/* Any copyright is dedicated to the Public Domain.
   http://creativecommons.org/publicdomain/zero/1.0/ */

"use strict";

/**
 * Test the debounce behavior.
 */
add_task(async function test_about_translations_debounce() {
  await openAboutTranslations({
    languagePairs: [
      { fromLang: "en", toLang: "fr" },
      { fromLang: "fr", toLang: "en" },
    ],
    runInPage: async ({ selectors }) => {
      const { document, window } = content;
      // Do not allow the debounce to come to completion.
      Cu.waiveXrays(window).DEBOUNCE_DELAY = 5;

      await ContentTaskUtils.waitForCondition(
        () => {
          return document.body.hasAttribute("ready");
        },
        "Waiting for the document to be ready.",
        100,
        200
      );

      /** @type {HTMLSelectElement} */
      const fromSelect = document.querySelector(selectors.fromLanguageSelect);
      /** @type {HTMLSelectElement} */
      const toSelect = document.querySelector(selectors.toLanguageSelect);
      /** @type {HTMLTextAreaElement} */
      const translationTextarea = document.querySelector(
        selectors.translationTextarea
      );
      /** @type {HTMLDivElement} */
      const translationResult = document.querySelector(
        selectors.translationResult
      );

      async function assertTranslationResult(translation) {
        try {
          await ContentTaskUtils.waitForCondition(
            () => translation === translationResult.innerText,
            `Waiting for: "${translation}"`,
            100,
            200
          );
        } catch (error) {
          // The result wasn't found, but the assertion below will report the error.
          console.error(error);
        }

        is(
          translation,
          translationResult.innerText,
          "The text runs through the mocked translations engine."
        );
      }

      function setInput(element, value) {
        element.value = value;
        element.dispatchEvent(new Event("input"));
      }
      setInput(fromSelect, "en");
      setInput(toSelect, "fr");
      setInput(translationTextarea, "T");

      info("Get the translations into a stable translationed state");
      await assertTranslationResult("T [en to fr]");

      info("Reset and pause the debounce state.");
      Cu.waiveXrays(window).DEBOUNCE_DELAY = 1_000_000_000;
      Cu.waiveXrays(window).DEBOUNCE_RUN_COUNT = 0;

      info("Input text which will be debounced.");
      setInput(translationTextarea, "T");
      setInput(translationTextarea, "Te");
      setInput(translationTextarea, "Tex");
      is(Cu.waiveXrays(window).DEBOUNCE_RUN_COUNT, 0, "Debounce has not run.");

      info("Allow the debounce to actually come to completion.");
      Cu.waiveXrays(window).DEBOUNCE_DELAY = 5;
      setInput(translationTextarea, "Text");

      await assertTranslationResult("TEXT [en to fr]");
      is(Cu.waiveXrays(window).DEBOUNCE_RUN_COUNT, 1, "Debounce ran once.");
    },
  });
});