import pytest
from PIL import Image, ImageSequence, TiffImagePlugin

from .helper import PillowTestCase, assert_image_equal, hopper, skip_unless_feature


class TestImageSequence(PillowTestCase):
    def test_sanity(self):

        test_file = self.tempfile("temp.im")

        im = hopper("RGB")
        im.save(test_file)

        seq = ImageSequence.Iterator(im)

        index = 0
        for frame in seq:
            assert_image_equal(im, frame)
            assert im.tell() == index
            index += 1

        assert index == 1

        with pytest.raises(AttributeError):
            ImageSequence.Iterator(0)

    def test_iterator(self):
        with Image.open("Tests/images/multipage.tiff") as im:
            i = ImageSequence.Iterator(im)
            for index in range(0, im.n_frames):
                assert i[index] == next(i)
            with pytest.raises(IndexError):
                i[index + 1]
            with pytest.raises(StopIteration):
                next(i)

    def test_iterator_min_frame(self):
        with Image.open("Tests/images/hopper.psd") as im:
            i = ImageSequence.Iterator(im)
            for index in range(1, im.n_frames):
                assert i[index] == next(i)

    def _test_multipage_tiff(self):
        with Image.open("Tests/images/multipage.tiff") as im:
            for index, frame in enumerate(ImageSequence.Iterator(im)):
                frame.load()
                assert index == im.tell()
                frame.convert("RGB")

    def test_tiff(self):
        self._test_multipage_tiff()

    @skip_unless_feature("libtiff")
    def test_libtiff(self):
        TiffImagePlugin.READ_LIBTIFF = True
        self._test_multipage_tiff()
        TiffImagePlugin.READ_LIBTIFF = False

    def test_consecutive(self):
        with Image.open("Tests/images/multipage.tiff") as im:
            firstFrame = None
            for frame in ImageSequence.Iterator(im):
                if firstFrame is None:
                    firstFrame = frame.copy()
            for frame in ImageSequence.Iterator(im):
                assert_image_equal(frame, firstFrame)
                break

    def test_palette_mmap(self):
        # Using mmap in ImageFile can require to reload the palette.
        with Image.open("Tests/images/multipage-mmap.tiff") as im:
            color1 = im.getpalette()[0:3]
            im.seek(0)
            color2 = im.getpalette()[0:3]
            assert color1 == color2

    def test_all_frames(self):
        # Test a single image
        with Image.open("Tests/images/iss634.gif") as im:
            ims = ImageSequence.all_frames(im)

            assert len(ims) == 42
            for i, im_frame in enumerate(ims):
                assert im_frame is not im

                im.seek(i)
                assert_image_equal(im, im_frame)

            # Test a series of images
            ims = ImageSequence.all_frames([im, hopper(), im])
            assert len(ims) == 85

            # Test an operation
            ims = ImageSequence.all_frames(im, lambda im_frame: im_frame.rotate(90))
            for i, im_frame in enumerate(ims):
                im.seek(i)
                assert_image_equal(im.rotate(90), im_frame)