import os
import tempfile
from pathlib import Path

import pytest
from PIL import Image

from photo_stitcher import core

def create_temp_image(color: tuple[int, int, int], size=(10, 10)) -> str:
    temp_dir = tempfile.mkdtemp()
    img_path = os.path.join(temp_dir, f"test_{color[0]}_{color[1]}_{color[2]}.png")
    img = Image.new("RGB", size, color=color)
    img.save(img_path)
    return img_path

def test_combine_images_creates_output(tmp_path: Path):
    img1 = create_temp_image((255, 0, 0))
    img2 = create_temp_image((0, 0, 255))
    output_file = tmp_path / "combined.tif"

    core.combine_images([img1, img2], str(output_file))

    assert output_file.exists(), "Output file should exist after combining."
    with Image.open(output_file) as result_img:
        assert result_img.size == (10, 10), "Output size should match input images."


def test_combine_images_invalid_input_raises(tmp_path: Path):
    output_file = tmp_path / "fail.tif"
    with pytest.raises((FileNotFoundError, ValueError, OSError)):
        core.combine_images(["non_existent.jpg"], str(output_file))


def test_combine_images_empty_list_raises(tmp_path: Path):
    output_file = tmp_path / "empty.tif"
    with pytest.raises(ValueError):
        core.combine_images([], str(output_file))


def test_combine_images_with_corrupt_file(tmp_path: Path):
    # Create a fake broken image file
    broken_path = tmp_path / "broken.jpg"
    broken_path.write_text("not an image")
    output_file = tmp_path / "out.tif"
    with pytest.raises((OSError, ValueError)):
        core.combine_images([str(broken_path)], str(output_file))