"""ZFS operations for a site's web dataset."""
from __future__ import annotations

from datetime import datetime

from .config import Config, Site
from .runner import Runner


def web_dataset(cfg: Config, site: Site) -> str:
    return f"{cfg.pool}/customers/{site.customer}/{site.site}/web"


def customer_dataset(cfg: Config, customer: str) -> str:
    return f"{cfg.pool}/customers/{customer}"


def exists(runner: Runner, dataset: str) -> bool:
    if runner.dry_run:
        return False
    out = runner.run(["zfs", "list", "-H", "-o", "name", dataset],
                     check=False, capture=True)
    return dataset in out.split()


def create_web(runner: Runner, cfg: Config, site: Site) -> str:
    ds = web_dataset(cfg, site)
    if not exists(runner, ds):
        # -p creates the customer/site parent datasets too (root-owned, 755 —
        # suitable as the SFTP chroot). The web child is chowned by the sftp step.
        runner.run(["zfs", "create", "-p", ds])
    return ds


def snapshot(runner: Runner, dataset: str, tag: str | None = None) -> str:
    tag = tag or "auto-" + datetime.now().strftime("%Y%m%d-%H%M%S")
    name = f"{dataset}@{tag}"
    runner.run(["zfs", "snapshot", name])
    return name


def destroy(runner: Runner, dataset: str, *, recursive: bool = True) -> None:
    cmd = ["zfs", "destroy"]
    if recursive:
        cmd.append("-r")
    cmd.append(dataset)
    runner.run(cmd)