from __future__ import annotations

import os.path
import sys
from unittest import mock

import pytest

import pre_commit.constants as C
from pre_commit import lang_base
from pre_commit import parse_shebang
from pre_commit import xargs
from pre_commit.prefix import Prefix
from pre_commit.util import CalledProcessError


@pytest.fixture
def find_exe_mck():
    with mock.patch.object(parse_shebang, 'find_executable') as mck:
        yield mck


@pytest.fixture
def homedir_mck():
    def fake_expanduser(pth):
        assert pth == '~'
        return os.path.normpath('/home/me')

    with mock.patch.object(os.path, 'expanduser', fake_expanduser):
        yield


def test_exe_exists_does_not_exist(find_exe_mck, homedir_mck):
    find_exe_mck.return_value = None
    assert lang_base.exe_exists('ruby') is False


def test_exe_exists_exists(find_exe_mck, homedir_mck):
    find_exe_mck.return_value = os.path.normpath('/usr/bin/ruby')
    assert lang_base.exe_exists('ruby') is True


def test_exe_exists_false_if_shim(find_exe_mck, homedir_mck):
    find_exe_mck.return_value = os.path.normpath('/foo/shims/ruby')
    assert lang_base.exe_exists('ruby') is False


def test_exe_exists_false_if_homedir(find_exe_mck, homedir_mck):
    find_exe_mck.return_value = os.path.normpath('/home/me/somedir/ruby')
    assert lang_base.exe_exists('ruby') is False


def test_exe_exists_commonpath_raises_ValueError(find_exe_mck, homedir_mck):
    find_exe_mck.return_value = os.path.normpath('/usr/bin/ruby')
    with mock.patch.object(os.path, 'commonpath', side_effect=ValueError):
        assert lang_base.exe_exists('ruby') is True


def test_exe_exists_true_when_homedir_is_slash(find_exe_mck):
    find_exe_mck.return_value = os.path.normpath('/usr/bin/ruby')
    with mock.patch.object(os.path, 'expanduser', return_value=os.sep):
        assert lang_base.exe_exists('ruby') is True


def test_basic_get_default_version():
    assert lang_base.basic_get_default_version() == C.DEFAULT


def test_basic_health_check():
    assert lang_base.basic_health_check(Prefix('.'), 'default') is None


def test_failed_setup_command_does_not_unicode_error():
    script = (
        'import sys\n'
        "sys.stderr.buffer.write(b'\\x81\\xfe')\n"
        'raise SystemExit(1)\n'
    )

    # an assertion that this does not raise `UnicodeError`
    with pytest.raises(CalledProcessError):
        lang_base.setup_cmd(Prefix('.'), (sys.executable, '-c', script))


def test_environment_dir(tmp_path):
    ret = lang_base.environment_dir(Prefix(tmp_path), 'langenv', 'default')
    assert ret == f'{tmp_path}{os.sep}langenv-default'


def test_assert_version_default():
    with pytest.raises(AssertionError) as excinfo:
        lang_base.assert_version_default('lang', '1.2.3')
    msg, = excinfo.value.args
    assert msg == (
        'for now, pre-commit requires system-installed lang -- '
        'you selected `language_version: 1.2.3`'
    )


def test_assert_no_additional_deps():
    with pytest.raises(AssertionError) as excinfo:
        lang_base.assert_no_additional_deps('lang', ['hmmm'])
    msg, = excinfo.value.args
    assert msg == (
        'for now, pre-commit does not support additional_dependencies for '
        'lang -- '
        "you selected `additional_dependencies: ['hmmm']`"
    )


def test_no_env_noop(tmp_path):
    before = os.environ.copy()
    with lang_base.no_env(Prefix(tmp_path), '1.2.3'):
        inside = os.environ.copy()
    after = os.environ.copy()
    assert before == inside == after


@pytest.fixture
def cpu_count_mck():
    with mock.patch.object(xargs, 'cpu_count', return_value=4):
        yield


@pytest.mark.parametrize(
    ('var', 'expected'),
    (
        ('PRE_COMMIT_NO_CONCURRENCY', 1),
        ('TRAVIS', 2),
        (None, 4),
    ),
)
def test_target_concurrency(cpu_count_mck, var, expected):
    with mock.patch.dict(os.environ, {var: '1'} if var else {}, clear=True):
        assert lang_base.target_concurrency() == expected


def test_shuffled_is_deterministic():
    seq = [str(i) for i in range(10)]
    expected = ['4', '0', '5', '1', '8', '6', '2', '3', '7', '9']
    assert lang_base._shuffled(seq) == expected


def test_xargs_require_serial_is_not_shuffled():
    ret, out = lang_base.run_xargs(
        ('echo',), [str(i) for i in range(10)],
        require_serial=True,
        color=False,
    )
    assert ret == 0
    assert out.strip() == b'0 1 2 3 4 5 6 7 8 9'


def test_basic_run_hook(tmp_path):
    ret, out = lang_base.basic_run_hook(
        Prefix(tmp_path),
        'echo hi',
        ['hello'],
        ['file', 'file', 'file'],
        is_local=False,
        require_serial=False,
        color=False,
    )
    assert ret == 0
    out = out.replace(b'\r\n', b'\n')
    assert out == b'hi hello file file file\n'
