"""Tests for configuration loading."""

import pytest

from stemsplitter.config import Settings, get_settings


class TestSettings:
    def test_defaults(self):
        """Settings should provide sensible defaults."""
        s = Settings()
        assert s.output_format in ("WAV", "MP3", "FLAC")
        assert s.sample_rate == 44100
        assert s.normalization == 0.9
        assert s.web_port == 7860
        assert s.log_level == "WARNING"

    def test_env_override(self, monkeypatch):
        """Settings should pick up environment variable overrides."""
        monkeypatch.setenv("STEMSPLITTER_OUTPUT_FORMAT", "FLAC")
        monkeypatch.setenv("STEMSPLITTER_SAMPLE_RATE", "48000")
        monkeypatch.setenv("STEMSPLITTER_WEB_PORT", "9090")
        s = get_settings()
        assert s.output_format == "FLAC"
        assert s.sample_rate == 48000
        assert s.web_port == 9090

    def test_immutability(self):
        """Settings instances should be frozen."""
        s = Settings()
        with pytest.raises(AttributeError):
            s.output_dir = "/some/other/path"  # type: ignore

    def test_output_dir_default(self):
        """Default output_dir should be ./output."""
        s = Settings()
        assert s.output_dir == "./output"

    def test_model_defaults(self):
        """Default models should be set for both modes."""
        s = Settings()
        assert "mel_band_roformer" in s.default_2stem_model
        assert "htdemucs_ft" in s.default_4stem_model

    def test_get_settings_returns_fresh_instance(self, monkeypatch):
        """get_settings should create a new instance each time."""
        s1 = get_settings()
        monkeypatch.setenv("STEMSPLITTER_OUTPUT_FORMAT", "MP3")
        s2 = get_settings()
        assert s2.output_format == "MP3"
        assert s1 is not s2