// create instances list
const instances = {};

class ODM {

  constructor(document) {
    // get class name
    const name = this.constructor.name;

    // add unique id
    if (!document._id) document._id = Math.random().toString();

    // create document
    if (!db[name]) db[name] = {};
    db[name][document._id] = document;

    // define accessors
    const configuration = {};
    Object.keys(document).forEach((prop) => {
      configuration[prop] = {
        get() {
          return db[name][document._id][prop];
        },
        set(value) {
          db[name][document._id][prop] = value;
        }
      };
    });

    // set accessors
    Object.defineProperties(this, configuration);

    // add it to the list of instances
    instances[document._id] = this;
  }
}