# ABOUTME: Tests for configuration loading and wallpaper path resolution.
# ABOUTME: Verifies TOML parsing, fallback hierarchy, and default values.

from pathlib import Path
from unittest.mock import patch

import pytest

from moonset.config import Config, load_config, resolve_background_path


class TestLoadConfig:
    """Tests for TOML config loading."""

    def test_returns_default_config_when_no_files_exist(self) -> None:
        config = load_config(config_paths=[Path("/nonexistent")])
        assert config.background_path is None

    def test_reads_background_path_from_toml(self, tmp_path: Path) -> None:
        conf = tmp_path / "moonset.toml"
        conf.write_text('background_path = "/custom/wallpaper.jpg"\n')
        config = load_config(config_paths=[conf])
        assert config.background_path == "/custom/wallpaper.jpg"

    def test_later_paths_override_earlier(self, tmp_path: Path) -> None:
        conf1 = tmp_path / "first.toml"
        conf1.write_text('background_path = "/first.jpg"\n')
        conf2 = tmp_path / "second.toml"
        conf2.write_text('background_path = "/second.jpg"\n')
        config = load_config(config_paths=[conf1, conf2])
        assert config.background_path == "/second.jpg"

    def test_skips_missing_config_files(self, tmp_path: Path) -> None:
        conf = tmp_path / "exists.toml"
        conf.write_text('background_path = "/exists.jpg"\n')
        config = load_config(config_paths=[Path("/nonexistent"), conf])
        assert config.background_path == "/exists.jpg"

    def test_default_config_has_none_background(self) -> None:
        config = Config()
        assert config.background_path is None


class TestResolveBackgroundPath:
    """Tests for wallpaper path resolution fallback hierarchy."""

    def test_uses_config_path_when_file_exists(self, tmp_path: Path) -> None:
        wallpaper = tmp_path / "custom.jpg"
        wallpaper.touch()
        config = Config(background_path=str(wallpaper))
        assert resolve_background_path(config) == wallpaper

    def test_ignores_config_path_when_file_missing(self, tmp_path: Path) -> None:
        config = Config(background_path="/nonexistent/wallpaper.jpg")
        # Falls through to system or package fallback
        result = resolve_background_path(config)
        assert result is not None

    def test_uses_moonarch_wallpaper_as_second_fallback(self, tmp_path: Path) -> None:
        moonarch_wp = tmp_path / "wallpaper.jpg"
        moonarch_wp.touch()
        config = Config(background_path=None)
        with patch("moonset.config.MOONARCH_WALLPAPER", moonarch_wp):
            assert resolve_background_path(config) == moonarch_wp

    def test_uses_package_fallback_as_last_resort(self) -> None:
        config = Config(background_path=None)
        with patch("moonset.config.MOONARCH_WALLPAPER", Path("/nonexistent")):
            result = resolve_background_path(config)
            # Package fallback should always exist
            assert result is not None