"""Tests for PPT_longPic function."""

from pathlib import Path
from unittest.mock import MagicMock, patch

import pytest

from pptopic.lib import PPT_longPic


def _make_img_mocks(tmp_path, num_images=1):
    """Build reusable mock objects for PPT_longPic tests.

    Returns (img_paths, mock_img, mock_canvas):
    - img_paths: real Path objects so ``sorted()`` works
    - mock_img: PIL Image mock with .size, .width, .height, .resize
    - mock_canvas: PIL Image.new mock
    """
    img_paths = [tmp_path / f"slide{i}.jpg" for i in range(1, num_images + 1)]
    mock_img = MagicMock()
    mock_img.mode = "RGB"
    mock_img.size = (100, 100)
    mock_img.width = 100
    mock_img.height = 100
    mock_img.resize.return_value = mock_img
    mock_canvas = MagicMock()
    return img_paths, mock_img, mock_canvas


class TestPPTLongPic:
    """Test PPT_longPic function."""

    # -- width variations --------------------------------------------------

    @pytest.mark.parametrize(
        "width,expected_size",
        [
            (None, (100, 100)),        # no scaling → uses img.size
            (50, (50, 50)),            # pixel width → (w, h*w//W)
            ("50%", (50, 50)),         # percentage → half
        ],
        ids=["none", "pixel", "percentage"],
    )
    @patch("pptopic.lib.convertPPT")
    def test_width_variations(self, mock_convert_ppt, width, expected_size, tmp_path):
        """PPT_longPic handles None / pixel / percentage width correctly."""
        img_paths, mock_img, mock_canvas = _make_img_mocks(tmp_path)

        mock_convert_ppt.return_value.__enter__.return_value = MagicMock()

        with patch("pptopic.lib.Path.glob", return_value=img_paths):
            with patch("pptopic.lib.Image.open") as mock_open:
                mock_open.return_value.__enter__.return_value = mock_img
                with patch("pptopic.lib.Image.new", return_value=mock_canvas):
                    PPT_longPic(tmp_path / "test.pptx", width=width, saveto=tmp_path)

        mock_canvas.save.assert_called_once()

    # -- saveName / saveto variations -------------------------------------

    @pytest.mark.parametrize(
        "save_name,saveto",
        [
            (None, None),                         # defaults: JPG, ppt parent dir
            ("output.jpg", None),                 # named, ppt parent dir
            (None, "."),                          # default name, custom dir
        ],
        ids=["defaults", "named", "custom_dir"],
    )
    @patch("pptopic.lib.convertPPT")
    def test_save_params(self, mock_convert_ppt, save_name, saveto, tmp_path):
        """PPT_longPic handles saveName / saveto combinations."""
        img_paths, mock_img, mock_canvas = _make_img_mocks(tmp_path)

        mock_convert_ppt.return_value.__enter__.return_value = MagicMock()

        with patch("pptopic.lib.Path.glob", return_value=img_paths):
            with patch("pptopic.lib.Image.open") as mock_open:
                mock_open.return_value.__enter__.return_value = mock_img
                with patch("pptopic.lib.Image.new", return_value=mock_canvas):
                    PPT_longPic(
                        tmp_path / "test.pptx",
                        saveName=save_name,
                        saveto=saveto if saveto else tmp_path,
                    )

        mock_canvas.save.assert_called_once()

    # -- error paths -------------------------------------------------------

    def test_invalid_image_type(self, tmp_path):
        ppt_file = tmp_path / "test.pptx"
        ppt_file.touch()
        with pytest.raises(ValueError, match="Unable to save this type"):
            PPT_longPic(ppt_file, saveName="output.bmp")

    @patch("pptopic.lib.convertPPT")
    def test_no_images_generated(self, mock_convert_ppt, tmp_path):
        ppt_file = tmp_path / "test.pptx"
        ppt_file.touch()
        mock_convert_ppt.return_value.__enter__.return_value = MagicMock()

        with patch("pptopic.lib.Path.glob", return_value=[]):
            with pytest.raises(ValueError, match="No images generated"):
                PPT_longPic(ppt_file)

    # -- multiple images ---------------------------------------------------

    @patch("pptopic.lib.convertPPT")
    def test_multiple_images(self, mock_convert_ppt, tmp_path):
        """PPT_longPic pastes every slide into the canvas."""
        img_paths, mock_img, mock_canvas = _make_img_mocks(tmp_path, num_images=3)

        mock_convert_ppt.return_value.__enter__.return_value = MagicMock()

        with patch("pptopic.lib.Path.glob", return_value=img_paths):
            with patch("pptopic.lib.Image.open") as mock_open:
                mock_open.return_value.__enter__.return_value = mock_img
                with patch("pptopic.lib.Image.new", return_value=mock_canvas):
                    PPT_longPic(tmp_path / "test.pptx", saveto=tmp_path)

        assert mock_canvas.paste.call_count == 3
        mock_canvas.save.assert_called_once()