"""Load optional legacy entity ID mappings for GREE Controller."""

from __future__ import annotations

import json
from pathlib import Path
from typing import Any

from homeassistant.core import HomeAssistant

from .const import ENTITY_MAP_FILE


def _load(path: Path) -> dict[str, str]:
    if not path.exists():
        return {}
    with path.open("r", encoding="utf-8") as handle:
        data: Any = json.load(handle)
    items = data.get("entities", []) if isinstance(data, dict) else []
    result: dict[str, str] = {}
    for item in items:
        if not isinstance(item, dict):
            continue
        device_id = str(item.get("device_id", "")).strip()
        entity_id = str(item.get("entity_id", "")).strip()
        if device_id and entity_id.startswith("climate."):
            result[device_id] = entity_id
    return result


async def async_load_entity_map(hass: HomeAssistant) -> dict[str, str]:
    """Load the optional mapping file without blocking Home Assistant's loop."""
    path = Path(hass.config.path(ENTITY_MAP_FILE))
    return await hass.async_add_executor_job(_load, path)