import glob

from app.sample import Sample

_PS = "/sys/class/power_supply"


def _read(path: str) -> str | None:
    try:
        with open(path) as f:
            return f.read().strip()
    except OSError:
        return None


def _supplies() -> list[tuple[str, str]]:
    out: list[tuple[str, str]] = []
    for p in sorted(glob.glob(f"{_PS}/*")):
        t = _read(f"{p}/type")
        if t:
            out.append((t.lower(), p))
    return out


def fill(s: Sample) -> None:
    try:
        supplies = _supplies()
        for t, p in supplies:
            if t == "battery" and _read(f"{p}/present") == "1":
                cap = _read(f"{p}/capacity")
                if cap is not None:
                    try:
                        s.battery = int(cap)
                    except ValueError:
                        pass
                    s.battery_status = _read(f"{p}/status")
                break
        for t, p in supplies:
            if t == "mains" and _read(f"{p}/online") == "1":
                s.ac_online = True
                break
        if s.ac_online is None:
            for t, p in supplies:
                if t == "usb" and _read(f"{p}/online") == "1":
                    s.ac_online = True
                    break
    except OSError:
        pass