from io import BytesIO

from django.core.exceptions import RequestDataTooBig, TooManyFieldsSent
from django.core.handlers.wsgi import WSGIRequest
from django.test import SimpleTestCase
from django.test.client import FakePayload

TOO_MANY_FIELDS_MSG = 'The number of GET/POST parameters exceeded settings.DATA_UPLOAD_MAX_NUMBER_FIELDS.'
TOO_MUCH_DATA_MSG = 'Request body exceeded settings.DATA_UPLOAD_MAX_MEMORY_SIZE.'


class DataUploadMaxMemorySizeFormPostTests(SimpleTestCase):
    def setUp(self):
        payload = FakePayload('a=1&a=2;a=3\r\n')
        self.request = WSGIRequest({
            'REQUEST_METHOD': 'POST',
            'CONTENT_TYPE': 'application/x-www-form-urlencoded',
            'CONTENT_LENGTH': len(payload),
            'wsgi.input': payload,
        })

    def test_size_exceeded(self):
        with self.settings(DATA_UPLOAD_MAX_MEMORY_SIZE=12):
            with self.assertRaisesMessage(RequestDataTooBig, TOO_MUCH_DATA_MSG):
                self.request._load_post_and_files()

    def test_size_not_exceeded(self):
        with self.settings(DATA_UPLOAD_MAX_MEMORY_SIZE=13):
            self.request._load_post_and_files()

    def test_no_limit(self):
        with self.settings(DATA_UPLOAD_MAX_MEMORY_SIZE=None):
            self.request._load_post_and_files()


class DataUploadMaxMemorySizeMultipartPostTests(SimpleTestCase):
    def setUp(self):
        payload = FakePayload("\r\n".join([
            '--boundary',
            'Content-Disposition: form-data; name="name"',
            '',
            'value',
            '--boundary--'
            ''
        ]))
        self.request = WSGIRequest({
            'REQUEST_METHOD': 'POST',
            'CONTENT_TYPE': 'multipart/form-data; boundary=boundary',
            'CONTENT_LENGTH': len(payload),
            'wsgi.input': payload,
        })

    def test_size_exceeded(self):
        with self.settings(DATA_UPLOAD_MAX_MEMORY_SIZE=10):
            with self.assertRaisesMessage(RequestDataTooBig, TOO_MUCH_DATA_MSG):
                self.request._load_post_and_files()

    def test_size_not_exceeded(self):
        with self.settings(DATA_UPLOAD_MAX_MEMORY_SIZE=11):
            self.request._load_post_and_files()

    def test_no_limit(self):
        with self.settings(DATA_UPLOAD_MAX_MEMORY_SIZE=None):
            self.request._load_post_and_files()

    def test_file_passes(self):
        payload = FakePayload("\r\n".join([
            '--boundary',
            'Content-Disposition: form-data; name="file1"; filename="test.file"',
            '',
            'value',
            '--boundary--'
            ''
        ]))
        request = WSGIRequest({
            'REQUEST_METHOD': 'POST',
            'CONTENT_TYPE': 'multipart/form-data; boundary=boundary',
            'CONTENT_LENGTH': len(payload),
            'wsgi.input': payload,
        })
        with self.settings(DATA_UPLOAD_MAX_MEMORY_SIZE=1):
            request._load_post_and_files()
            self.assertIn('file1', request.FILES, "Upload file not present")


class DataUploadMaxMemorySizeGetTests(SimpleTestCase):
    def setUp(self):
        self.request = WSGIRequest({
            'REQUEST_METHOD': 'GET',
            'wsgi.input': BytesIO(b''),
            'CONTENT_LENGTH': 3,
        })

    def test_data_upload_max_memory_size_exceeded(self):
        with self.settings(DATA_UPLOAD_MAX_MEMORY_SIZE=2):
            with self.assertRaisesMessage(RequestDataTooBig, TOO_MUCH_DATA_MSG):
                self.request.body

    def test_size_not_exceeded(self):
        with self.settings(DATA_UPLOAD_MAX_MEMORY_SIZE=3):
            self.request.body

    def test_no_limit(self):
        with self.settings(DATA_UPLOAD_MAX_MEMORY_SIZE=None):
            self.request.body


class DataUploadMaxNumberOfFieldsGet(SimpleTestCase):

    def test_get_max_fields_exceeded(self):
        with self.settings(DATA_UPLOAD_MAX_NUMBER_FIELDS=1):
            with self.assertRaisesMessage(TooManyFieldsSent, TOO_MANY_FIELDS_MSG):
                request = WSGIRequest({
                    'REQUEST_METHOD': 'GET',
                    'wsgi.input': BytesIO(b''),
                    'QUERY_STRING': 'a=1&a=2;a=3',
                })
                request.GET['a']

    def test_get_max_fields_not_exceeded(self):
        with self.settings(DATA_UPLOAD_MAX_NUMBER_FIELDS=3):
            request = WSGIRequest({
                'REQUEST_METHOD': 'GET',
                'wsgi.input': BytesIO(b''),
                'QUERY_STRING': 'a=1&a=2;a=3',
            })
            request.GET['a']


class DataUploadMaxNumberOfFieldsMultipartPost(SimpleTestCase):
    def setUp(self):
        payload = FakePayload("\r\n".join([
            '--boundary',
            'Content-Disposition: form-data; name="name1"',
            '',
            'value1',
            '--boundary',
            'Content-Disposition: form-data; name="name2"',
            '',
            'value2',
            '--boundary--'
            ''
        ]))
        self.request = WSGIRequest({
            'REQUEST_METHOD': 'POST',
            'CONTENT_TYPE': 'multipart/form-data; boundary=boundary',
            'CONTENT_LENGTH': len(payload),
            'wsgi.input': payload,
        })

    def test_number_exceeded(self):
        with self.settings(DATA_UPLOAD_MAX_NUMBER_FIELDS=1):
            with self.assertRaisesMessage(TooManyFieldsSent, TOO_MANY_FIELDS_MSG):
                self.request._load_post_and_files()

    def test_number_not_exceeded(self):
        with self.settings(DATA_UPLOAD_MAX_NUMBER_FIELDS=2):
            self.request._load_post_and_files()

    def test_no_limit(self):
        with self.settings(DATA_UPLOAD_MAX_NUMBER_FIELDS=None):
            self.request._load_post_and_files()


class DataUploadMaxNumberOfFieldsFormPost(SimpleTestCase):
    def setUp(self):
        payload = FakePayload("\r\n".join(['a=1&a=2;a=3', '']))
        self.request = WSGIRequest({
            'REQUEST_METHOD': 'POST',
            'CONTENT_TYPE': 'application/x-www-form-urlencoded',
            'CONTENT_LENGTH': len(payload),
            'wsgi.input': payload,
        })

    def test_number_exceeded(self):
        with self.settings(DATA_UPLOAD_MAX_NUMBER_FIELDS=2):
            with self.assertRaisesMessage(TooManyFieldsSent, TOO_MANY_FIELDS_MSG):
                self.request._load_post_and_files()

    def test_number_not_exceeded(self):
        with self.settings(DATA_UPLOAD_MAX_NUMBER_FIELDS=3):
            self.request._load_post_and_files()

    def test_no_limit(self):
        with self.settings(DATA_UPLOAD_MAX_NUMBER_FIELDS=None):
            self.request._load_post_and_files()
