"""Theme discovery must be a single source of truth."""
import json
from pathlib import Path
from app import core, theme_pro, theme_store

ROOT = Path(core.__file__).resolve().parent.parent

def test_discover_returns_builtin_themes_with_manifests():
    ids = core.discover_themes()
    for tid in ('automotive', 'industrial', 'corporate', 'minimal'):
        assert tid in ids
    for tid in ids:
        manifest = json.loads((ROOT / 'themes' / tid / 'manifest.json').read_text(encoding='utf-8'))
        assert manifest.get('id') == tid

def test_three_whitelists_agree():
    # Tripwire: the three names must stay the same object. Fails only if someone
    # reintroduces a hardcoded copy of the list anywhere.
    assert set(core.THEMES) == set(theme_pro.THEMES) == set(theme_store.BUILTIN)
    assert isinstance(core.THEMES, tuple)

def test_discover_skips_broken_theme_dirs(tmp_path, monkeypatch):
    themes = tmp_path / 'themes'
    good = themes / 'good-one'; good.mkdir(parents=True)
    (good / 'manifest.json').write_text(json.dumps({'id': 'good-one'}), encoding='utf-8')
    broken = themes / 'broken'; broken.mkdir()
    (broken / 'manifest.json').write_text('{not json', encoding='utf-8')
    mismatch = themes / 'mismatch'; mismatch.mkdir()
    (mismatch / 'manifest.json').write_text(json.dumps({'id': 'other-name'}), encoding='utf-8')
    no_manifest = themes / 'no-manifest'; no_manifest.mkdir()
    underscore = themes / '_shared'; underscore.mkdir()
    monkeypatch.setattr(core, 'ROOT', tmp_path)
    assert core.discover_themes() == ('good-one',)

def test_discover_fails_fast_when_themes_dir_missing(tmp_path, monkeypatch):
    monkeypatch.setattr(core, 'ROOT', tmp_path)
    import pytest
    with pytest.raises(RuntimeError, match='themes directory missing'):
        core.discover_themes()