from __future__ import annotations

import tempfile
import warnings
from io import BytesIO
from pathlib import Path
from unittest.mock import MagicMock, patch
import unittest
import struct

import pytest

from PIL import Image, ImageSequence, SpiderImagePlugin

from .helper import assert_image_equal, hopper, is_pypy

TEST_FILE = "Tests/images/hopper.spider"


def test_sanity() -> None:
    with Image.open(TEST_FILE) as im:
        im.load()
        assert im.mode == "F"
        assert im.size == (128, 128)
        assert im.format == "SPIDER"


@pytest.mark.skipif(is_pypy(), reason="Requires CPython")
def test_unclosed_file() -> None:
    def open() -> None:
        im = Image.open(TEST_FILE)
        im.load()

    with pytest.warns(ResourceWarning):
        open()


def test_closed_file() -> None:
    with warnings.catch_warnings():
        im = Image.open(TEST_FILE)
        im.load()
        im.close()


def test_context_manager() -> None:
    with warnings.catch_warnings():
        with Image.open(TEST_FILE) as im:
            im.load()


def test_save(tmp_path: Path) -> None:
    # Arrange
    temp = str(tmp_path / "temp.spider")
    im = hopper()

    # Act
    im.save(temp, "SPIDER")

    # Assert
    with Image.open(temp) as im2:
        assert im2.mode == "F"
        assert im2.size == (128, 128)
        assert im2.format == "SPIDER"


def test_tempfile() -> None:
    # Arrange
    im = hopper()

    # Act
    with tempfile.TemporaryFile() as fp:
        im.save(fp, "SPIDER")

        # Assert
        fp.seek(0)
        with Image.open(fp) as reloaded:
            assert reloaded.mode == "F"
            assert reloaded.size == (128, 128)
            assert reloaded.format == "SPIDER"


def test_is_spider_image() -> None:
    assert SpiderImagePlugin.isSpiderImage(TEST_FILE)


def test_tell() -> None:
    # Arrange
    with Image.open(TEST_FILE) as im:
        # Act
        index = im.tell()

        # Assert
        assert index == 0


def test_n_frames() -> None:
    with Image.open(TEST_FILE) as im:
        assert im.n_frames == 1
        assert not im.is_animated


def test_load_image_series() -> None:
    # Arrange
    not_spider_file = "Tests/images/hopper.ppm"
    file_list = [TEST_FILE, not_spider_file, "path/not_found.ext"]

    # Act
    img_list = SpiderImagePlugin.loadImageSeries(file_list)

    # Assert
    assert len(img_list) == 1
    assert isinstance(img_list[0], Image.Image)
    assert img_list[0].size == (128, 128)


def test_load_image_series_no_input() -> None:
    # Arrange
    file_list = None

    # Act
    img_list = SpiderImagePlugin.loadImageSeries(file_list)

    # Assert
    assert img_list is None


def test_is_int_not_a_number() -> None:
    # Arrange
    not_a_number = "a"

    # Act
    ret = SpiderImagePlugin.isInt(not_a_number)

    # Assert
    assert ret == 0


def test_invalid_file() -> None:
    invalid_file = "Tests/images/invalid.spider"

    with pytest.raises(OSError):
        with Image.open(invalid_file):
            pass


def test_nonstack_file() -> None:
    with Image.open(TEST_FILE) as im:
        with pytest.raises(EOFError):
            im.seek(0)


def test_nonstack_dos() -> None:
    with Image.open(TEST_FILE) as im:
        for i, frame in enumerate(ImageSequence.Iterator(im)):
            assert i <= 1, "Non-stack DOS file test failed"


# for issue #4093
def test_odd_size() -> None:
    data = BytesIO()
    width = 100
    im = Image.new("F", (width, 64))
    im.save(data, format="SPIDER")

    data.seek(0)
    with Image.open(data) as im2:
        assert_image_equal(im, im2)


def test_seek_no_frame() -> None:
    with Image.open(TEST_FILE) as im:
        im.istack = 1
        im.seek(0)


def test_save_small_header() -> None:
    width, height = 10, 10
    im = Image.new("F", (width, height))

    fp = BytesIO()

    corrupted_header = [b'\x00' * 4] * 22

    with patch("PIL.SpiderImagePlugin.makeSpiderHeader", return_value=corrupted_header):
        try:
            im.save(fp, format="SPIDER")
        except OSError as e:
            assert str(e) == "Error creating Spider header"
        else:
            assert False, "Expected an OSError due to corrupted header"