import errno
import gzip
import os
import struct
import tempfile
import unittest
from io import BytesIO, StringIO, TextIOWrapper
from unittest import mock

from django.core.files import File
from django.core.files.base import ContentFile
from django.core.files.move import file_move_safe
from django.core.files.temp import NamedTemporaryFile
from django.core.files.uploadedfile import (
    InMemoryUploadedFile, SimpleUploadedFile, TemporaryUploadedFile,
    UploadedFile,
)

try:
    from PIL import Image
except ImportError:
    Image = None
else:
    from django.core.files import images


class FileTests(unittest.TestCase):
    def test_unicode_uploadedfile_name(self):
        uf = UploadedFile(name='¿Cómo?', content_type='text')
        self.assertIs(type(repr(uf)), str)

    def test_unicode_file_name(self):
        f = File(None, 'djángö')
        self.assertIs(type(repr(f)), str)

    def test_context_manager(self):
        orig_file = tempfile.TemporaryFile()
        base_file = File(orig_file)
        with base_file as f:
            self.assertIs(base_file, f)
            self.assertFalse(f.closed)
        self.assertTrue(f.closed)
        self.assertTrue(orig_file.closed)

    def test_open_resets_opened_file_to_start_and_returns_context_manager(self):
        file = File(BytesIO(b'content'))
        file.read()
        with file.open() as f:
            self.assertEqual(f.read(), b'content')

    def test_open_reopens_closed_file_and_returns_context_manager(self):
        temporary_file = tempfile.NamedTemporaryFile(delete=False)
        file = File(temporary_file)
        try:
            file.close()
            with file.open() as f:
                self.assertFalse(f.closed)
        finally:
            # remove temporary file
            os.unlink(file.name)

    def test_namedtemporaryfile_closes(self):
        """
        The symbol django.core.files.NamedTemporaryFile is assigned as
        a different class on different operating systems. In
        any case, the result should minimally mock some of the API of
        tempfile.NamedTemporaryFile from the Python standard library.
        """
        tempfile = NamedTemporaryFile()
        self.assertTrue(hasattr(tempfile, "closed"))
        self.assertFalse(tempfile.closed)

        tempfile.close()
        self.assertTrue(tempfile.closed)

    def test_file_mode(self):
        # Should not set mode to None if it is not present.
        # See #14681, stdlib gzip module crashes if mode is set to None
        file = SimpleUploadedFile("mode_test.txt", b"content")
        self.assertFalse(hasattr(file, 'mode'))
        gzip.GzipFile(fileobj=file)

    def test_file_iteration(self):
        """
        File objects should yield lines when iterated over.
        Refs #22107.
        """
        file = File(BytesIO(b'one\ntwo\nthree'))
        self.assertEqual(list(file), [b'one\n', b'two\n', b'three'])

    def test_file_iteration_windows_newlines(self):
        """
        #8149 - File objects with \r\n line endings should yield lines
        when iterated over.
        """
        f = File(BytesIO(b'one\r\ntwo\r\nthree'))
        self.assertEqual(list(f), [b'one\r\n', b'two\r\n', b'three'])

    def test_file_iteration_mac_newlines(self):
        """
        #8149 - File objects with \r line endings should yield lines
        when iterated over.
        """
        f = File(BytesIO(b'one\rtwo\rthree'))
        self.assertEqual(list(f), [b'one\r', b'two\r', b'three'])

    def test_file_iteration_mixed_newlines(self):
        f = File(BytesIO(b'one\rtwo\nthree\r\nfour'))
        self.assertEqual(list(f), [b'one\r', b'two\n', b'three\r\n', b'four'])

    def test_file_iteration_with_unix_newline_at_chunk_boundary(self):
        f = File(BytesIO(b'one\ntwo\nthree'))
        # Set chunk size to create a boundary after \n:
        # b'one\n...
        #        ^
        f.DEFAULT_CHUNK_SIZE = 4
        self.assertEqual(list(f), [b'one\n', b'two\n', b'three'])

    def test_file_iteration_with_windows_newline_at_chunk_boundary(self):
        f = File(BytesIO(b'one\r\ntwo\r\nthree'))
        # Set chunk size to create a boundary between \r and \n:
        # b'one\r\n...
        #        ^
        f.DEFAULT_CHUNK_SIZE = 4
        self.assertEqual(list(f), [b'one\r\n', b'two\r\n', b'three'])

    def test_file_iteration_with_mac_newline_at_chunk_boundary(self):
        f = File(BytesIO(b'one\rtwo\rthree'))
        # Set chunk size to create a boundary after \r:
        # b'one\r...
        #        ^
        f.DEFAULT_CHUNK_SIZE = 4
        self.assertEqual(list(f), [b'one\r', b'two\r', b'three'])

    def test_file_iteration_with_text(self):
        f = File(StringIO('one\ntwo\nthree'))
        self.assertEqual(list(f), ['one\n', 'two\n', 'three'])

    def test_readable(self):
        with tempfile.TemporaryFile() as temp, File(temp, name='something.txt') as test_file:
            self.assertTrue(test_file.readable())
        self.assertFalse(test_file.readable())

    def test_writable(self):
        with tempfile.TemporaryFile() as temp, File(temp, name='something.txt') as test_file:
            self.assertTrue(test_file.writable())
        self.assertFalse(test_file.writable())
        with tempfile.TemporaryFile('rb') as temp, File(temp, name='something.txt') as test_file:
            self.assertFalse(test_file.writable())

    def test_seekable(self):
        with tempfile.TemporaryFile() as temp, File(temp, name='something.txt') as test_file:
            self.assertTrue(test_file.seekable())
        self.assertFalse(test_file.seekable())

    def test_io_wrapper(self):
        content = "vive l'été\n"
        with tempfile.TemporaryFile() as temp, File(temp, name='something.txt') as test_file:
            test_file.write(content.encode())
            test_file.seek(0)
            wrapper = TextIOWrapper(test_file, 'utf-8', newline='\n')
            self.assertEqual(wrapper.read(), content)
            wrapper.write(content)
            wrapper.seek(0)
            self.assertEqual(wrapper.read(), content * 2)
            test_file = wrapper.detach()
            test_file.seek(0)
            self.assertEqual(test_file.read(), (content * 2).encode())


class NoNameFileTestCase(unittest.TestCase):
    """
    Other examples of unnamed files may be tempfile.SpooledTemporaryFile or
    urllib.urlopen()
    """
    def test_noname_file_default_name(self):
        self.assertIsNone(File(BytesIO(b'A file with no name')).name)

    def test_noname_file_get_size(self):
        self.assertEqual(File(BytesIO(b'A file with no name')).size, 19)


class ContentFileTestCase(unittest.TestCase):
    def test_content_file_default_name(self):
        self.assertIsNone(ContentFile(b"content").name)

    def test_content_file_custom_name(self):
        """
        The constructor of ContentFile accepts 'name' (#16590).
        """
        name = "I can have a name too!"
        self.assertEqual(ContentFile(b"content", name=name).name, name)

    def test_content_file_input_type(self):
        """
        ContentFile can accept both bytes and strings and the retrieved content
        is of the same type.
        """
        self.assertIsInstance(ContentFile(b"content").read(), bytes)
        self.assertIsInstance(ContentFile("español").read(), str)

    def test_open_resets_file_to_start_and_returns_context_manager(self):
        file = ContentFile(b'content')
        with file.open() as f:
            self.assertEqual(f.read(), b'content')
        with file.open() as f:
            self.assertEqual(f.read(), b'content')

    def test_size_changing_after_writing(self):
        """ContentFile.size changes after a write()."""
        f = ContentFile('')
        self.assertEqual(f.size, 0)
        f.write('Test ')
        f.write('string')
        self.assertEqual(f.size, 11)
        with f.open() as fh:
            self.assertEqual(fh.read(), 'Test string')


class InMemoryUploadedFileTests(unittest.TestCase):
    def test_open_resets_file_to_start_and_returns_context_manager(self):
        uf = InMemoryUploadedFile(StringIO('1'), '', 'test', 'text/plain', 1, 'utf8')
        uf.read()
        with uf.open() as f:
            self.assertEqual(f.read(), '1')


class TemporaryUploadedFileTests(unittest.TestCase):
    def test_extension_kept(self):
        """The temporary file name has the same suffix as the original file."""
        with TemporaryUploadedFile('test.txt', 'text/plain', 1, 'utf8') as temp_file:
            self.assertTrue(temp_file.file.name.endswith('.upload.txt'))


class DimensionClosingBug(unittest.TestCase):
    """
    get_image_dimensions() properly closes files (#8817)
    """
    @unittest.skipUnless(Image, "Pillow not installed")
    def test_not_closing_of_files(self):
        """
        Open files passed into get_image_dimensions() should stay opened.
        """
        empty_io = BytesIO()
        try:
            images.get_image_dimensions(empty_io)
        finally:
            self.assertTrue(not empty_io.closed)

    @unittest.skipUnless(Image, "Pillow not installed")
    def test_closing_of_filenames(self):
        """
        get_image_dimensions() called with a filename should closed the file.
        """
        # We need to inject a modified open() builtin into the images module
        # that checks if the file was closed properly if the function is
        # called with a filename instead of a file object.
        # get_image_dimensions will call our catching_open instead of the
        # regular builtin one.

        class FileWrapper:
            _closed = []

            def __init__(self, f):
                self.f = f

            def __getattr__(self, name):
                return getattr(self.f, name)

            def close(self):
                self._closed.append(True)
                self.f.close()

        def catching_open(*args):
            return FileWrapper(open(*args))

        images.open = catching_open
        try:
            images.get_image_dimensions(os.path.join(os.path.dirname(__file__), "test1.png"))
        finally:
            del images.open
        self.assertTrue(FileWrapper._closed)


class InconsistentGetImageDimensionsBug(unittest.TestCase):
    """
    get_image_dimensions() works properly after various calls
    using a file handler (#11158)
    """
    @unittest.skipUnless(Image, "Pillow not installed")
    def test_multiple_calls(self):
        """
        Multiple calls of get_image_dimensions() should return the same size.
        """
        img_path = os.path.join(os.path.dirname(__file__), "test.png")
        with open(img_path, 'rb') as fh:
            image = images.ImageFile(fh)
            image_pil = Image.open(fh)
            size_1 = images.get_image_dimensions(image)
            size_2 = images.get_image_dimensions(image)
        self.assertEqual(image_pil.size, size_1)
        self.assertEqual(size_1, size_2)

    @unittest.skipUnless(Image, "Pillow not installed")
    def test_bug_19457(self):
        """
        Regression test for #19457
        get_image_dimensions fails on some pngs, while Image.size is working good on them
        """
        img_path = os.path.join(os.path.dirname(__file__), "magic.png")
        size = images.get_image_dimensions(img_path)
        with open(img_path, 'rb') as fh:
            self.assertEqual(size, Image.open(fh).size)


@unittest.skipUnless(Image, "Pillow not installed")
class GetImageDimensionsTests(unittest.TestCase):

    def test_invalid_image(self):
        """
        get_image_dimensions() should return (None, None) for the dimensions of
        invalid images (#24441).

        brokenimg.png is not a valid image and it has been generated by:
        $ echo "123" > brokenimg.png
        """
        img_path = os.path.join(os.path.dirname(__file__), "brokenimg.png")
        with open(img_path, 'rb') as fh:
            size = images.get_image_dimensions(fh)
            self.assertEqual(size, (None, None))

    def test_valid_image(self):
        """
        get_image_dimensions() should catch struct.error while feeding the PIL
        Image parser (#24544).

        Emulates the Parser feed error. Since the error is raised on every feed
        attempt, the resulting image size should be invalid: (None, None).
        """
        img_path = os.path.join(os.path.dirname(__file__), "test.png")
        with mock.patch('PIL.ImageFile.Parser.feed', side_effect=struct.error):
            with open(img_path, 'rb') as fh:
                size = images.get_image_dimensions(fh)
                self.assertEqual(size, (None, None))

    def test_webp(self):
        img_path = os.path.join(os.path.dirname(__file__), 'test.webp')
        with open(img_path, 'rb') as fh:
            size = images.get_image_dimensions(fh)
        self.assertEqual(size, (540, 405))


class FileMoveSafeTests(unittest.TestCase):
    def test_file_move_overwrite(self):
        handle_a, self.file_a = tempfile.mkstemp()
        handle_b, self.file_b = tempfile.mkstemp()

        # file_move_safe() raises OSError if the destination file exists and
        # allow_overwrite is False.
        with self.assertRaises(FileExistsError):
            file_move_safe(self.file_a, self.file_b, allow_overwrite=False)

        # should allow it and continue on if allow_overwrite is True
        self.assertIsNone(file_move_safe(self.file_a, self.file_b, allow_overwrite=True))

        os.close(handle_a)
        os.close(handle_b)

    def test_file_move_copystat_cifs(self):
        """
        file_move_safe() ignores a copystat() EPERM PermissionError. This
        happens when the destination filesystem is CIFS, for example.
        """
        copystat_EACCES_error = PermissionError(errno.EACCES, 'msg')
        copystat_EPERM_error = PermissionError(errno.EPERM, 'msg')
        handle_a, self.file_a = tempfile.mkstemp()
        handle_b, self.file_b = tempfile.mkstemp()
        try:
            # This exception is required to reach the copystat() call in
            # file_safe_move().
            with mock.patch('django.core.files.move.os.rename', side_effect=OSError()):
                # An error besides EPERM isn't ignored.
                with mock.patch('django.core.files.move.copystat', side_effect=copystat_EACCES_error):
                    with self.assertRaises(PermissionError):
                        file_move_safe(self.file_a, self.file_b, allow_overwrite=True)
                # EPERM is ignored.
                with mock.patch('django.core.files.move.copystat', side_effect=copystat_EPERM_error):
                    self.assertIsNone(file_move_safe(self.file_a, self.file_b, allow_overwrite=True))
        finally:
            os.close(handle_a)
            os.close(handle_b)


class SpooledTempTests(unittest.TestCase):
    def test_in_memory_spooled_temp(self):
        with tempfile.SpooledTemporaryFile() as temp:
            temp.write(b"foo bar baz quux\n")
            django_file = File(temp, name="something.txt")
            self.assertEqual(django_file.size, 17)

    def test_written_spooled_temp(self):
        with tempfile.SpooledTemporaryFile(max_size=4) as temp:
            temp.write(b"foo bar baz quux\n")
            django_file = File(temp, name="something.txt")
            self.assertEqual(django_file.size, 17)
