/**
 * Integration tests run against a real hypervisor. Mocking it is forbidden — a test that
 * fakes the system under integration asserts that the fake behaves as expected, which is
 * the shape of test this project exists to stop shipping (novox/hq ADR 0034).
 *
 * Consequence, accepted: these are slow, and they need a machine that can raise scenarios.
 * They skip rather than fail where it cannot, so that a machine without a hypervisor gets
 * an honest "not run" instead of a green suite that checked nothing.
 */

import { isReachable, pools, supportedDrivers } from "../../src/incus/client.ts";
import { destroy, list } from "../../src/lifecycle/operate.ts";

export interface Capability {
  usable: boolean;
  why: string;
}

/** Can this machine run scenarios at all? Checked once, reported honestly. */
export async function labIsUsable(): Promise<Capability> {
  if (!(await isReachable())) {
    return {
      usable: false,
      why: "the incus daemon is not reachable as this user (try MESH_LAB_INCUS='sudo -n incus')",
    };
  }
  const drivers = await supportedDrivers();
  if (!drivers.some((d) => d === "btrfs" || d === "zfs")) {
    return { usable: false, why: "no copy-on-write driver — snapshots would be full copies" };
  }
  if (!(await pools()).some((p) => p.driver === "btrfs" || p.driver === "zfs")) {
    return { usable: false, why: "no pool uses a copy-on-write driver" };
  }
  return { usable: true, why: "" };
}

/** Tear down anything a test left behind, whether it passed or not. */
export async function destroyAll(prefix: string): Promise<void> {
  for (const instance of await list()) {
    if (instance.instanceId.startsWith(prefix)) {
      await destroy(instance.instanceId);
    }
  }
}