"""Boot volume snapshot after first Idle (once)."""

from __future__ import annotations

import time
from collections.abc import Callable
from typing import Any

from gpu_rent.config import Config
from gpu_rent.errors import CloudError
from gpu_rent.os_client import find_snapshot_by_name

Log = Callable[[str], None]


def ensure_boot_snapshot(
    conn,
    *,
    boot_volume_id: str | None,
    cfg: Config,
    log: Log,
) -> Any | None:
    """Create named boot snapshot if missing. Safe to call every up."""
    name = cfg.boot_snapshot_name
    existing = find_snapshot_by_name(conn, name)
    if existing:
        log(f"boot snapshot уже есть: {name}")
        return existing
    if not boot_volume_id:
        log("boot snapshot пропущен: нет boot_volume_id")
        return None
    log(f"создаю snapshot {name} с boot volume {boot_volume_id} (force)…")
    try:
        snap = conn.block_storage.create_snapshot(
            volume_id=boot_volume_id,
            name=name,
            description="gpu-rent first Idle; reuse for next boot",
            force=True,
        )
    except TypeError:
        try:
            snap = conn.block_storage.create_snapshot(
                volume_id=boot_volume_id,
                name=name,
                force=True,
            )
        except Exception as exc:
            raise CloudError(f"snapshot boot: {exc}") from exc
    except Exception as exc:
        raise CloudError(f"snapshot boot: {exc}") from exc

    snap_id = getattr(snap, "id", None)
    deadline = time.time() + 1800
    while time.time() < deadline:
        cur = conn.block_storage.get_snapshot(snap_id)
        status = (getattr(cur, "status", None) or "").lower()
        if status == "available":
            log(f"snapshot {name} ready ({snap_id})")
            return cur
        if status in {"error", "error_deleting"}:
            raise CloudError(f"snapshot {name} в статусе {status}")
        time.sleep(8)
    raise CloudError(f"snapshot {name} не стал available за 30 мин")