from pathlib import Path
import re


PROJECT_DIR = Path(__file__).resolve().parents[1]


def iter_app_dirs():
    for p in PROJECT_DIR.iterdir():
        if not p.is_dir():
            continue
        if p.name.startswith('_'):
            continue
        if (p / '__init__.py').exists():
            yield p


TEMPLATE_EXPR = re.compile(r"{{\s*([^}]*)\s*}}")


def extract_exprs(html_path: Path):
    text = html_path.read_text(encoding='utf-8', errors='ignore')
    return TEMPLATE_EXPR.findall(text)


def test_results_templates_have_next_button():
    missing = []
    for app_dir in iter_app_dirs():
        results = app_dir / 'Results.html'
        if results.exists():
            text = results.read_text(encoding='utf-8', errors='ignore')
            if '{{ next_button }}' not in text:
                missing.append(app_dir.name)
    assert not missing, (
        "Missing '{{ next_button }}' in Results.html for apps: " + ", ".join(missing)
    )


def test_no_arithmetic_in_any_app_templates():
    offenders = []
    control = {
        'extends', 'block', 'endblock', 'include', 'include_sibling',
        'if', 'elif', 'else', 'endif', 'for', 'endfor',
        'formfields', 'next_button', 'chat', 'load', 'static'
    }
    for app_dir in iter_app_dirs():
        for html in app_dir.glob('*.html'):
            for expr in extract_exprs(html):
                head = expr.strip().split()[0] if expr.strip() else ''
                if head in control:
                    continue
                if any(op in expr for op in ('-', '*', '/', '+')):
                    offenders.append(f"{app_dir.name}/{html.name}: {expr.strip()}")
    assert not offenders, (
        'Unsupported arithmetic in template expressions found: ' + '; '.join(offenders)
    )