:
                    self.warning("enabling Gecko profiler for %s setting!" % setting)
                    self.gecko_profile = True
        self.pagesets_name = None
        self.benchmark_zip = None
        self.webextensions_zip = None

    # We accept some configuration options from the try commit message in the format
    # mozharness: <options>
    # Example try commit message:
    #   mozharness: --gecko-profile try: <stuff>
    def query_gecko_profile_options(self):
        gecko_results = []
        # finally, if gecko_profile is set, we add that to the talos options
        if self.gecko_profile:
            gecko_results.append("--gecko-profile")
            for setting in GeckoProfilerSettings:
                value = getattr(self, setting, None)
                if value:
                    arg = "--" + setting.replace("_", "-")
                    gecko_results.extend([arg, str(value)])
        return gecko_results

    def query_abs_dirs(self):
        if self.abs_dirs:
            return self.abs_dirs
        abs_dirs = super(Talos, self).query_abs_dirs()
        abs_dirs["abs_blob_upload_dir"] = os.path.join(
            abs_dirs["abs_work_dir"], "blobber_upload_dir"
        )
        abs_dirs["abs_test_install_dir"] = os.path.join(
            abs_dirs["abs_work_dir"], "tests"
        )
        self.abs_dirs = abs_dirs
        return self.abs_dirs

    def query_talos_json_config(self):
        """Return the talos json config."""
        if self.talos_json_config:
            return self.talos_json_config
        if not self.talos_json:
            self.talos_json = os.path.join(self.talos_path, "talos.json")
        self.talos_json_config = parse_config_file(self.talos_json)
        self.info(pprint.pformat(self.talos_json_config))
        return self.talos_json_config

    def make_talos_domain(self, host):
        return host + "-talos"

    def split_path(self, path):
        result = []
        while True:
            path, folder = os.path.split(path)
            if folder:
                result.append(folder)
                continue
            elif path:
                result.append(path)
            break

        result.reverse()
        return result

    def merge_paths(self, lhs, rhs):
        backtracks = 0
        for subdir in rhs:
            if subdir == "..":
                backtracks += 1
            else:
                break
        return lhs[:-backtracks] + rhs[backtracks:]

    def replace_relative_iframe_paths(self, directory, filename):
        """This will find iframes with relative paths and replace them with
        absolute paths containing domains derived from the original source's
        domain. This helps us better simulate real-world cases for fission
        """
        if not filename.endswith(".html"):
            return

        directory_pieces = self.split_path(directory)
        while directory_pieces and directory_pieces[0] != "fis":
            directory_pieces = directory_pieces[1:]
        path = os.path.join(directory, filename)

        # XXX: ugh, is there a better way to account for multiple encodings than just
        # trying each of them?
        encodings = ["utf-8", "latin-1"]
        iframe_pattern = re.compile(r'(iframe.*")(\.\./.*\.html)"')
        for encoding in encodings:
            try:
                with io.open(path, "r", encoding=encoding) as f:
                    content = f.read()

                def replace_iframe_src(match):
                    src = match.group(2)
                    split = self.split_path(src)
                    merged = self.merge_paths(directory_pieces, split)
                    host = merged[3]
                    site_origin_hash = self.make_talos_domain(host)
                    new_url = 'http://%s/%s"' % (
                        site_origin_hash,
                        "/".join(merged),  # pylint --py3k: W1649
                    )
                    self.info(
                        "Replacing %s with %s in iframe inside %s"
                        % (match.group(2), new_url, path)
                    )
                    return match.group(1) + new_url

                content = re.sub(iframe_pattern, replace_iframe_src, content)
                with io.open(path, "w", encoding=encoding) as f:
                    f.write(content)
                break
            except UnicodeDecodeError:
                pass

    def query_pagesets_name(self):
        """Certain suites require external pagesets to be downloaded and
        extracted.
        """
        if self.pagesets_name:
            return self.pagesets_name
        if self.query_talos_json_config() and self.suite is not None:
            self.pagesets_name = self.talos_json_config["suites"][self.suite].get(
                "pagesets_name"
            )
            self.pagesets_name_manifest = "tp5n-pageset.manifest"
            return self.pagesets_name

    def query_benchmark_zip(self):
        """Certain suites require external benchmarks to be downloaded and
        extracted.
        """
        if self.benchmark_zip:
            return self.benchmark_zip
        if self.query_talos_json_config() and self.suite is not None:
            self.benchmark_zip = self.talos_json_config["suites"][self.suite].get(
                "benchmark_zip"
            )
            self.benchmark_zip_manifest = "jetstream-benchmark.manifest"
            return self.benchmark_zip

    def query_webextensions_zip(self):
        """Certain suites require external WebExtension sets to be downloaded and
        extracted.
        """
        if self.webextensions_zip:
            return self.webextensions_zip
        if self.query_talos_json_config() and self.suite is not None:
            self.webextensions_zip = self.talos_json_config["suites"][self.suite].get(
                "webextensions_zip"
            )
            self.webextensions_zip_manifest = "webextensions.manifest"
            return self.webextensions_zip

    def get_suite_from_test(self):
        """Retrieve the talos suite name from a given talos test name."""
        # running locally, single test name provided instead of suite; go through tests and
        # find suite name
        suite_name = None
        if self.query_talos_json_config():
            if "-a" in self.config["talos_extra_options"]:
                test_name_index = self.config["talos_extra_options"].index("-a") + 1
            if "--activeTests" in self.config["talos_extra_options"]:
                test_name_index = (
                    self.config["talos_extra_options"].index("--activeTests") + 1
                )
            if test_name_index < len(self.config["talos_extra_options"]):
                test_name = self.config["talos_extra_options"][test_name_index]
                for talos_suite in self.talos_json_config["suites"]:
                    if test_name in self.talos_json_config["suites"][talos_suite].get(
                        "tests"
                    ):
                        suite_name = talos_suite
            if not suite_name:
                # no suite found to contain the specified test, error out
                self.fatal("Test name is missing or invalid")
        else:
            self.fatal("Talos json config not found, cannot verify suite")
        return suite_name

    def query_suite_extra_prefs(self):
        if self.query_talos_json_config() and self.suite is not None:
            return self.talos_json_config["suites"][self.suite].get("extra_prefs", [])

        return []

    def validate_suite(self):
        """Ensure suite name is a valid talos suite."""
        if self.query_talos_json_config() and self.suite is not None:
            if self.suite not in self.talos_json_config.get("suites"):
                self.fatal(
                    "Suite '%s' is not valid (not found in talos json config)"
                    % self.suite
                )

    def talos_options(self, args=None, **kw):
        """return options to talos"""
        # binary path
        binary_path = self.binary_path or self.config.get("binary_path")
        if not binary_path:
            msg = """Talos requires a path to the binary.  You can specify binary_path or add
            download-and-extract to your action list."""
            self.fatal(msg)

        # talos options
        options = []
        # talos can't gather data if the process name ends with '.exe'
        if binary_path.endswith(".exe"):
            binary_path = binary_path[:-4]
        # options overwritten from **kw
        kw_options = {"executablePath": binary_path}
        if "suite" in self.config:
            kw_options["suite"] = self.config["suite"]
        if self.config.get("title"):
            kw_options["title"] = self.config["title"]
        if self.symbols_path:
            kw_options["symbolsPath"] = self.symbols_path
        if self.config.get("project", None):
            kw_options["project"] = self.config["project"]
        if self.config.get("pdfpaint_chunk", None):
            kw_options["pdfPaintChunk"] = str(self.config["pdfpaint_chunk"])

        kw_options.update(kw)
        # talos expects tests to be in the format (e.g.) 'ts:tp5:tsvg'
        tests = kw_options.get("activeTests")
        if tests and not isinstance(tests, six.string_types):
            tests = ":".join(tests)  # Talos expects this format
            kw_options["activeTests"] = tests
        for key, value in kw_options.items():
            options.extend(["--%s" % key, value])
        # configure profiling options
        options.extend(self.query_gecko_profile_options())
        # extra arguments
        if args is not None:
            options += args
        if "talos_extra_options" in self.config:
            options += self.config["talos_extra_options"]
        if self.config.get("code_coverage", False):
            options.extend(["--code-coverage"])
        if (
            self.config.get("screenshot_on_failure", False)
            or os.environ.get("MOZ_AUTOMATION", None) is not None
        ):
            options.extend(["--screenshot-on-failure"])

        # Add extra_prefs defined by individual test suites in talos.json
        extra_prefs = self.query_suite_extra_prefs()
        # Add extra_prefs from the configuration
        if self.config["extra_prefs"]:
            extra_prefs.extend(self.config["extra_prefs"])

        options.extend(["--setpref={}".format(p) for p in extra_prefs])

        # disabling fission can come from the --disable-fission cmd line argument; or in CI
        # it comes from a taskcluster transform which adds a --setpref for fission.autostart
        if (not self.config["fission"]) or "fission.autostart=false" in self.config[
            "extra_prefs"
        ]:
            options.extend(["--disable-fission"])

        return options

    def populate_webroot(self):
        """Populate the production test machines' webroots"""
        self.talos_path = os.path.join(
            self.query_abs_dirs()["abs_test_install_dir"], "talos"
        )

        # need to determine if talos pageset is required to be downloaded
        if self.config.get("run_local") and "talos_extra_options" in self.config:
            # talos initiated locally, get and verify test/suite from cmd line
            self.talos_path = os.path.dirname(self.talos_json)
            if (
                "-a" in self.config["talos_extra_options"]
                or "--activeTests" in self.config["talos_extra_options"]
            ):
                # test name (-a or --activeTests) specified, find out what suite it is a part of
                self.suite = self.get_suite_from_test()
            elif "--suite" in self.config["talos_extra_options"]:
                # --suite specified, get suite from cmd line and ensure is valid
                suite_name_index = (
                    self.config["talos_extra_options"].index("--suite") + 1
                )
                if suite_name_index < len(self.config["talos_extra_options"]):
                    self.suite = self.config["talos_extra_options"][suite_name_index]
                    self.validate_suite()
                else:
                    self.fatal("Suite name not provided")
        else:
            # talos initiated in production via mozharness
            self.suite = self.config["suite"]

        tooltool_artifacts = []
        src_talos_pageset_dest = os.path.join(self.talos_path, "talos", "tests")
        # unfortunately this path has to be short and can't be descriptive, because
        # on Windows we tend to already push the boundaries of the max path length
        # constraint. This will contain the tp5 pageset, but adjusted to have
        # absolute URLs on iframes for the purposes of better modeling things for
        # fission.
        src_talos_pageset_multidomain_dest = os.path.join(
            self.talos_path, "talos", "fis"
        )
        webextension_dest = os.path.join(self.talos_path, "talos", "webextensions")

        if self.query_pagesets_name():
            tooltool_artifacts.append(
                {
                    "name": self.pagesets_name,
                    "manifest": self.pagesets_name_manifest,
                    "dest": src_talos_pageset_dest,
                }
            )
            tooltool_artifacts.append(
                {
                    "name": self.pagesets_name,
                    "manifest": self.pagesets_name_manifest,
                    "dest": src_talos_pageset_multidomain_dest,
                    "postprocess": self.replace_relative_iframe_paths,
                }
            )

        if self.query_benchmark_zip():
            tooltool_artifacts.append(
                {
                    "name": self.benchmark_zip,
                    "manifest": self.benchmark_zip_manifest,
                    "dest": src_talos_pageset_dest,
                }
            )

        if self.query_webextensions_zip():
            tooltool_artifacts.append(
                {
                    "name": self.webextensions_zip,
                    "manifest": self.webextensions_zip_manifest,
                    "dest": webextension_dest,
                }
            )

        # now that have the suite name, check if artifact is required, if so download it
        # the --no-download option will override this
        for artifact in tooltool_artifacts:
            if "--no-download" not in self.config.get("talos_extra_options", []):
                self.info("Downloading %s with tooltool..." % artifact)

                archive = os.path.join(artifact["dest"], artifact["name"])
                output_dir_path = re.sub(r"\.zip$", "", archive)
                if not os.path.exists(archive):
                    manifest_file = os.path.join(self.talos_path, artifact["manifest"])
                    self.tooltool_fetch(
                        manifest_file,
                        output_dir=artifact["dest"],
                        cache=self.config.get("tooltool_cache"),
                    )
                    unzip = self.query_exe("unzip")
                    unzip_cmd = [unzip, "-q", "-o", archive, "-d", artifact["dest"]]
                    self.run_command(unzip_cmd, halt_on_failure=True)

                    if "postprocess" in artifact:
                        for subdir, dirs, files in os.walk(output_dir_path):
                            for file in files:
                                artifact["postprocess"](subdir, file)
                else:
                    self.info("%s already available" % artifact)

            else:
                self.info(
                    "Not downloading %s because the no-download option was specified"
                    % artifact
                )

        # if running webkit tests locally, need to copy webkit source into talos/tests
        if self.config.get("run_local") and (
            "stylebench" in self.suite or "motionmark" in self.suite
        ):
            self.get_webkit_source()

    def get_webkit_source(self):
        # in production the build system auto copies webkit source into place;
        # but when run locally we need to do this manually, so that talos can find it
        src = os.path.join(self.repo_path, "third_party", "webkit", "PerformanceTests")
        dest = os.path.join(
            self.talos_path, "talos", "tests", "webkit", "PerformanceTests"
        )

        if os.path.exists(dest):
            shutil.rmtree(dest)

        self.info("Copying webkit benchmarks from %s to %s" % (src, dest))
        try:
            shutil.copytree(src, dest)
        except Exception:
            self.critical("Error copying webkit benchmarks from %s to %s" % (src, dest))

    # Action methods. {{{1
    # clobber defined in BaseScript

    def download_and_extract(self, extract_dirs=None, suite_categories=None):
        # Use in-tree wptserve for Python 3.10 compatibility
        extract_dirs = [
            "tools/wptserve/*",
            "tools/wpt_third_party/h2/*",
            "tools/wpt_third_party/pywebsocket3/*",
        ]
        return super(Talos, self).download_and_extract(
            extract_dirs=extract_dirs, suite_categories=["common", "talos"]
        )

    def create_virtualenv(self, **kwargs):
        """VirtualenvMixin.create_virtualenv() assuemes we're using
        self.config['virtualenv_modules']. Since we are installing
        talos from its source, we have to wrap that method here."""
        # if virtualenv already exists, just add to path and don't re-install, need it
        # in path so can import jsonschema later when validating output for perfherder
        _virtualenv_path = self.config.get("virtualenv_path")

        _python_interp = self.query_exe("python")
        if "win" in self.platform_name() and os.path.exists(_python_interp):
            multiprocessing.set_executable(_python_interp)

        if self.run_local and os.path.exists(_virtualenv_path):
            self.info("Virtualenv already exists, skipping creation")

            if "win" in self.platform_name():
                _path = os.path.join(_virtualenv_path, "Lib", "site-packages")
            else:
                _path = os.path.join(
                    _virtualenv_path,
                    "lib",
                    os.path.basename(_python_interp),
                    "site-packages",
                )

            sys.path.append(_path)
            return

        # virtualenv doesn't already exist so create it
        # install mozbase first, so we use in-tree versions
        # Additionally, decide where to pull talos requirements from.
        if not self.run_local:
            mozbase_requirements = os.path.join(
                self.query_abs_dirs()["abs_test_install_dir"],
                "config",
                "mozbase_requirements.txt",
            )
            talos_requirements = os.path.join(self.talos_path, "requirements.txt")
        else:
            mozbase_requirements = os.path.join(
                os.path.dirname(self.talos_path),
                "config",
                "mozbase_source_requirements.txt",
            )
            talos_requirements = os.path.join(
                self.talos_path, "source_requirements.txt"
            )
        self.register_virtualenv_module(
            requirements=[mozbase_requirements],
            editable=True,
        )
        super(Talos, self).create_virtualenv()
        # talos in harness requires what else is
        # listed in talos requirements.txt file.
        self.install_module(requirements=[talos_requirements])

    def _validate_treeherder_data(self, parser):
        # late import is required, because install is done in create_virtualenv
        import jsonschema

        if len(parser.found_perf_data) != 1:
            self.critical(
                "PERFHERDER_DATA was seen %d times, expected 1."
                % len(parser.found_perf_data)
            )
            parser.update_worst_log_and_tbpl_levels(WARNING, TBPL_WARNING)
            return

        schema_path = os.path.join(
            external_tools_path, "performance-artifact-schema.json"
        )
        self.info("Validating PERFHERDER_DATA against %s" % schema_path)
        try:
            with open(schema_path) as f:
                schema = json.load(f)
            data = json.loads(parser.found_perf_data[0])
            jsonschema.validate(data, schema)
        except Exception:
            self.exception("Error while validating PERFHERDER_DATA")
            parser.update_worst_log_and_tbpl_levels(WARNING, TBPL_WARNING)

    def _artifact_perf_data(self, parser, dest):
        src = os.path.join(self.query_abs_dirs()["abs_work_dir"], "local.json")
        try:
            shutil.copyfile(src, dest)
        except Exception:
            self.critical("Error copying results %s to upload dir %s" % (src, dest))
            parser.update_worst_log_and_tbpl_levels(CRITICAL, TBPL_FAILURE)

    def run_tests(self, args=None, **kw):
        """run Talos tests"""

        # get talos options
        options = self.talos_options(args=args, **kw)

        # XXX temporary python version check
        python = self.query_python_path()
        self.run_command([python, "--version"])
        parser = TalosOutputParser(
            config=self.config, log_obj=self.log_obj, error_list=TalosErrorList
        )
        env = {}
        env["MOZ_UPLOAD_DIR"] = self.query_abs_dirs()["abs_blob_upload_dir"]
        if not self.run_local:
            env["MINIDUMP_STACKWALK"] = self.query_minidump_stackwalk()
            env["MOZ_FETCHES_DIR"] = os.environ.get("MOZ_FETCHES_DIR")
        else:
            env["MOZBUILD_PATH"] = self.config.get("mozbuild_path")
        env["MINIDUMP_SAVE_PATH"] = self.query_abs_dirs()["abs_blob_upload_dir"]
        env["RUST_BACKTRACE"] = "full"
        if not os.path.isdir(env["MOZ_UPLOAD_DIR"]):
            self.mkdir_p(env["MOZ_UPLOAD_DIR"])
        env = self.query_env(partial_env=env, log_level=INFO)
        # adjust PYTHONPATH to be able to use talos as a python package
        if "PYTHONPATH" in env:
            env["PYTHONPATH"] = self.talos_path + os.pathsep + env["PYTHONPATH"]
        else:
            env["PYTHONPATH"] = self.talos_path

        if self.repo_path is not None:
            env["MOZ_DEVELOPER_REPO_DIR"] = self.repo_path
        if self.obj_path is not None:
            env["MOZ_DEVELOPER_OBJ_DIR"] = self.obj_path

        # sets a timeout for how long talos should run without output
        output_timeout = self.config.get("talos_output_timeout", 3600)
        # run talos tests
        run_tests = os.path.join(self.talos_path, "talos", "run_tests.py")

        # Dynamically set the log level based on the talos config for consistency
        # throughout the test
        mozlog_opts = [f"--log-tbpl-level={self.config['log_level']}"]

        if not self.run_local and "suite" in self.config:
            fname_pattern = "%s_%%s.log" % self.config["suite"]
            mozlog_opts.append(
                "--log-errorsummary=%s"
                % os.path.join(env["MOZ_UPLOAD_DIR"], fname_pattern % "errorsummary")
            )

        def launch_in_debug_mode(cmdline):
            cmdline = set(cmdline)
            debug_opts = {"--debug", "--debugger", "--debugger_args"}

            return bool(debug_opts.intersection(cmdline))

        command = [python, run_tests] + options + mozlog_opts
        if launch_in_debug_mode(command):
            talos_process = subprocess.Popen(
                command, cwd=self.workdir, env=env, bufsize=0
            )
            talos_process.wait()
        else:
            self.return_code = self.run_command(
                command,
                cwd=self.workdir,
                output_timeout=output_timeout,
                output_parser=parser,
                env=env,
            )
        if parser.minidump_output:
            self.info("Looking at the minidump files for debugging purposes...")
            for item in parser.minidump_output:
                self.run_command(["ls", "-l", item])

        if self.return_code not in [0]:
            # update the worst log level and tbpl status
            log_level = ERROR
            tbpl_level = TBPL_FAILURE
            if self.return_code == 1:
                log_level = WARNING
                tbpl_level = TBPL_WARNING
            if self.return_code == 4:
                log_level = WARNING
                tbpl_level = TBPL_RETRY

            parser.update_worst_log_and_tbpl_levels(log_level, tbpl_level)
        elif "--no-upload-results" not in options:
            if not self.gecko_profile:
                self._validate_treeherder_data(parser)
                if not self.run_local:
                    # copy results to upload dir so they are included as an artifact
                    dest = os.path.join(env["MOZ_UPLOAD_DIR"], "perfherder-data.json")
                    self._artifact_perf_data(parser, dest)

        self.record_status(parser.worst_tbpl_status, level=parser.worst_log_level)
