firebase-database.js

/**
 * Copyright 2016 Google Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// Client and Server Data Fetching Logic
// Uses either the client firebase (initialized from hosting init script)
// Or serverside firebase
const firebase = global.firebase || require('firebase');

// Initialize Firebase SDK
// Only should be called once on the server
// the client should already be initialized from hosting init script
const initializeApp = config => {
  if (firebase.apps.length === 0) {
    firebase.initializeApp(config);
  }
};

// Get and return all employees
const getAllEmployees = () => {
  return firebase.database().ref('/employees').orderByChild('level').once('value').then(snap => {
    return {employees: snap.val()};
  });
};

// Get and return an employee by their id number
// also fetch all of the employee's direct reports (if any)
const getEmployeeById = employeeId => {
  return firebase.database().ref(`/employees/${employeeId}`).once('value').then(snap => {
    const promises = [];
    const snapshot = snap.val();
    if (snapshot.reports) {
      Object.keys(snapshot.reports).forEach(userId => {
        promises.push(firebase.database().ref(`/employees/${userId}`).once('value').then(snap => snap.val()));
      });
    }
    return firebase.Promise.all(promises).then((resp) => {
      return {currentEmployee: {employee: snapshot, reports: resp}};
    });
  });
};

module.exports = {
  getAllEmployees,
  getEmployeeById,
  initializeApp
};