import { onMounted, ref } from "vue";
import { APP_NAME, APP_VERSION } from "../version";

export interface SacVersionInfo {
  name: string;
  version: string;
}

let cached: SacVersionInfo | null = null;
let inflight: Promise<SacVersionInfo> | null = null;

async function fetchSacVersion(): Promise<SacVersionInfo> {
  if (cached) {
    return cached;
  }
  if (inflight) {
    return inflight;
  }

  inflight = (async () => {
    const fallback: SacVersionInfo = { name: APP_NAME, version: APP_VERSION };
    try {
      const response = await fetch("/health");
      if (!response.ok) {
        return fallback;
      }
      const data = (await response.json()) as { name?: string; version?: string };
      const info: SacVersionInfo = {
        name: (data.name || APP_NAME).trim() || APP_NAME,
        version: (data.version || APP_VERSION).trim() || APP_VERSION,
      };
      cached = info;
      return info;
    } catch {
      return fallback;
    } finally {
      inflight = null;
    }
  })();

  return inflight;
}

/** Версия SAC с бэкенда (/health); fallback — frontend/src/version.ts */
export function useSacVersion() {
  const appName = ref(APP_NAME);
  const appVersion = ref(APP_VERSION);

  onMounted(() => {
    void fetchSacVersion().then((info) => {
      appName.value = info.name;
      appVersion.value = info.version;
    });
  });

  return { appName, appVersion };
}