from __future__ import annotations

import base64
import io

import pytest
from PIL import Image

from mcp_sd15.errors import InvalidImageError
from mcp_sd15.images import decode_image, encode_png


def test_decodes_raw_base64_and_data_uri(image_base64: str) -> None:
    assert decode_image(image_base64).mode == "RGB"
    assert decode_image(f"data:image/png;base64,{image_base64}", mask=True).mode == "L"


@pytest.mark.parametrize("value", ["not base64!", "data:text/plain;base64,YQ==", ""])
def test_rejects_invalid_image_input(value: str) -> None:
    with pytest.raises(InvalidImageError):
        decode_image(value)


def test_rejects_non_image_base64() -> None:
    value = base64.b64encode(b"plain text").decode()
    with pytest.raises(InvalidImageError):
        decode_image(value)


def test_png_output_contains_metadata() -> None:
    data = encode_png(Image.new("RGB", (2, 2)), {"seed": 42, "mode": "test"})
    with Image.open(io.BytesIO(data)) as result:
        assert result.format == "PNG"
        assert result.info["seed"] == "42"