from __future__ import annotations

import pytest

from PIL import Image, ImagePalette

from .helper import assert_image_equal, assert_image_equal_tofile, hopper


def test_putpalette() -> None:
    def palette(mode):
        im = hopper(mode).copy()
        im.putpalette(list(range(256)) * 3)
        p = im.getpalette()
        if p:
            return im.mode, p[:10]
        return im.mode

    with pytest.raises(ValueError):
        palette("1")
    for mode in ["L", "LA", "P", "PA"]:
        assert palette(mode) == (
            "PA" if "A" in mode else "P",
            [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
        )
    with pytest.raises(ValueError):
        palette("I")
    with pytest.raises(ValueError):
        palette("F")
    with pytest.raises(ValueError):
        palette("RGB")
    with pytest.raises(ValueError):
        palette("RGBA")
    with pytest.raises(ValueError):
        palette("YCbCr")

    with Image.open("Tests/images/hopper_gray.jpg") as im:
        assert im.mode == "L"
        im.putpalette(list(range(256)) * 3)

    with Image.open("Tests/images/la.tga") as im:
        assert im.mode == "LA"
        im.putpalette(list(range(256)) * 3)


def test_imagepalette() -> None:
    im = hopper("P")
    im.putpalette(ImagePalette.negative())
    assert_image_equal_tofile(im.convert("RGB"), "Tests/images/palette_negative.png")

    im.putpalette(ImagePalette.random())

    im.putpalette(ImagePalette.sepia())
    assert_image_equal_tofile(im.convert("RGB"), "Tests/images/palette_sepia.png")

    im.putpalette(ImagePalette.wedge())
    assert_image_equal_tofile(im.convert("RGB"), "Tests/images/palette_wedge.png")


def test_putpalette_with_alpha_values() -> None:
    with Image.open("Tests/images/transparent.gif") as im:
        expected = im.convert("RGBA")

        palette = im.getpalette()
        transparency = im.info.pop("transparency")

        palette_with_alpha_values = []
        for i in range(256):
            color = palette[i * 3 : i * 3 + 3]
            alpha = 0 if i == transparency else 255
            palette_with_alpha_values += color + [alpha]
        im.putpalette(palette_with_alpha_values, "RGBA")

        assert_image_equal(im.convert("RGBA"), expected)


@pytest.mark.parametrize(
    "mode, palette",
    (
        ("RGBA", (1, 2, 3, 4)),
        ("RGBAX", (1, 2, 3, 4, 0)),
    ),
)
def test_rgba_palette(mode, palette) -> None:
    im = Image.new("P", (1, 1))
    im.putpalette(palette, mode)
    assert im.getpalette() == [1, 2, 3]
    assert im.palette.colors == {(1, 2, 3, 4): 0}


def test_empty_palette() -> None:
    im = Image.new("P", (1, 1))
    assert im.getpalette() == []


def test_undefined_palette_index() -> None:
    im = Image.new("P", (1, 1), 3)
    im.putpalette((1, 2, 3))
    assert im.convert("RGB").getpixel((0, 0)) == (0, 0, 0)