/**
 * Pure helpers for adding a printer through a gateway, with no imports so
 * they test without a database - same reasoning as `dispatch/job_status.ts`.
 */

/**
 * Vendors a gateway can drive, by the name the gateway knows them as, and
 * what each needs to be told. `prusa_link` is stored as `prusa` and
 * `octoprint` as itself - the database enum predates the gateway's names.
 *
 * Bambu is verified against real printers. The other three are written from
 * their public APIs and tested against mock servers only.
 */
export const PROVISIONABLE_VENDORS = ["bambu", "klipper", "octoprint", "prusa_link"] as const;
export type ProvisionableVendor = (typeof PROVISIONABLE_VENDORS)[number];

const NEEDS: Record<ProvisionableVendor, { accessCode?: true; serialNumber?: true; apiKey?: true; dbVendor: "bambu" | "klipper" | "octoprint" | "prusa" }> = {
  bambu: { accessCode: true, serialNumber: true, dbVendor: "bambu" },
  klipper: { dbVendor: "klipper" },
  octoprint: { apiKey: true, dbVendor: "octoprint" },
  prusa_link: { apiKey: true, dbVendor: "prusa" },
};

export const dbVendorFor = (vendor: ProvisionableVendor) => NEEDS[vendor].dbVendor;

/** The first credential this vendor needs that was not supplied, named for the operator. */
export function missingCredential(
  vendor: ProvisionableVendor,
  given: { accessCode?: string; serialNumber?: string; apiKey?: string },
): string | undefined {
  const needs = NEEDS[vendor];
  if (needs.accessCode && !given.accessCode?.trim()) return "an access code";
  if (needs.serialNumber && !given.serialNumber?.trim()) return "a serial number";
  if (needs.apiKey && !given.apiKey?.trim()) return "an API key";
  return undefined;
}

/**
 * The id the gateway will know this printer by, chosen here so telemetry
 * arrives under an id the cloud already holds. A readable slug of the name
 * plus a random suffix: readable because it shows up in the gateway's logs
 * and certificate-pin file names, random because two printers may share a
 * name. Constrained to what the gateway accepts (`^[A-Za-z0-9_-]{1,64}$`).
 */
export function gatewayIdFor(name: string, random: () => number = Math.random): string {
  const slug =
    name
      .toLowerCase()
      .replace(/[^a-z0-9]+/g, "-")
      .replace(/^-+|-+$/g, "")
      .slice(0, 40) || "printer";
  const suffix = Math.floor(random() * 0xffff)
    .toString(16)
    .padStart(4, "0");
  return `${slug}-${suffix}`;
}

/**
 * What to tell the operator when the gateway says no, without ever repeating
 * the credential back. The gateway's messages do not contain it by design,
 * and this is the second line of that defence: anything that does is dropped.
 */
export function safeGatewayError(error: string | undefined, secrets: string[]): string {
  let message = error ?? "the gateway did not say why";
  for (const secret of secrets) {
    if (secret) message = message.split(secret).join("<hidden>");
  }
  return message;
}