from __future__ import annotations

from pathlib import Path

import struct
import pytest
from unittest.mock import Mock, patch
from PIL.BlpImagePlugin import _BLPBaseDecoder
from PIL.BlpImagePlugin import BLP1Decoder


from PIL import Image

from .helper import (
    assert_image_equal,
    assert_image_equal_tofile,
    assert_image_similar,
    hopper,
)


def test_load_blp1() -> None:
    with Image.open("Tests/images/blp/blp1_jpeg.blp") as im:
        assert_image_equal_tofile(im, "Tests/images/blp/blp1_jpeg.png")

    with Image.open("Tests/images/blp/blp1_jpeg2.blp") as im:
        im.load()

def test_load_blp2_raw() -> None:
    with Image.open("Tests/images/blp/blp2_raw.blp") as im:
        assert_image_equal_tofile(im, "Tests/images/blp/blp2_raw.png")


def test_load_blp2_dxt1() -> None:
    with Image.open("Tests/images/blp/blp2_dxt1.blp") as im:
        assert_image_equal_tofile(im, "Tests/images/blp/blp2_dxt1.png")


def test_load_blp2_dxt1a() -> None:
    with Image.open("Tests/images/blp/blp2_dxt1a.blp") as im:
        assert_image_equal_tofile(im, "Tests/images/blp/blp2_dxt1a.png")


def test_save(tmp_path: Path) -> None:
    f = str(tmp_path / "temp.blp")

    for version in ("BLP1", "BLP2"):
        im = hopper("P")
        im.save(f, blp_version=version)

        with Image.open(f) as reloaded:
            assert_image_equal(im.convert("RGB"), reloaded)

        with Image.open("Tests/images/transparent.png") as im:
            f = str(tmp_path / "temp.blp")
            im.convert("P").save(f, blp_version=version)

            with Image.open(f) as reloaded:
                assert_image_similar(im, reloaded, 8)

    im = hopper()
    with pytest.raises(ValueError):
        im.save(f)


@pytest.mark.parametrize(
    "test_file",
    [
        "Tests/images/timeout-060745d3f534ad6e4128c51d336ea5489182c69d.blp",
        "Tests/images/timeout-31c8f86233ea728339c6e586be7af661a09b5b98.blp",
        "Tests/images/timeout-60d8b7c8469d59fc9ffff6b3a3dc0faeae6ea8ee.blp",
        "Tests/images/timeout-8073b430977660cdd48d96f6406ddfd4114e69c7.blp",
        "Tests/images/timeout-bba4f2e026b5786529370e5dfe9a11b1bf991f07.blp",
        "Tests/images/timeout-d6ec061c4afdef39d3edf6da8927240bb07fe9b7.blp",
        "Tests/images/timeout-ef9112a065e7183fa7faa2e18929b03e44ee16bf.blp",
    ],
)
def test_crashes(test_file: str) -> None:
    with open(test_file, "rb") as f:
        with Image.open(f) as im:
            with pytest.raises(OSError):
                im.load()

def test_decode():
    # Create a mock instance of BLP1Decoder with 'RGB' as the mode
    decoder = BLP1Decoder('RGB')

    # Mock the _read_blp_header and _load methods to simulate normal execution
    with patch.object(decoder, '_read_blp_header', return_value=None), \
        patch.object(decoder, '_load', return_value=None):
        # Call the decode method and verify that it returns (-1, 0)
        assert decoder.decode(b'') == (-1, 0)

    # Mock the _read_blp_header and _load methods to raise a struct.error
    with patch.object(decoder, '_read_blp_header', side_effect=struct.error), \
        patch.object(decoder, '_load', side_effect=struct.error):

        # Call the decode method and verify that it raises an OSError with the expected message
        with pytest.raises(OSError, match="Truncated BLP file"):
            decoder.decode(b'')