import unittest
from io import BytesIO

from PIL import Image

from .helper import PillowTestCase, is_win32

# Limits for testing the leak
mem_limit = 1024 * 1048576
stack_size = 8 * 1048576
iterations = int((mem_limit / stack_size) * 2)
codecs = dir(Image.core)
test_file = "Tests/images/rgb_trns_ycbc.jp2"


@unittest.skipIf(is_win32(), "requires Unix or macOS")
class TestJpegLeaks(PillowTestCase):
    def setUp(self):
        if "jpeg2k_encoder" not in codecs or "jpeg2k_decoder" not in codecs:
            self.skipTest("JPEG 2000 support not available")

    def test_leak_load(self):
        from resource import setrlimit, RLIMIT_AS, RLIMIT_STACK

        setrlimit(RLIMIT_STACK, (stack_size, stack_size))
        setrlimit(RLIMIT_AS, (mem_limit, mem_limit))
        for _ in range(iterations):
            with Image.open(test_file) as im:
                im.load()

    def test_leak_save(self):
        from resource import setrlimit, RLIMIT_AS, RLIMIT_STACK

        setrlimit(RLIMIT_STACK, (stack_size, stack_size))
        setrlimit(RLIMIT_AS, (mem_limit, mem_limit))
        for _ in range(iterations):
            with Image.open(test_file) as im:
                im.load()
                test_output = BytesIO()
                im.save(test_output, "JPEG2000")
                test_output.seek(0)
                test_output.read()


if __name__ == "__main__":
    unittest.main()