import type { ComputerMode, ComputerStatus as ContractComputerStatus } from "@rakazo/contracts";

export const COMPUTER_HEARTBEAT_MS = 60_000;
export const SCREEN_URL_OPEN_ATTEMPTS = 5;
export const SCREEN_URL_RETRY_DELAY_MS = 400;

export type ComputerStatus = ContractComputerStatus;

function isLocalHostname(hostname: string) {
  return (
    hostname === "127.0.0.1" ||
    hostname === "localhost" ||
    hostname === "[::1]" ||
    hostname === "::1"
  );
}

export async function readScreenUrl(
  request: () => Promise<{ url: string | null }>,
  options: {
    attempts?: number;
    delayMs?: number;
    sleep?: (ms: number) => Promise<void>;
  } = {},
): Promise<string | null> {
  const attempts = Math.max(1, options.attempts ?? 1);
  const delayMs = options.delayMs ?? SCREEN_URL_RETRY_DELAY_MS;
  const sleep =
    options.sleep ?? ((ms: number) => new Promise((resolve) => setTimeout(resolve, ms)));
  let lastError: unknown;
  for (let attempt = 1; attempt <= attempts; attempt += 1) {
    try {
      const screen = await request();
      if (screen.url) return screen.url;
      lastError = undefined;
    } catch (error) {
      lastError = error;
    }
    if (attempt < attempts) await sleep(delayMs);
  }
  if (lastError) throw lastError;
  return null;
}

/** Point a loopback noVNC URL at the same host the app uses for the API. */
export function embeddableScreenUrl(url: string | null, apiBase: string): string | null {
  if (!url) return null;
  try {
    const parsed = new URL(url);
    const api = new URL(apiBase);
    if (isLocalHostname(parsed.hostname) && !isLocalHostname(api.hostname)) {
      parsed.hostname = api.hostname;
    }
    return parsed.toString();
  } catch {
    return url;
  }
}

export function previewPlaceholder(
  state: string | undefined,
  booting: boolean,
  name: string,
  mode?: ComputerMode,
): string {
  if (state === "booting" || booting) return "Booting live desktop…";
  if (state === "running") return computerLabel(mode, name);
  if (state === "suspended") return "Computer is asleep — take control to wake it";
  if (state === "error") return "Computer failed to boot";
  return "Computer is stopped";
}

export function controlLabel(computer: ComputerStatus | null, name: string, botId?: string) {
  if (computer?.busyBotName) return `${computer.busyBotName} is using it`;
  if (computer?.controlHolder === "user" && computer.controlBotId === botId) {
    return "You have control";
  }
  if (computer?.state === "suspended") return "Asleep";
  return computerLabel(computer?.mode, name);
}

export function computerLabel(mode: ComputerMode | undefined, name: string) {
  return mode === "dedicated" ? `${name}’s computer` : "Team Computer";
}