import { AppMetaDb } from './database';
import { getConfiguredBackendRootUrl } from '../utils/backendUrl';
import { getAppInfoHeaders } from '../utils/appInfoHeaders';

const INSTALL_ID_KEY = 'install_ping_id_v1';
const INSTALL_REPORTED_KEY = 'install_ping_reported_v1';
const REQUEST_TIMEOUT_MS = 10000;

const getOrCreateInstallId = (): string => {
  const existing = AppMetaDb.get(INSTALL_ID_KEY);
  if (existing) return existing;
  const installId = `${Date.now().toString(36)}-${Math.random().toString(36).slice(2, 12)}-${Math.random().toString(36).slice(2, 12)}`;
  AppMetaDb.set(INSTALL_ID_KEY, installId);
  return installId;
};

// Reports this install to the backend exactly once (fire-and-forget). The
// backend dedupes by install id, so retrying after a failed attempt is safe.
export const reportInstallOnce = async (): Promise<void> => {
  try {
    if (AppMetaDb.get(INSTALL_REPORTED_KEY) === '1') return;
    const backendBaseUrl = getConfiguredBackendRootUrl();
    if (!backendBaseUrl) return;

    const controller = new AbortController();
    const timeout = setTimeout(() => controller.abort(), REQUEST_TIMEOUT_MS);
    try {
      const response = await fetch(`${backendBaseUrl.replace(/\/$/, '')}/v1/app-install`, {
        method: 'POST',
        headers: {
          'Content-Type': 'application/json',
          ...getAppInfoHeaders(),
        },
        body: JSON.stringify({ installId: getOrCreateInstallId() }),
        signal: controller.signal,
      });
      if (response.ok) {
        AppMetaDb.set(INSTALL_REPORTED_KEY, '1');
      }
    } finally {
      clearTimeout(timeout);
    }
  } catch {
    // Offline or backend unreachable — retried on next app start.
  }
};