# 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/.

from __future__ import absolute_import, print_function, unicode_literals

import argparse
import logging
import os
import sys
import tempfile
from multiprocessing import cpu_count

import six

from concurrent.futures import ThreadPoolExecutor, as_completed, thread

import mozinfo
from mozfile import which
from manifestparser import TestManifest
from manifestparser import filters as mpf


from mach.decorators import CommandArgument, Command
from mach.requirements import MachEnvRequirements
from mach.util import UserError

here = os.path.abspath(os.path.dirname(__file__))


@Command("python", category="devenv", description="Run Python.")
@CommandArgument(
    "--no-virtualenv", action="store_true", help="Do not set up a virtualenv"
)
@CommandArgument(
    "--no-activate", action="store_true", help="Do not activate the virtualenv"
)
@CommandArgument(
    "--exec-file", default=None, help="Execute this Python file using `exec`"
)
@CommandArgument(
    "--ipython",
    action="store_true",
    default=False,
    help="Use ipython instead of the default Python REPL.",
)
@CommandArgument(
    "--requirements",
    default=None,
    help="Install this requirements file before running Python",
)
@CommandArgument("args", nargs=argparse.REMAINDER)
def python(
    command_context,
    no_virtualenv,
    no_activate,
    exec_file,
    ipython,
    requirements,
    args,
):
    # Avoid logging the command
    command_context.log_manager.terminal_handler.setLevel(logging.CRITICAL)

    # Note: subprocess requires native strings in os.environ on Windows.
    append_env = {"PYTHONDONTWRITEBYTECODE": str("1")}

    if requirements and no_virtualenv:
        raise UserError("Cannot pass both --requirements and --no-virtualenv.")

    if no_virtualenv:
        python_path = sys.executable
        requirements = MachEnvRequirements.from_requirements_definition(
            command_context.topsrcdir,
            False,
            True,
            os.path.join(
                command_context.topsrcdir, "build", "mach_virtualenv_packages.txt"
            ),
        )

        append_env["PYTHONPATH"] = os.pathsep.join(
            requirements.pths_as_absolute(command_context.topsrcdir)
        )
    else:
        command_context.virtualenv_manager.ensure()
        if not no_activate:
            command_context.virtualenv_manager.activate()
        python_path = command_context.virtualenv_manager.python_path
        if requirements:
            command_context.virtualenv_manager.install_pip_requirements(
                requirements, require_hashes=False
            )

    if exec_file:
        exec(open(exec_file).read())
        return 0

    if ipython:
        bindir = os.path.dirname(python_path)
        python_path = which("ipython", path=bindir)
        if not python_path:
            if not no_virtualenv:
                # Use `_run_pip` directly rather than `install_pip_package` to bypass
                # `req.check_if_exists()` which may detect a system installed ipython.
                command_context.virtualenv_manager._run_pip(["install", "ipython"])
                python_path = which("ipython", path=bindir)

            if not python_path:
                print("error: could not detect or install ipython")
                return 1

    return command_context.run_process(
        [python_path] + args,
        pass_thru=True,  # Allow user to run Python interactively.
        ensure_exit_code=False,  # Don't throw on non-zero exit code.
        python_unbuffered=False,  # Leave input buffered.
        append_env=append_env,
    )


@Command(
    "python-test",
    category="testing",
    virtualenv_name="python-test",
    description="Run Python unit tests with pytest.",
)
@CommandArgument(
    "-v", "--verbose", default=False, action="store_true", help="Verbose output."
)
@CommandArgument(
    "-j",
    "--jobs",
    default=None,
    type=int,
    help="Number of concurrent jobs to run. Default is the number of CPUs "
    "in the system.",
)
@CommandArgument(
    "-x",
    "--exitfirst",
    default=False,
    action="store_true",
    help="Runs all tests sequentially and breaks at the first failure.",
)
@CommandArgument(
    "--subsuite",
    default=None,
    help=(
        "Python subsuite to run. If not specified, all subsuites are run. "
        "Use the string `default` to only run tests without a subsuite."
    ),
)
@CommandArgument(
    "tests",
    nargs="*",
    metavar="TEST",
    help=(
        "Tests to run. Each test can be a single file or a directory. "
        "Default test resolution relies on PYTHON_UNITTEST_MANIFESTS."
    ),
)
@CommandArgument(
    "extra",
    nargs=argparse.REMAINDER,
    metavar="PYTEST ARGS",
    help=(
        "Arguments that aren't recognized by mach. These will be "
        "passed as it is to pytest"
    ),
)
def python_test(command_context, *args, **kwargs):
    try:
        tempdir = str(tempfile.mkdtemp(suffix="-python-test"))
        if six.PY2:
            os.environ[b"PYTHON_TEST_TMP"] = tempdir
        else:
            os.environ["PYTHON_TEST_TMP"] = tempdir
        return run_python_tests(command_context, *args, **kwargs)
    finally:
        import mozfile

        mozfile.remove(tempdir)


def run_python_tests(
    command_context,
    tests=None,
    test_objects=None,
    subsuite=None,
    verbose=False,
    jobs=None,
    exitfirst=False,
    extra=None,
    **kwargs
):

    command_context.activate_virtualenv()
    if test_objects is None:
        from moztest.resolve import TestResolver

        resolver = command_context._spawn(TestResolver)
        # If we were given test paths, try to find tests matching them.
        test_objects = resolver.resolve_tests(paths=tests, flavor="python")
    else:
        # We've received test_objects from |mach test|. We need to ignore
        # the subsuite because python-tests don't use this key like other
        # harnesses do and |mach test| doesn't realize this.
        subsuite = None

    mp = TestManifest()
    mp.tests.extend(test_objects)

    filters = []
    if subsuite == "default":
        filters.append(mpf.subsuite(None))
    elif subsuite:
        filters.append(mpf.subsuite(subsuite))

    tests = mp.active_tests(
        filters=filters,
        disabled=False,
        python=command_context.virtualenv_manager.version_info()[0],
        **mozinfo.info
    )

    if not tests:
        submsg = "for subsuite '{}' ".format(subsuite) if subsuite else ""
        message = (
            "TEST-UNEXPECTED-FAIL | No tests collected "
            + "{}(Not in PYTHON_UNITTEST_MANIFESTS?)".format(submsg)
        )
        command_context.log(logging.WARN, "python-test", {}, message)
        return 1

    parallel = []
    sequential = []
    os.environ.setdefault("PYTEST_ADDOPTS", "")

    if extra:
        os.environ["PYTEST_ADDOPTS"] += " " + " ".join(extra)

    installed_requirements = set()
    for test in tests:
        if (
            test.get("requirements")
            and test["requirements"] not in installed_requirements
        ):
            command_context.virtualenv_manager.install_pip_requirements(
                test["requirements"], quiet=True
            )
            installed_requirements.add(test["requirements"])

    if exitfirst:
        sequential = tests
        os.environ["PYTEST_ADDOPTS"] += " -x"
    else:
        for test in tests:
            if test.get("sequential"):
                sequential.append(test)
            else:
                parallel.append(test)

    jobs = jobs or cpu_count()

    return_code = 0

    def on_test_finished(result):
        output, ret, test_path = result

        for line in output:
            command_context.log(
                logging.INFO, "python-test", {"line": line.rstrip()}, "{line}"
            )

        if ret and not return_code:
            command_context.log(
                logging.ERROR,
                "python-test",
                {"test_path": test_path, "ret": ret},
                "Setting retcode to {ret} from {test_path}",
            )
        return return_code or ret

    with ThreadPoolExecutor(max_workers=jobs) as executor:
        futures = [
            executor.submit(_run_python_test, command_context, test, jobs, verbose)
            for test in parallel
        ]

        try:
            for future in as_completed(futures):
                return_code = on_test_finished(future.result())
        except KeyboardInterrupt:
            # Hack to force stop currently running threads.
            # https://gist.github.com/clchiou/f2608cbe54403edb0b13
            executor._threads.clear()
            thread._threads_queues.clear()
            raise

    for test in sequential:
        return_code = on_test_finished(
            _run_python_test(command_context, test, jobs, verbose)
        )
        if return_code and exitfirst:
            break

    command_context.log(
        logging.INFO,
        "python-test",
        {"return_code": return_code},
        "Return code from mach python-test: {return_code}",
    )
    return return_code


def _run_python_test(command_context, test, jobs, verbose):
    from mozprocess import ProcessHandler

    output = []

    def _log(line):
        # Buffer messages if more than one worker to avoid interleaving
        if jobs > 1:
            output.append(line)
        else:
            command_context.log(
                logging.INFO, "python-test", {"line": line.rstrip()}, "{line}"
            )

    file_displayed_test = []  # used as boolean

    def _line_handler(line):
        line = six.ensure_str(line)
        if not file_displayed_test:
            output = "Ran" in line or "collected" in line or line.startswith("TEST-")
            if output:
                file_displayed_test.append(True)

        # Hack to make sure treeherder highlights pytest failures
        if "FAILED" in line.rsplit(" ", 1)[-1]:
            line = line.replace("FAILED", "TEST-UNEXPECTED-FAIL")

        _log(line)

    _log(test["path"])
    python = command_context.virtualenv_manager.python_path
    cmd = [python, test["path"]]
    env = os.environ.copy()
    if six.PY2:
        env[b"PYTHONDONTWRITEBYTECODE"] = b"1"
    else:
        env["PYTHONDONTWRITEBYTECODE"] = "1"

    proc = ProcessHandler(
        cmd, env=env, processOutputLine=_line_handler, storeOutput=False
    )
    proc.run()

    return_code = proc.wait()

    if not file_displayed_test:
        _log(
            "TEST-UNEXPECTED-FAIL | No test output (missing mozunit.main() "
            "call?): {}".format(test["path"])
        )

    if verbose:
        if return_code != 0:
            _log("Test failed: {}".format(test["path"]))
        else:
            _log("Test passed: {}".format(test["path"]))

    return output, return_code, test["path"]