from __future__ import annotations

import concurrent.futures
import multiprocessing
import os
import sys
import time
from unittest import mock

import pytest

from pre_commit import parse_shebang
from pre_commit import xargs


def test_cpu_count_sched_getaffinity_exists():
    with mock.patch.object(
            os, 'sched_getaffinity', create=True, return_value=set(range(345)),
    ):
        assert xargs.cpu_count() == 345


@pytest.fixture
def no_sched_getaffinity():
    # Simulates an OS without os.sched_getaffinity available (mac/windows)
    # https://docs.python.org/3/library/os.html#interface-to-the-scheduler
    with mock.patch.object(
            os,
            'sched_getaffinity',
            create=True,
            side_effect=AttributeError,
    ):
        yield


def test_cpu_count_multiprocessing_cpu_count_implemented(no_sched_getaffinity):
    with mock.patch.object(multiprocessing, 'cpu_count', return_value=123):
        assert xargs.cpu_count() == 123


def test_cpu_count_multiprocessing_cpu_count_not_implemented(
        no_sched_getaffinity,
):
    with mock.patch.object(
            multiprocessing, 'cpu_count', side_effect=NotImplementedError,
    ):
        assert xargs.cpu_count() == 1


@pytest.mark.parametrize(
    ('env', 'expected'),
    (
        ({}, 0),
        ({b'x': b'1'}, 12),
        ({b'x': b'12'}, 13),
        ({b'x': b'1', b'y': b'2'}, 24),
    ),
)
def test_environ_size(env, expected):
    # normalize integer sizing
    assert xargs._environ_size(_env=env) == expected


@pytest.fixture
def win32_mock():
    with mock.patch.object(sys, 'getfilesystemencoding', return_value='utf-8'):
        with mock.patch.object(sys, 'platform', 'win32'):
            yield


@pytest.fixture
def linux_mock():
    with mock.patch.object(sys, 'getfilesystemencoding', return_value='utf-8'):
        with mock.patch.object(sys, 'platform', 'linux'):
            yield


def test_partition_trivial():
    assert xargs.partition(('cmd',), (), 1) == (('cmd',),)


def test_partition_simple():
    assert xargs.partition(('cmd',), ('foo',), 1) == (('cmd', 'foo'),)


def test_partition_limits():
    ret = xargs.partition(
        ('ninechars',), (
            # Just match the end (with spaces)
            '.' * 5, '.' * 4,
            # Just match the end (single arg)
            '.' * 10,
            # Goes over the end
            '.' * 5,
            '.' * 6,
        ),
        1,
        _max_length=21,
    )
    assert ret == (
        ('ninechars', '.' * 5, '.' * 4),
        ('ninechars', '.' * 10),
        ('ninechars', '.' * 5),
        ('ninechars', '.' * 6),
    )


def test_partition_limit_win32(win32_mock):
    cmd = ('ninechars',)
    # counted as half because of utf-16 encode
    varargs = ('😑' * 5,)
    ret = xargs.partition(cmd, varargs, 1, _max_length=21)
    assert ret == (cmd + varargs,)


def test_partition_limit_linux(linux_mock):
    cmd = ('ninechars',)
    varargs = ('😑' * 5,)
    ret = xargs.partition(cmd, varargs, 1, _max_length=31)
    assert ret == (cmd + varargs,)


def test_argument_too_long_with_large_unicode(linux_mock):
    cmd = ('ninechars',)
    varargs = ('😑' * 10,)  # 4 bytes * 10
    with pytest.raises(xargs.ArgumentTooLongError):
        xargs.partition(cmd, varargs, 1, _max_length=20)


def test_partition_target_concurrency():
    ret = xargs.partition(
        ('foo',), ('A',) * 22,
        4,
        _max_length=50,
    )
    assert ret == (
        ('foo',) + ('A',) * 6,
        ('foo',) + ('A',) * 6,
        ('foo',) + ('A',) * 6,
        ('foo',) + ('A',) * 4,
    )


def test_partition_target_concurrency_wont_make_tiny_partitions():
    ret = xargs.partition(
        ('foo',), ('A',) * 10,
        4,
        _max_length=50,
    )
    assert ret == (
        ('foo',) + ('A',) * 4,
        ('foo',) + ('A',) * 4,
        ('foo',) + ('A',) * 2,
    )


def test_argument_too_long():
    with pytest.raises(xargs.ArgumentTooLongError):
        xargs.partition(('a' * 5,), ('a' * 5,), 1, _max_length=10)


def test_xargs_smoke():
    ret, out = xargs.xargs(('echo',), ('hello', 'world'))
    assert ret == 0
    assert out.replace(b'\r\n', b'\n') == b'hello world\n'


exit_cmd = parse_shebang.normalize_cmd(('bash', '-c', 'exit $1', '--'))
# Abuse max_length to control the exit code
max_length = len(' '.join(exit_cmd)) + 3


def test_xargs_retcode_normal():
    ret, _ = xargs.xargs(exit_cmd, ('0',), _max_length=max_length)
    assert ret == 0

    ret, _ = xargs.xargs(exit_cmd, ('0', '1'), _max_length=max_length)
    assert ret == 1

    # takes the maximum return code
    ret, _ = xargs.xargs(exit_cmd, ('0', '5', '1'), _max_length=max_length)
    assert ret == 5


@pytest.mark.xfail(sys.platform == 'win32', reason='posix only')
def test_xargs_retcode_killed_by_signal():
    ret, _ = xargs.xargs(
        parse_shebang.normalize_cmd(('bash', '-c', 'kill -9 $$', '--')),
        ('foo', 'bar'),
    )
    assert ret == -9


def test_xargs_concurrency():
    bash_cmd = parse_shebang.normalize_cmd(('bash', '-c'))
    print_pid = ('sleep 0.5 && echo $$',)

    start = time.time()
    ret, stdout = xargs.xargs(
        bash_cmd, print_pid * 5,
        target_concurrency=5,
        _max_length=len(' '.join(bash_cmd + print_pid)) + 1,
    )
    elapsed = time.time() - start
    assert ret == 0
    pids = stdout.splitlines()
    assert len(pids) == 5
    # It would take 0.5*5=2.5 seconds to run all of these in serial, so if it
    # takes less, they must have run concurrently.
    assert elapsed < 2.5


def test_thread_mapper_concurrency_uses_threadpoolexecutor_map():
    with xargs._thread_mapper(10) as thread_map:
        _self = thread_map.__self__  # type: ignore
        assert isinstance(_self, concurrent.futures.ThreadPoolExecutor)


def test_thread_mapper_concurrency_uses_regular_map():
    with xargs._thread_mapper(1) as thread_map:
        assert thread_map is map


def test_xargs_propagate_kwargs_to_cmd():
    env = {'PRE_COMMIT_TEST_VAR': 'Pre commit is awesome'}
    cmd: tuple[str, ...] = ('bash', '-c', 'echo $PRE_COMMIT_TEST_VAR', '--')
    cmd = parse_shebang.normalize_cmd(cmd)

    ret, stdout = xargs.xargs(cmd, ('1',), env=env)
    assert ret == 0
    assert b'Pre commit is awesome' in stdout


@pytest.mark.xfail(sys.platform == 'win32', reason='posix only')
def test_xargs_color_true_makes_tty():
    retcode, out = xargs.xargs(
        (sys.executable, '-c', 'import sys; print(sys.stdout.isatty())'),
        ('1',),
        color=True,
    )
    assert retcode == 0
    assert out == b'True\n'


@pytest.mark.xfail(os.name == 'posix', reason='nt only')
@pytest.mark.parametrize('filename', ('t.bat', 't.cmd', 'T.CMD'))
def test_xargs_with_batch_files(tmpdir, filename):
    f = tmpdir.join(filename)
    f.write('echo it works\n')
    retcode, out = xargs.xargs((str(f),), ('x',) * 8192)
    assert retcode == 0, (retcode, out)
