import firebase from 'firebase';

export default class BackendAPI {

  /**
   * @param {string} path
   * @param {string} method
   * @param {object} body
   * @returns {Promise}
   */
  static request(path, method = 'GET', body = null) {
    const url = `${process.env.REACT_APP_BACKEND_API}${path}`;
    const headers = { 'Accept': 'application/json' };

    if (body) {
      headers['Content-Type'] = 'application/json; charset=utf-8';
    }

    const call = () => fetch(url, {
      method,
      headers,
      body: body ? JSON.stringify(body) : undefined
    }).then(response => {
      if (response.ok) {
        return response.json();
      }

      return response.json().then(err => {
        throw err;
      })
    });

    if (firebase.auth().currentUser) {
      return firebase.auth().currentUser.getIdToken(true)
        .then(token => {
          headers['Authorization'] = token;
          return call();
        });
    }

    return call();
  }

  /**
   * @param {string} path
   * @returns {Promise}
   */
  static get(path) {
    return this.request(path);
  }

  /**
   * @param {string} path
   * @param {object} body
   * @returns {Promise}
   */
  static post(path, body = {}) {
    return this.request(path, 'POST', body)
  }

  /** USERS **/

  /**
   * Create a user
   *
   * @typedef {object} createUser
   * @typedef {string} createUser.firstName
   * @typedef {string} createUser.lastName
   * @typedef {string} createUser.phoneNumber
   * @typedef {string} createUser.email
   * @typedef {string} createUser.password
   *
   * @param {createUser}
   * @returns {Promise}
   */
  static createUser({
    firstName, lastName, phoneNumber, email, password
  }) {
    return this.post('/users', {
      firstName, lastName, phoneNumber, email, password
    });
  }

  /**
   * Get a user (own by default)
   *
   * @param {string} userId
   * @returns {Promise}
   */
  static getUser(userId = firebase.auth().currentUser.uid) {
    return this.get(`/users/${userId}`);
  }

  /**
   * Get a list of all users
   *
   * @returns {Promise}
   */
  static getAllUsers() {
    return this.get('/users');
  }

  /**
   * Toggle a user's admin role
   *
   * @param {string} userId
   * @returns {Promise}
   */
  static toggleAdmin(userId) {
    return this.post(`/users/${userId}/toggle-admin`);
  }

}