// Nextcloud's client — nextcloud's own code, living in the module (novox/hq ADR 0039). Both this
// module's tools and its events entrypoint import it, and nothing outside nextcloud does.
//
// Nextcloud is administered two ways, and this client speaks both:
//   - occ, its admin CLI, is a PHP script inside the container runnable only as the web user. We
//     reach it with `docker exec`, the same side channel an operator would use by hand — turned
//     into something the mesh can call. Users and apps come from here.
//   - the OCS Sharing API answers over HTTP with the admin credentials. Shares come from here,
//     because occ has no version-stable "list every share" across the releases we run.

import { execFileSync } from "node:child_process";
import { readFileSync } from "node:fs";

export interface NextcloudUser {
  uid: string;
  displayName: string;
}

export interface NextcloudShare {
  /** The OCS share id — the stable identity a new share is diffed on. */
  id: string;
  path: string;
  shareType: number;
  shareWith?: string;
  owner: string;
}

/** The settings-merged config the mesh delivers (novox/hq ADR 0046): { url, apiKey, token, password, user, ... }. */
function meshConfig(file?: string): Record<string, string> {
  if (!file) return {};
  try { return JSON.parse(readFileSync(file, "utf8")) as Record<string, string>; }
  catch { return {}; }
}

export class NextcloudClient {
  constructor(
    private readonly container: string,
    private readonly ocsUrl: string,
    private readonly adminUser: string,
    private readonly adminPassword: string,
  ) {}

  /**
   * Build from the module's resolved environment. occ needs only the container name (default
   * "nextcloud"); the OCS surface needs the admin password the module keeps as its own secret
   * (MESH_NEXTCLOUD_ADMIN_PASSWORD, user MESH_NEXTCLOUD_ADMIN_USER default admin, URL the local
   * container). The admin password is treated as the "configured for mesh administration" signal:
   * throws without it, and the module then contributes nothing rather than failing.
   */
  static fromEnv(env: NodeJS.ProcessEnv = process.env): NextcloudClient {
    const cfg = meshConfig(env.MESH_NEXTCLOUD_CONFIG_FILE);
    const container = cfg.container ?? env.MESH_NEXTCLOUD_CONTAINER ?? "nextcloud";
    const ocsUrl = cfg.url ?? env.MESH_NEXTCLOUD_URL ?? `http://127.0.0.1:${env.NEXTCLOUD_PORT ?? "80"}`;
    const adminUser = cfg.user ?? env.MESH_NEXTCLOUD_ADMIN_USER ?? "admin";
    const passwordFile = env.MESH_NEXTCLOUD_ADMIN_PASSWORD_FILE;
    const adminPassword = cfg.password ?? env.MESH_NEXTCLOUD_ADMIN_PASSWORD
      ?? (passwordFile ? readFileSync(passwordFile, "utf8").trim() : undefined);
    if (!adminPassword) {
      throw new Error("no Nextcloud admin password — set MESH_NEXTCLOUD_ADMIN_PASSWORD_FILE " +
        "(or MESH_NEXTCLOUD_ADMIN_PASSWORD)");
    }
    return new NextcloudClient(container, ocsUrl.replace(/\/$/, ""), adminUser, adminPassword);
  }

  /** Run occ inside the container as the web user, returning its stdout, throwing its own message. */
  occ(args: string[]): string {
    try {
      return execFileSync("docker", ["exec", "-u", "www-data", this.container, "php", "occ", ...args], {
        encoding: "utf8", timeout: 60_000,
      }).trim();
    } catch (err: any) {
      const detail = String(err?.stderr ?? err?.stdout ?? err?.message ?? "").trim();
      throw new Error(detail || `occ produced no output — is the ${this.container} container running?`);
    }
  }

  listUsers(): NextcloudUser[] {
    // user:list --output=json answers an object of uid → display name.
    const raw = this.occ(["user:list", "--output=json"]);
    const map = JSON.parse(raw || "{}") as Record<string, string>;
    return Object.entries(map).map(([uid, displayName]) => ({ uid, displayName }));
  }

  listApps(): { enabled: string[]; disabled: string[] } {
    const raw = this.occ(["app:list", "--output=json"]);
    const parsed = JSON.parse(raw || "{}") as { enabled?: Record<string, unknown>; disabled?: Record<string, unknown> };
    return { enabled: Object.keys(parsed.enabled ?? {}), disabled: Object.keys(parsed.disabled ?? {}) };
  }

  /** List every share, over the OCS Sharing API with the admin credentials. */
  async listShares(): Promise<NextcloudShare[]> {
    const auth = Buffer.from(`${this.adminUser}:${this.adminPassword}`).toString("base64");
    const res = await fetch(
      `${this.ocsUrl}/ocs/v2.php/apps/files_sharing/api/v1/shares?format=json`,
      { headers: { Authorization: `Basic ${auth}`, "OCS-APIRequest": "true", Accept: "application/json" } },
    );
    if (!res.ok) throw new Error(`Nextcloud OCS shares: ${res.status} ${await res.text()}`);
    const rows = ((await res.json())?.ocs?.data ?? []) as any[];
    return rows.map((s) => ({
      id: String(s.id),
      path: s.path ?? "",
      shareType: Number(s.share_type ?? -1),
      shareWith: s.share_with || undefined,
      owner: s.uid_owner ?? "unknown",
    }));
  }
}