import pickle

from django.core.exceptions import ValidationError
from django.core.files.uploadedfile import SimpleUploadedFile
from django.forms import FileField
from django.test import SimpleTestCase


class FileFieldTest(SimpleTestCase):
    def test_filefield_1(self):
        f = FileField()
        with self.assertRaisesMessage(ValidationError, "'This field is required.'"):
            f.clean("")
        with self.assertRaisesMessage(ValidationError, "'This field is required.'"):
            f.clean("", "")
        self.assertEqual("files/test1.pdf", f.clean("", "files/test1.pdf"))
        with self.assertRaisesMessage(ValidationError, "'This field is required.'"):
            f.clean(None)
        with self.assertRaisesMessage(ValidationError, "'This field is required.'"):
            f.clean(None, "")
        self.assertEqual("files/test2.pdf", f.clean(None, "files/test2.pdf"))
        no_file_msg = "'No file was submitted. Check the encoding type on the form.'"
        file = SimpleUploadedFile(None, b"")
        file._name = ""
        with self.assertRaisesMessage(ValidationError, no_file_msg):
            f.clean(file)
        with self.assertRaisesMessage(ValidationError, no_file_msg):
            f.clean(file, "")
        self.assertEqual("files/test3.pdf", f.clean(None, "files/test3.pdf"))
        with self.assertRaisesMessage(ValidationError, no_file_msg):
            f.clean("some content that is not a file")
        with self.assertRaisesMessage(
            ValidationError, "'The submitted file is empty.'"
        ):
            f.clean(SimpleUploadedFile("name", None))
        with self.assertRaisesMessage(
            ValidationError, "'The submitted file is empty.'"
        ):
            f.clean(SimpleUploadedFile("name", b""))
        self.assertEqual(
            SimpleUploadedFile,
            type(f.clean(SimpleUploadedFile("name", b"Some File Content"))),
        )
        self.assertIsInstance(
            f.clean(
                SimpleUploadedFile(
                    "我隻氣墊船裝滿晒鱔.txt", "मेरी मँडराने वाली नाव सर्पमीनों से भरी ह".encode()
                )
            ),
            SimpleUploadedFile,
        )
        self.assertIsInstance(
            f.clean(
                SimpleUploadedFile("name", b"Some File Content"), "files/test4.pdf"
            ),
            SimpleUploadedFile,
        )

    def test_filefield_2(self):
        f = FileField(max_length=5)
        with self.assertRaisesMessage(
            ValidationError,
            "'Ensure this filename has at most 5 characters (it has 18).'",
        ):
            f.clean(SimpleUploadedFile("test_maxlength.txt", b"hello world"))
        self.assertEqual("files/test1.pdf", f.clean("", "files/test1.pdf"))
        self.assertEqual("files/test2.pdf", f.clean(None, "files/test2.pdf"))
        self.assertIsInstance(
            f.clean(SimpleUploadedFile("name", b"Some File Content")),
            SimpleUploadedFile,
        )

    def test_filefield_3(self):
        f = FileField(allow_empty_file=True)
        self.assertIsInstance(
            f.clean(SimpleUploadedFile("name", b"")), SimpleUploadedFile
        )

    def test_filefield_changed(self):
        """
        The value of data will more than likely come from request.FILES. The
        value of initial data will likely be a filename stored in the database.
        Since its value is of no use to a FileField it is ignored.
        """
        f = FileField()

        # No file was uploaded and no initial data.
        self.assertFalse(f.has_changed("", None))

        # A file was uploaded and no initial data.
        self.assertTrue(
            f.has_changed("", {"filename": "resume.txt", "content": "My resume"})
        )

        # A file was not uploaded, but there is initial data
        self.assertFalse(f.has_changed("resume.txt", None))

        # A file was uploaded and there is initial data (file identity is not dealt
        # with here)
        self.assertTrue(
            f.has_changed(
                "resume.txt", {"filename": "resume.txt", "content": "My resume"}
            )
        )

    def test_disabled_has_changed(self):
        f = FileField(disabled=True)
        self.assertIs(f.has_changed("x", "y"), False)

    def test_file_picklable(self):
        self.assertIsInstance(pickle.loads(pickle.dumps(FileField())), FileField)