import logging
import os
import tempfile
import warnings
from unittest import TestCase

import pytest
import shortuuid

from dvc.repo import Repo as DvcRepo
from dvc.utils.fs import remove

logger = logging.getLogger("dvc")


class TestDirFixture:
    DATA_DIR = "data_dir"
    DATA_SUB_DIR = os.path.join(DATA_DIR, "data_sub_dir")
    DATA = os.path.join(DATA_DIR, "data")
    DATA_SUB = os.path.join(DATA_SUB_DIR, "data_sub")
    DATA_CONTENTS = DATA
    DATA_SUB_CONTENTS = DATA_SUB
    FOO = "foo"
    FOO_CONTENTS = FOO
    BAR = "bar"
    # NOTE: len(FOO_CONTENTS) must be != len(BAR_CONTENTS)
    #
    # Our state database relies on file mtime and file size to determine
    # that a file has changed. Usually, mtime is enough by itself but on
    # some filesystems like APFS on macOS mtime resolution is so bad,
    # that our tests can overwrite a file in that time window without dvc
    # being able to detect that, thus causing tests to fail. Usually,
    # in tests, we replace foo with bar, so we need to make sure that when we
    # modify a file in our tests, its content length changes.
    BAR_CONTENTS = BAR + "r"
    CODE = "code.py"
    CODE_CONTENTS = (
        "import sys\nimport shutil\n"
        "shutil.copyfile(sys.argv[1], sys.argv[2])"
    )
    UNICODE = "тест"
    UNICODE_CONTENTS = "проверка"

    def __init__(self):
        root_dir = self.mkdtemp()
        self._root_dir = os.path.realpath(root_dir)
        self._saved_dir = None

    @property
    def root_dir(self):
        return self._root_dir

    def _pushd(self, d):
        if not self._saved_dir:
            self._saved_dir = os.path.realpath(os.curdir)
        os.chdir(d)

    def _popd(self):
        os.chdir(self._saved_dir)
        self._saved_dir = None

    def create(self, name, contents):
        dname = os.path.dirname(name)
        if len(dname) > 0 and not os.path.isdir(dname):
            os.makedirs(dname)

        with open(name, "a", encoding="utf-8") as f:
            f.write(
                contents
                if isinstance(contents, str)
                else contents.decode("utf-8")
            )

    @staticmethod
    def mkdtemp(base_directory=None):
        prefix = f"dvc-test.{os.getpid()}."
        suffix = f".{shortuuid.uuid()}"
        return tempfile.mkdtemp(
            prefix=prefix, suffix=suffix, dir=base_directory
        )

    def setUp(self):
        self._pushd(self._root_dir)
        self.create(self.FOO, self.FOO_CONTENTS)
        self.create(self.BAR, self.BAR_CONTENTS)
        self.create(self.CODE, self.CODE_CONTENTS)
        os.mkdir(self.DATA_DIR)
        os.mkdir(self.DATA_SUB_DIR)
        self.create(self.DATA, self.DATA_CONTENTS)
        self.create(self.DATA_SUB, self.DATA_SUB_CONTENTS)
        self.create(self.UNICODE, self.UNICODE_CONTENTS)

    def tearDown(self):
        self._popd()
        try:
            remove(self._root_dir)
        except OSError as exc:
            # pylint: disable=no-member
            # We ignore this under Windows with a warning because it happened
            # to be really hard to trace all not properly closed files.
            #
            # Best guess so far is that gitpython is the culprit:
            # it opens files and uses __del__ to close them, which can happen
            # late in current pythons. TestGitFixture and TestDvcFixture try
            # to close that and it works on most of the tests, but not all.
            # Repos and thus git repos are created all over the dvc ;)
            if os.name == "nt" and exc.winerror == 32:
                warnings.warn("Failed to remove test dir: " + str(exc))
            else:
                raise


class TestGitFixture(TestDirFixture):
    N_RETRIES = 5

    def setUp(self):
        from scmrepo.git import Git

        super().setUp()
        self.git = Git.init(".")
        self.git.add_commit(self.CODE, message="add code")

    def tearDown(self):
        self.git.close()
        super().tearDown()


class TestDvcFixture(TestDirFixture):
    def setUp(self):
        super().setUp()
        self.dvc = DvcRepo.init(self.root_dir, no_scm=True)

    def tearDown(self):
        self.dvc.close()
        super().tearDown()


class TestDvcGitFixture(TestGitFixture):
    def setUp(self):
        super().setUp()
        self.dvc = DvcRepo.init(self.root_dir)
        self.dvc.scm.commit("init dvc")

    def tearDown(self):
        self.dvc.close()
        super().tearDown()


# NOTE: Inheritance order in the classes below is important.


class TestDir(TestDirFixture, TestCase):
    def __init__(self, methodName):
        TestDirFixture.__init__(self)
        TestCase.__init__(self, methodName)


class TestDvc(TestDvcFixture, TestCase):
    def __init__(self, methodName):
        TestDvcFixture.__init__(self)
        TestCase.__init__(self, methodName)
        self._caplog = None
        self._capsys = None

    @pytest.fixture(autouse=True)
    def inject_fixtures(self, caplog, capsys):
        self._caplog = caplog
        self._capsys = capsys


class TestDvcGit(TestDvcGitFixture, TestCase):
    def __init__(self, methodName):
        TestDvcGitFixture.__init__(self)
        TestCase.__init__(self, methodName)
        self._caplog = None

    @pytest.fixture(autouse=True)
    def inject_fixtures(self, caplog):
        self._caplog = caplog