/**
 * Proxmox VE adapter — uses the Proxmox VE REST API (api2/json).
 * Requires config: url, tokenId, tokenSecret; optional: insecure
 *
 * Auth: `Authorization: PVEAPIToken=<tokenId>=<tokenSecret>` — see
 * https://pve.proxmox.com/wiki/Proxmox_VE_API#API_Tokens
 *
 * Endpoints verified against Proxmox's own published API tree
 * (https://pve.proxmox.com/pve-docs/api-viewer/apidoc.js): GET /nodes, GET
 * /nodes/{node}/qemu, GET /nodes/{node}/lxc, and POST
 * /nodes/{node}/{qemu,lxc}/{vmid}/status/{start,stop,reboot} (all
 * token-auth-eligible per that spec's "allowtoken" flag).
 *
 * Proxmox commonly runs with a self-signed certificate in homelab setups, so
 * (like the cPanel DNS adapter) this uses node:https directly rather than
 * fetch, to support an "insecure" opt-out of certificate verification.
 */
import * as https from "node:https";
import { withDiagLogging } from "../../services/diagLog.js";

export interface ProxmoxConfig {
  url: string;
  tokenId: string;
  tokenSecret: string;
  insecure?: boolean;
}

export type ProxmoxGuestType = "qemu" | "lxc";

export interface ProxmoxGuest {
  vmid: number;
  name: string;
  node: string;
  type: ProxmoxGuestType;
  status: string; // "running" | "stopped"
  cpu: number | null;
  maxmem: number | null;
  mem: number | null;
  uptime: number | null;
}

export interface ProxmoxGuestDetail {
  vmid: number;
  node: string;
  type: ProxmoxGuestType;
  name: string;
  status: string;
  cpuCores: number | null;
  cpuUsagePercent: number | null;
  memoryBytes: number | null;
  memUsedBytes: number | null;
  diskBytes: number | null;
  /**
   * Per-mount usage where Proxmox can actually see it: the LXC root
   * filesystem (host can see straight into it, no agent needed) or, for a
   * QEMU VM, whatever the QEMU guest agent reports from inside the guest.
   * Empty when neither is available (e.g. no guest agent) — diskBytes above
   * (allocated size) is still shown in that case, just not usage.
   */
  disks: { mount: string; sizeBytes: number; usedBytes: number }[];
  uptime: number | null;
  ipAddresses: string[];
  /** QEMU only — false when the guest agent call failed (not installed/running). Always true for LXC (IPs/disk usage read directly, no agent needed). */
  guestAgentAvailable: boolean;
}

export interface ProxmoxStorage {
  id: string;
  type: string;
  active: boolean;
  shared: boolean;
  totalBytes: number | null;
  usedBytes: number | null;
  availBytes: number | null;
}

export interface ProxmoxNodeStats {
  node: string;
  /** Set (with every other field null/empty) when this node's status/storage couldn't be fetched — e.g. the API token lacks Sys.Audit/Datastore.Audit. */
  error: string | null;
  uptime: number | null;
  cpuUsagePercent: number | null;
  cpuCores: number | null;
  loadAverage: [number, number, number] | null;
  memTotalBytes: number | null;
  memUsedBytes: number | null;
  swapTotalBytes: number | null;
  swapUsedBytes: number | null;
  rootfsTotalBytes: number | null;
  rootfsUsedBytes: number | null;
  pveVersion: string | null;
  storages: ProxmoxStorage[];
}

export interface ProxmoxAdapter {
  ping(): Promise<{ ok: boolean; latencyMs?: number; error?: string }>;
  listGuests(): Promise<ProxmoxGuest[]>;
  getGuestDetail(node: string, type: ProxmoxGuestType, vmid: number): Promise<ProxmoxGuestDetail>;
  listNodeStats(): Promise<ProxmoxNodeStats[]>;
  startGuest(node: string, type: ProxmoxGuestType, vmid: number): Promise<void>;
  stopGuest(node: string, type: ProxmoxGuestType, vmid: number): Promise<void>;
  restartGuest(node: string, type: ProxmoxGuestType, vmid: number): Promise<void>;
  /** Graceful shutdown (ACPI power event for a VM, SIGTERM-then-wait for a container) — unlike stopGuest, this asks the guest OS to shut itself down. */
  shutdownGuest(node: string, type: ProxmoxGuestType, vmid: number): Promise<void>;
}

function parseSizeToBytes(size: string): number | null {
  const match = size.match(/^(\d+(?:\.\d+)?)\s*([KMGT])?$/i);
  if (!match) return null;
  const value = parseFloat(match[1]);
  const unit = (match[2] ?? "").toUpperCase();
  const multiplier = ({ "": 1, K: 1024, M: 1024 ** 2, G: 1024 ** 3, T: 1024 ** 4 } as Record<string, number>)[unit] ?? 1;
  return Math.round(value * multiplier);
}

function extractSizeParam(configValue: string): number | null {
  const match = configValue.match(/(?:^|,)size=([\d.]+[KMGT]?)/i);
  return match ? parseSizeToBytes(match[1]) : null;
}

function extractIpFromNetConfig(configValue: string): string | null {
  const match = configValue.match(/(?:^|,)ip=([^,]+)/i);
  if (!match) return null;
  const ip = match[1];
  if (ip.toLowerCase() === "dhcp" || ip.toLowerCase() === "manual") return null;
  return ip.split("/")[0];
}

interface RawResponse {
  status: number;
  text: () => string;
}

function request(url: string, insecure: boolean, options: { method?: string; headers?: Record<string, string> } = {}): Promise<RawResponse> {
  return new Promise((resolve, reject) => {
    const parsed = new URL(url);
    const req = https.request(
      {
        hostname: parsed.hostname,
        port: parsed.port || 8006,
        path: parsed.pathname + parsed.search,
        method: options.method || "GET",
        headers: options.headers || {},
        rejectUnauthorized: !insecure,
      },
      (res) => {
        let body = "";
        res.setEncoding("utf8");
        res.on("data", (chunk) => {
          body += chunk;
        });
        res.on("end", () => resolve({ status: res.statusCode ?? 0, text: () => body }));
      },
    );
    req.on("error", reject);
    req.end();
  });
}

export function createProxmoxAdapter(config: ProxmoxConfig): ProxmoxAdapter {
  const insecure = config.insecure === true;

  function base() {
    return config.url.replace(/\/$/, "");
  }

  function headers() {
    return {
      Authorization: `PVEAPIToken=${config.tokenId}=${config.tokenSecret}`,
      Accept: "application/json",
    };
  }

  async function api(method: string, path: string): Promise<any> {
    const res = await request(`${base()}/api2/json${path}`, insecure, { method, headers: headers() });
    let data: any = null;
    try {
      data = res.text() ? JSON.parse(res.text()) : null;
    } catch {
      // non-JSON error page
    }
    if (res.status < 200 || res.status >= 300) {
      const message = data?.errors ? JSON.stringify(data.errors) : data?.message;
      throw new Error(message || `Proxmox API error: HTTP ${res.status}`);
    }
    return data?.data;
  }

  async function listNodes(): Promise<string[]> {
    const data = await api("GET", "/nodes");
    return (Array.isArray(data) ? data : [])
      .filter((n: any) => n.status === "online")
      .map((n: any) => n.node);
  }

  async function listGuestsForNode(node: string, type: ProxmoxGuestType): Promise<ProxmoxGuest[]> {
    const data = await api("GET", `/nodes/${node}/${type}`);
    return (Array.isArray(data) ? data : []).map((g: any) => ({
      vmid: g.vmid,
      name: g.name,
      node,
      type,
      status: g.status,
      cpu: g.cpu ?? null,
      maxmem: g.maxmem ?? null,
      mem: g.mem ?? null,
      uptime: g.uptime ?? null,
    }));
  }

  async function listGuests(): Promise<ProxmoxGuest[]> {
    const nodes = await listNodes();
    const perNode = await Promise.all(
      nodes.map(async (node) => {
        try {
          const [vms, containers] = await Promise.all([
            listGuestsForNode(node, "qemu"),
            listGuestsForNode(node, "lxc"),
          ]);
          return [...vms, ...containers];
        } catch {
          // one unreachable/offline node shouldn't take down the whole dashboard view
          return [];
        }
      }),
    );
    return perNode.flat();
  }

  async function getGuestDetail(node: string, type: ProxmoxGuestType, vmid: number): Promise<ProxmoxGuestDetail> {
    const [config, status] = await Promise.all([
      api("GET", `/nodes/${node}/${type}/${vmid}/config`),
      api("GET", `/nodes/${node}/${type}/${vmid}/status/current`),
    ]);

    let cpuCores: number | null = null;
    let diskBytes: number | null = null;
    const ipAddresses: string[] = [];
    const disks: { mount: string; sizeBytes: number; usedBytes: number }[] = [];
    let guestAgentAvailable = true;

    if (type === "lxc") {
      cpuCores = typeof config.cores === "number" ? config.cores : null;
      if (typeof config.rootfs === "string") {
        diskBytes = extractSizeParam(config.rootfs);
      }
      for (const key of Object.keys(config)) {
        if (/^net\d+$/.test(key) && typeof config[key] === "string") {
          const ip = extractIpFromNetConfig(config[key]);
          if (ip) ipAddresses.push(ip);
        }
      }
      // The host can see straight into an LXC's root filesystem — no agent
      // needed — but the API only exposes the root mount this way, not any
      // additional mount points configured on the container.
      if (typeof status.disk === "number" && typeof status.maxdisk === "number" && status.maxdisk > 0) {
        disks.push({ mount: "/", sizeBytes: status.maxdisk, usedBytes: status.disk });
      }
    } else {
      const sockets = typeof config.sockets === "number" ? config.sockets : 1;
      cpuCores = typeof config.cores === "number" ? config.cores * sockets : null;

      let totalDisk = 0;
      let foundDisk = false;
      for (const key of Object.keys(config)) {
        if (/^(scsi|virtio|sata|ide)\d+$/.test(key) && typeof config[key] === "string") {
          const size = extractSizeParam(config[key]);
          if (size !== null) {
            totalDisk += size;
            foundDisk = true;
          }
        }
      }
      diskBytes = foundDisk ? totalDisk : null;

      try {
        const agentData = await api("GET", `/nodes/${node}/qemu/${vmid}/agent/network-get-interfaces`);
        const interfaces = agentData?.result ?? [];
        for (const iface of interfaces) {
          for (const addr of iface["ip-addresses"] ?? []) {
            if (addr["ip-address-type"] === "ipv4" && addr["ip-address"] !== "127.0.0.1") {
              ipAddresses.push(addr["ip-address"]);
            }
          }
        }
      } catch {
        guestAgentAvailable = false;
      }

      // Unlike LXC, the hypervisor can't see inside a QEMU disk image at
      // all — actual filesystem usage only exists if the guest agent
      // reports it from inside the guest, same availability caveat as the
      // network call above (a separate try/catch since one agent command
      // failing, e.g. on an older guest agent version, shouldn't hide IPs
      // the other command already got, or vice versa).
      try {
        const fsData = await api("GET", `/nodes/${node}/qemu/${vmid}/agent/get-fsinfo`);
        for (const fs of fsData?.result ?? []) {
          // Entries with no backing "disk" (tmpfs, proc, overlay, snap loop
          // mounts, ...) aren't real storage — skip them, same convention
          // widely used for this endpoint.
          if (!Array.isArray(fs.disk) || fs.disk.length === 0) continue;
          if (typeof fs["total-bytes"] !== "number" || typeof fs["used-bytes"] !== "number") continue;
          disks.push({ mount: fs.mountpoint ?? fs.name ?? "?", sizeBytes: fs["total-bytes"], usedBytes: fs["used-bytes"] });
        }
      } catch {
        // Guest agent unavailable or too old to support get-fsinfo — leave
        // disks empty, diskBytes (allocated size) is still shown.
      }
    }

    const memoryBytes = typeof config.memory === "number" ? config.memory * 1024 * 1024 : null;

    return {
      vmid,
      node,
      type,
      name: config.name ?? `${type}/${vmid}`,
      status: status.status,
      cpuCores,
      cpuUsagePercent: typeof status.cpu === "number" ? status.cpu * 100 : null,
      memoryBytes,
      memUsedBytes: typeof status.mem === "number" ? status.mem : null,
      diskBytes,
      disks,
      uptime: typeof status.uptime === "number" ? status.uptime : null,
      ipAddresses,
      guestAgentAvailable: type === "qemu" ? guestAgentAvailable : true,
    };
  }

  const emptyNodeStats = (node: string, error: string | null): ProxmoxNodeStats => ({
    node,
    error,
    uptime: null,
    cpuUsagePercent: null,
    cpuCores: null,
    loadAverage: null,
    memTotalBytes: null,
    memUsedBytes: null,
    swapTotalBytes: null,
    swapUsedBytes: null,
    rootfsTotalBytes: null,
    rootfsUsedBytes: null,
    pveVersion: null,
    storages: [],
  });

  function errorMessage(reason: unknown): string {
    return reason instanceof Error ? reason.message : String(reason);
  }

  async function getNodeStats(node: string): Promise<ProxmoxNodeStats> {
    // Host status and storage usage need different ACL privileges
    // (Sys.Audit vs Datastore.Audit) — a token scoped only for VM/LXC
    // management (this integration's original scope) may have one but not
    // the other, so fetch them independently rather than losing both to
    // Promise.all's fail-fast behavior.
    const [statusResult, storageResult] = await Promise.allSettled([
      api("GET", `/nodes/${node}/status`),
      api("GET", `/nodes/${node}/storage`),
    ]);

    const status = statusResult.status === "fulfilled" ? statusResult.value : null;
    const storages = storageResult.status === "fulfilled" ? storageResult.value : null;

    const errors: string[] = [];
    if (statusResult.status === "rejected") errors.push(`host stats: ${errorMessage(statusResult.reason)}`);
    if (storageResult.status === "rejected") errors.push(`storage: ${errorMessage(storageResult.reason)}`);

    const loadavgRaw = Array.isArray(status?.loadavg) ? status.loadavg.map((v: string) => Number(v)) : null;
    const loadAverage: [number, number, number] | null =
      loadavgRaw && loadavgRaw.length === 3 && loadavgRaw.every((n: number) => Number.isFinite(n))
        ? (loadavgRaw as [number, number, number])
        : null;

    return {
      node,
      error: errors.length > 0 ? errors.join("; ") : null,
      uptime: typeof status?.uptime === "number" ? status.uptime : null,
      cpuUsagePercent: typeof status?.cpu === "number" ? status.cpu * 100 : null,
      cpuCores: typeof status?.cpuinfo?.cpus === "number" ? status.cpuinfo.cpus : null,
      loadAverage,
      memTotalBytes: typeof status?.memory?.total === "number" ? status.memory.total : null,
      memUsedBytes: typeof status?.memory?.used === "number" ? status.memory.used : null,
      swapTotalBytes: typeof status?.swap?.total === "number" ? status.swap.total : null,
      swapUsedBytes: typeof status?.swap?.used === "number" ? status.swap.used : null,
      rootfsTotalBytes: typeof status?.rootfs?.total === "number" ? status.rootfs.total : null,
      rootfsUsedBytes: typeof status?.rootfs?.used === "number" ? status.rootfs.used : null,
      pveVersion: typeof status?.pveversion === "string" ? status.pveversion : null,
      storages: (Array.isArray(storages) ? storages : []).map((s: any) => ({
        id: s.storage,
        type: s.type,
        active: !!s.active,
        shared: !!s.shared,
        totalBytes: typeof s.total === "number" ? s.total : null,
        usedBytes: typeof s.used === "number" ? s.used : null,
        availBytes: typeof s.avail === "number" ? s.avail : null,
      })),
    };
  }

  async function listNodeStats(): Promise<ProxmoxNodeStats[]> {
    const nodes = await listNodes();
    return Promise.all(
      nodes.map(async (node) => {
        try {
          return await getNodeStats(node);
        } catch (err) {
          // Surface the failure on this node's card instead of silently
          // dropping it — that previously showed a misleading "no online
          // nodes" empty state even when nodes existed but stats couldn't
          // be fetched (e.g. missing ACL privileges on the API token).
          return emptyNodeStats(node, errorMessage(err));
        }
      }),
    );
  }

  async function statusAction(node: string, type: ProxmoxGuestType, vmid: number, action: string): Promise<void> {
    await api("POST", `/nodes/${node}/${type}/${vmid}/status/${action}`);
  }

  const startGuest = (node: string, type: ProxmoxGuestType, vmid: number) => statusAction(node, type, vmid, "start");
  const stopGuest = (node: string, type: ProxmoxGuestType, vmid: number) => statusAction(node, type, vmid, "stop");
  const restartGuest = (node: string, type: ProxmoxGuestType, vmid: number) => statusAction(node, type, vmid, "reboot");
  const shutdownGuest = (node: string, type: ProxmoxGuestType, vmid: number) => statusAction(node, type, vmid, "shutdown");

  async function ping(): Promise<{ ok: boolean; latencyMs?: number; error?: string }> {
    const start = Date.now();
    try {
      await api("GET", "/nodes");
      return { ok: true, latencyMs: Date.now() - start };
    } catch (err) {
      return { ok: false, error: err instanceof Error ? err.message : String(err) };
    }
  }

  return withDiagLogging("proxmox", {
    ping,
    listGuests,
    getGuestDetail,
    listNodeStats,
    startGuest,
    stopGuest,
    restartGuest,
    shutdownGuest,
  });
}