"""Narration themes: the icon/word/color mapping for progress lines.

A theme is a narrate(msg) -> rich-markup-string function plus its name;
the CLI picks one with --theme (default 'default'). Drop a module in
evalharness/themes/ and it registers itself.
"""
from typing import Callable

from ..eval.registry import EvalRegistry

THEME_REGISTRY = EvalRegistry('narration theme')


def register_theme(name: str):
    def decorator(fn: Callable[[str], str]):
        THEME_REGISTRY.register(name, fn)
        return fn

    return decorator


def get_theme(name: str = 'default'):
    return THEME_REGISTRY.get(name)


def _discover():
    import importlib
    import pkgutil

    for m in pkgutil.iter_modules(__path__):
        if m.name != '__init__':
            importlib.import_module(f'{__name__}.{m.name}')


_discover()