"""Grow data volume upward (Cinder extend + resize2fs on VM)."""

from __future__ import annotations

import shlex
import time
from collections.abc import Callable

from gpu_rent.config import Config
from gpu_rent.errors import CloudError, GpuRentError
from gpu_rent.os_client import DATA_VOLUME_NAME, connect, find_volumes_by_name
from gpu_rent.ssh_ops import run_ssh
from gpu_rent.state import load_state, save_state

Log = Callable[[str], None]

_GROW_FS = r"""
set -euo pipefail
mnt=/mnt/swarm_data
src=$(findmnt -n -o SOURCE "$mnt" || true)
if [[ -z "$src" ]]; then
  echo "data volume not mounted at $mnt"
  exit 1
fi
if command -v resize2fs >/dev/null 2>&1; then
  resize2fs "$src"
elif command -v xfs_growfs >/dev/null 2>&1; then
  xfs_growfs "$mnt"
else
  echo "нет resize2fs/xfs_growfs"
  exit 1
fi
df -h "$mnt"
"""


def resize_data_volume(cfg: Config, new_gb: int, log: Log) -> None:
    if new_gb < 1:
        raise GpuRentError("--gb должен быть положительным")
    state = load_state()
    vol_id = state.data_volume_id
    conn = connect(cfg)
    if not vol_id:
        found = find_volumes_by_name(conn, DATA_VOLUME_NAME)
        if not found:
            raise CloudError("нет data volume — сначала gpu-rent up")
        vol_id = found[0].id
        state.data_volume_id = vol_id
        save_state(state)

    vol = conn.block_storage.get_volume(vol_id)
    current = int(getattr(vol, "size", 0) or 0)
    if new_gb < current:
        raise GpuRentError(
            f"вниз нельзя: сейчас {current} GB, запрошено {new_gb} GB. "
            "Selectel online resize только вверх."
        )
    if new_gb == current:
        log(f"data volume уже {current} GB")
        return

    log(f"Cinder extend {vol_id}: {current} → {new_gb} GB")
    try:
        conn.block_storage.extend_volume(vol, new_gb)
    except Exception:
        try:
            conn.block_storage.extend_volume(vol_id, new_gb)
        except Exception as exc:
            raise CloudError(f"extend volume: {exc}") from exc

    deadline = time.time() + 600
    while time.time() < deadline:
        cur = conn.block_storage.get_volume(vol_id)
        size = int(getattr(cur, "size", 0) or 0)
        status = (getattr(cur, "status", "") or "").lower()
        if size >= new_gb and status in {"available", "in-use"}:
            log(f"volume size={size} status={status}")
            break
        time.sleep(5)
    else:
        raise CloudError("volume не вырос за 10 мин")

    host = state.floating_ip
    if not host:
        log("нет FIP — FS на VM не расширяю; подними GPU и повтори resize2fs вручную")
        return

    log("resize2fs на /mnt/swarm_data…")
    quoted = shlex.quote(_GROW_FS)
    out = run_ssh(cfg, host, f"sudo -n bash -c {quoted}", timeout=180)
    log(out.strip() or "FS grown")