import psutil


def format_disks() -> str:
    parts = psutil.disk_partitions(all=False)
    lines = []

    skip_prefixes = (
        "/snap",
        "/proc",
        "/sys",
        "/run",
        "/boot/efi",
    )

    for p in parts:
        mp = p.mountpoint
        if mp.startswith(skip_prefixes):
            continue

        try:
            usage = psutil.disk_usage(mp)
        except PermissionError:
            continue

        icon = "🟢"
        if usage.percent > 90:
            icon = "🔴"
        elif usage.percent > 80:
            icon = "🟡"

        lines.append(
            f"{icon} **{mp}**: "
            f"{usage.used // (1024**3)} / {usage.total // (1024**3)} GiB "
            f"({usage.percent}%)"
        )

    if not lines:
        return "💽 Disks: n/a"

    return "💽 **Disks**\n" + "\n".join(lines)


def worst_disk_usage() -> tuple[int | None, str | None]:
    parts = psutil.disk_partitions(all=False)
    skip_prefixes = (
        "/snap",
        "/proc",
        "/sys",
        "/run",
        "/boot/efi",
    )

    worst_percent = None
    worst_mount = None

    for p in parts:
        mp = p.mountpoint
        if mp.startswith(skip_prefixes):
            continue
        try:
            usage = psutil.disk_usage(mp)
        except PermissionError:
            continue
        if worst_percent is None or usage.percent > worst_percent:
            worst_percent = int(usage.percent)
            worst_mount = mp

    return worst_percent, worst_mount