import { Agent } from 'undici';

// Read-only Proxmox storage + capacity health for the Sacred Valley card. Same
// PVEAuditor token as the cluster card (PROXMOX_RO_TOKEN). Surfaces the two things
// that have actually bitten this homelab and were previously invisible:
//   1. a ZFS pool dropping out (the donatello/leonardo SATA-bus incident) — seen as
//      a zfspool storage whose status is no longer 'available'.
//   2. a container rootfs filling up (mediastack hitting 95%) — per-LXC disk/maxdisk.

let insecure;
function tlsDispatcher() {
  if (process.env.PROXMOX_INSECURE_TLS !== '1') return undefined;
  insecure ??= new Agent({ connect: { rejectUnauthorized: false } });
  return insecure;
}

async function pveGet(path, { apiUrl, token, fetchImpl = fetch }) {
  const res = await fetchImpl(`${apiUrl}/api2/json${path}`, {
    headers: { Authorization: `PVEAPIToken=${token}` },
    dispatcher: tlsDispatcher()
  });
  if (!res.ok) throw new Error(`pve ${path} -> ${res.status}`);
  return (await res.json())?.data ?? [];
}

export const WARN = 80, CRIT = 90;
const pct = (used, total) => (total > 0 ? Math.round((used / total) * 100) : null);
const sev = p => (p == null ? 'ok' : p >= CRIT ? 'crit' : p >= WARN ? 'warn' : 'ok');
const worstOf = items => items.reduce(
  (w, x) => (x.status === 'crit' || w === 'crit') ? 'crit' : (x.status === 'warn' || w === 'warn') ? 'warn' : 'ok', 'ok');

// Pure: fold /nodes/*/disks/zfs + /cluster/resources(storage,vm) into the card shape.
export function normalizeStorage(storageRes = [], vmRes = [], zfsByNode = {}) {
  // Imported ZFS pools (health + usage)
  const pools = [];
  for (const [node, list] of Object.entries(zfsByNode)) {
    for (const z of (list || [])) {
      const p = pct(z.alloc, z.size);
      pools.push({
        name: z.name, node, health: z.health, used: z.alloc, total: z.size, pct: p,
        status: z.health !== 'ONLINE' ? 'crit' : sev(p)
      });
    }
  }
  pools.sort((a, b) => a.name.localeCompare(b.name) || a.node.localeCompare(b.node));

  // zfspool storages that are configured but NOT available = a pool that has dropped
  // out (or never imported). This is the donatello/leonardo signal.
  const down = storageRes
    .filter(s => s.plugintype === 'zfspool' && s.status !== 'available')
    .map(s => ({ name: s.storage, node: s.node, state: s.status || 'unavailable', status: 'crit' }))
    .sort((a, b) => a.name.localeCompare(b.name) || a.node.localeCompare(b.node));

  // Per-guest rootfs fill. LXC report disk/maxdisk; QEMU usually report disk=0
  // (no agent) so they're skipped rather than shown as 0%.
  const guests = vmRes
    .filter(v => v.type === 'lxc' && v.maxdisk > 0 && v.disk > 0)
    .map(v => {
      const p = pct(v.disk, v.maxdisk);
      return { vmid: v.vmid, name: v.name, node: v.node, used: v.disk, total: v.maxdisk, pct: p, status: sev(p) };
    })
    .sort((a, b) => b.pct - a.pct);

  const alerts = [
    ...down.map(d => `${d.name} (${d.node}) ${d.state}`),
    ...pools.filter(p => p.health !== 'ONLINE').map(p => `pool ${p.name} ${p.health}`),
    ...guests.filter(g => g.status !== 'ok').map(g => `CT ${g.vmid} ${g.name} ${g.pct}%`)
  ];

  return { worst: worstOf([...pools, ...down, ...guests]), pools, down, guests, alerts };
}

export async function storageHealth(opts = {}) {
  const cfg = {
    apiUrl: opts.apiUrl || process.env.PROXMOX_API_URL,
    token: opts.token || process.env.PROXMOX_RO_TOKEN || process.env.PROXMOX_API_TOKEN,
    fetchImpl: opts.fetchImpl || fetch
  };
  if (!cfg.apiUrl || !cfg.token) return { error: 'proxmox_not_configured', at: Date.now() };
  try {
    const [storageRes, vmRes, nodes] = await Promise.all([
      pveGet('/cluster/resources?type=storage', cfg),
      pveGet('/cluster/resources?type=vm', cfg),
      pveGet('/nodes', cfg)
    ]);
    const zfsByNode = {};
    await Promise.all((nodes || [])
      .filter(n => n.status === 'online')
      .map(async n => { zfsByNode[n.node] = await pveGet(`/nodes/${n.node}/disks/zfs`, cfg).catch(() => []); }));
    return { ...normalizeStorage(storageRes, vmRes, zfsByNode), at: Date.now() };
  } catch (e) {
    return { error: String(e.message || e), at: Date.now() };
  }
}