// Create a blank UEFI VM for PXE boot testing.
// Unlike cloud image VMs, these have an empty disk and boot from network.

import { execSync, spawnSync, type SpawnSyncReturns } from "node:child_process";
import { existsSync } from "node:fs";
import { join } from "node:path";
import { log } from "./libvirt.js";

const IMAGE_DIR = "/var/lib/libvirt/images";
const IS_ROOT = process.getuid?.() === 0;

function run(cmd: string, opts?: { timeout?: number }): string {
  const full = IS_ROOT ? cmd : `sudo ${cmd}`;
  return execSync(full, { encoding: "utf-8", stdio: "pipe", timeout: opts?.timeout ?? 60_000 });
}

function virsh(...args: string[]): SpawnSyncReturns<string> {
  const cmd = IS_ROOT ? "virsh" : "sudo";
  const finalArgs = IS_ROOT ? args : ["virsh", ...args];
  return spawnSync(cmd, finalArgs, { encoding: "utf-8", stdio: "pipe", timeout: 30_000 });
}

export interface PxeVmConfig {
  name: string;
  memory: number;       // MB
  vcpus: number;
  diskSize: number;     // GB
  network: string;      // libvirt network name
  arch?: "x86_64" | "aarch64";
}

/** Create a blank UEFI VM that PXE boots from the network. */
export function createPxeVm(config: PxeVmConfig): void {
  destroyPxeVm(config.name);

  const arch = config.arch ?? "x86_64";
  log(`Creating PXE VM: ${config.name} (${arch}, ${config.memory}MB RAM, ${config.vcpus} vCPU, ${config.diskSize}GB disk)`);

  // Create blank disk
  const diskPath = join(IMAGE_DIR, `${config.name}.qcow2`);
  run(`qemu-img create -f qcow2 "${diskPath}" ${config.diskSize}G`);

  // UEFI firmware paths (Fedora)
  if (arch === "aarch64") {
    const aavmf = "/usr/share/edk2/aarch64/QEMU_EFI.fd";
    if (!existsSync(aavmf)) {
      throw new Error(`AAVMF firmware not found at ${aavmf}. Install: sudo dnf install edk2-aarch64`);
    }
  } else {
    const ovmf = "/usr/share/edk2/ovmf/OVMF_CODE.fd";
    if (!existsSync(ovmf)) {
      throw new Error(`OVMF firmware not found at ${ovmf}. Install: sudo dnf install edk2-ovmf`);
    }
  }

  const virtInstallArgs = [
    "virt-install",
    `--name=${config.name}`,
    `--memory=${config.memory}`,
    `--vcpus=${config.vcpus}`,
    `--disk=path=${diskPath},format=qcow2,bus=virtio`,
    `--network=network=${config.network},model=virtio`,
    // UEFI firmware — required for PXE boot in modern mode
    `--boot=uefi,network`,
    // No OS to install — PXE provides everything
    "--os-variant=generic",
    "--noautoconsole",
    "--wait=0",
    // Graphics for debugging (VNC, connect with virt-viewer if needed)
    "--graphics=vnc,listen=127.0.0.1",
  ];

  if (arch === "aarch64") {
    virtInstallArgs.push("--arch=aarch64", "--machine=virt");
  }

  log(`Running: virt-install --name=${config.name} --boot=uefi,network ...`);
  run(virtInstallArgs.join(" "), { timeout: 30_000 });
  log(`PXE VM ${config.name} created and booting from network`);
}

/** Destroy a PXE VM and clean up its disk. */
export function destroyPxeVm(name: string): void {
  const result = virsh("dominfo", name);
  if (result.status !== 0) return;

  log(`Destroying PXE VM: ${name}`);
  virsh("destroy", name);
  virsh("undefine", name, "--remove-all-storage", "--nvram");
}

/** Get the MAC address of a VM's first NIC. */
export function getVmMac(name: string): string | null {
  const result = virsh("domiflist", name);
  if (result.status !== 0) return null;
  // Output format: Interface  Type  Source  Model  MAC
  const match = result.stdout.match(/([0-9a-f]{2}:[0-9a-f]{2}:[0-9a-f]{2}:[0-9a-f]{2}:[0-9a-f]{2}:[0-9a-f]{2})/i);
  return match ? match[1].toLowerCase() : null;
}

/** Reboot a VM (force off + start). */
export function rebootPxeVm(name: string): void {
  log(`Rebooting PXE VM: ${name}`);
  virsh("destroy", name);
  // Brief pause to let resources release
  spawnSync("sleep", ["2"]);
  virsh("start", name);
  log(`PXE VM ${name} restarted`);
}

/** Change VM boot order to disk first (skip PXE on next boot). */
export function setBootDisk(name: string): void {
  log(`Setting ${name} boot order to disk first`);
  virsh("destroy", name);
  spawnSync("sleep", ["2"]);
  // Get current XML, replace boot dev='network' with boot dev='hd'
  // This preserves UEFI loader/nvram settings (virt-xml --boot hd can break them)
  const dumpXml = virsh("dumpxml", name);
  if (dumpXml.status !== 0) throw new Error("Failed to dump VM XML");
  let xml = dumpXml.stdout;
  // Replace any <boot dev='...' /> entries with hd
  xml = xml.replace(/<boot dev='[^']*'\/>/g, "<boot dev='hd'/>");
  // If no boot dev entry, add one before </os>
  if (!xml.includes("<boot dev=")) {
    xml = xml.replace("</os>", "  <boot dev='hd'/>\n  </os>");
  }
  const xmlPath = `/tmp/${name}-bootfix.xml`;
  const { writeFileSync: writeFs, unlinkSync: unlinkFs } = require("node:fs") as typeof import("node:fs");
  writeFs(xmlPath, xml);
  run(`virsh define "${xmlPath}"`);
  try { unlinkFs(xmlPath); } catch { /* ignore */ }
  virsh("start", name);
  log(`${name} restarted with disk boot (UEFI preserved)`);
}

export interface IsoVmConfig {
  name: string;
  memory: number;       // MB
  vcpus: number;
  diskSize: number;     // GB
  network: string;      // libvirt network name
  isoPath: string;      // path to boot ISO
  arch?: "x86_64" | "aarch64";
}

/** Create a UEFI VM that boots from a CD-ROM ISO (not PXE). */
export function createIsoVm(config: IsoVmConfig): void {
  destroyPxeVm(config.name);

  const arch = config.arch ?? "x86_64";
  log(`Creating ISO boot VM: ${config.name} (${arch}, ${config.memory}MB RAM, ${config.vcpus} vCPU, ${config.diskSize}GB disk)`);

  // Create blank disk
  const diskPath = join(IMAGE_DIR, `${config.name}.qcow2`);
  run(`qemu-img create -f qcow2 "${diskPath}" ${config.diskSize}G`);

  const virtInstallArgs = [
    "virt-install",
    `--name=${config.name}`,
    `--memory=${config.memory}`,
    `--vcpus=${config.vcpus}`,
    `--disk=path=${diskPath},format=qcow2,bus=virtio`,
    // Boot ISO as CD-ROM
    `--disk=path=${config.isoPath},device=cdrom,readonly=on`,
    `--network=network=${config.network},model=virtio`,
    // UEFI firmware, boot from cdrom (not network)
    "--boot=uefi,cdrom",
    "--os-variant=generic",
    "--noautoconsole",
    "--wait=0",
    "--graphics=vnc,listen=127.0.0.1",
  ];

  if (arch === "aarch64") {
    virtInstallArgs.push("--arch=aarch64", "--machine=virt");
  }

  log(`Running: virt-install --name=${config.name} --boot=uefi,cdrom ...`);
  run(virtInstallArgs.join(" "), { timeout: 60_000 });
  log(`ISO boot VM ${config.name} created and booting from ISO`);
}