Connecting to External Databases

module.exports = ({ get, set, update, addCallable, startDB, addDomain, ... }) => {

  // Import the server SDK for external connections
  const path = require('path');
  const createServerClient = require('../sys/serversdk.js');

  // Connect to an external NukeBase database
  // Note: External connections ARE async (like client-side)
  // The second argument is REQUIRED: a JSON file holding { uid, token } for the
  // session to connect as. Use a build token (dashboard → Signed-in devices →
  // Create build token) for the account that owns the other project; keep the
  // file out of public/. The SDK sends them as cookies.
  createServerClient('wss://other-project.nukebase.com',
                     path.join(__dirname, 'external-session.json')).then(externalDb => {
    console.log('Connected to external database');

    // Use the external database with async operations
    addCallable("getExternalData", async function(data, admin, sessionId) {
      // Local database (sync)
      const localUser = get(["users", admin.uid]);

      // External database (async - requires await)
      const externalData = await externalDb.get(["sharedData", data.itemId]);

      return {
        local: localUser.data,
        external: externalData.data
      };
    });

    // Subscribe to changes on external database
    externalDb.getSub({
      event: "value@",
      path: ["notifications"]
    }, (event) => {
      // When external data changes, update local database
      set(["cache", "externalNotifications"], event.data);
    });

  }).catch(err => {
    console.error('Failed to connect to external database:', err);
  });

  // Set up local domain
  const nukebase = addDomain({
    authPath: ["users"]
  });

  startDB(nukebase);
};