"""Selected map engine for newly generated HTML pages."""

from __future__ import annotations

import logging
from typing import Literal

logger = logging.getLogger(__name__)

HtmlMapEngine = Literal["echarts", "leaflet"]


def html_map_engine() -> HtmlMapEngine:
    """Return the admin-selected HTML map engine, defaulting to ECharts."""
    try:
        from deerflow.config.system_settings import load_system_settings

        engine = load_system_settings().html_map.engine
    except Exception:
        logger.debug("Failed to read the HTML map engine; using ECharts", exc_info=True)
        return "echarts"
    if engine == "leaflet":
        return "leaflet"
    return "echarts"