discourse/app/assets/javascripts/admin/addon/controllers/admin-email-preview-digest.js

import { empty, notEmpty, or } from "@ember/object/computed";
import Controller from "@ember/controller";
import EmailPreview from "admin/models/email-preview";
import { action, get } from "@ember/object";
import { popupAjaxError } from "discourse/lib/ajax-error";
import { inject as service } from "@ember/service";

export default Controller.extend({
  dialog: service(),
  username: null,
  lastSeen: null,
  emailEmpty: empty("email"),
  sendEmailDisabled: or("emailEmpty", "sendingEmail"),
  showSendEmailForm: notEmpty("model.html_content"),
  htmlEmpty: empty("model.html_content"),

  @action
  toggleShowHtml(event) {
    event?.preventDefault();
    this.toggleProperty("showHtml");
  },

  actions: {
    updateUsername(selected) {
      this.set("username", get(selected, "firstObject"));
    },

    refresh() {
      const model = this.model;

      this.set("loading", true);
      this.set("sentEmail", false);

      let username = this.username;
      if (!username) {
        username = this.currentUser.get("username");
        this.set("username", username);
      }

      EmailPreview.findDigest(username, this.lastSeen).then((email) => {
        model.setProperties(
          email.getProperties("html_content", "text_content")
        );
        this.set("loading", false);
      });
    },

    sendEmail() {
      this.set("sendingEmail", true);
      this.set("sentEmail", false);

      EmailPreview.sendDigest(this.username, this.lastSeen, this.email)
        .then((result) => {
          if (result.errors) {
            this.dialog.alert(result.errors);
          } else {
            this.set("sentEmail", true);
          }
        })
        .catch(popupAjaxError)
        .finally(() => {
          this.set("sendingEmail", false);
        });
    },
  },
});