// ==UserScript==
// @name         Duolingo Auto IME On-Off
// @namespace    mog86uk-duo-autoime
// @version      1.02
// @description  Forces IME to switch between English and Japanese automatically for each typing question.
// @author       mog86uk (aka. testmoogle)
// @match        https://www.duolingo.com/*
// @exclude      https://www.duolingo.com/discussion
// @exclude      https://www.duolingo.com/topic/*
// @exclude      https://www.duolingo.com/comment/*
// @require      http://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js
// @grant        none
// @run-at       document-idle
// @downloadURL none
// ==/UserScript==


jQuery.noConflict();
jQuery(document).ready(function($) {
    'use strict';

    var typeLang = "";
    var typeLangPrevious = "";
    var alertShown = 0;

    function Start(mutationRecords) {
        if (/^https:\/\/www\.duolingo\.com.*\/practice$/.test(window.location.href) || /^https:\/\/www\.duolingo\.com\/skill\/ja\/.+\/.+$/.test(window.location.href)) {
            if (!alertShown) {
                if (typeof $('html').css('ime-mode') === 'undefined' && typeof $('html').prop('inputMode') === 'undefined') {
                    alert("If you're using Chrome or Opera, you'll need to enable the following browser flag:\n\n#enable-experimental-web-platform-features\n\nFirefox should work fine as it is, but Chrome and Opera need to enable this flag to be able to make use of the 'inputmode' experimental html attribute. (See the userscript's page on greasyfork if you need more help with enabling this browser flag.) ^^");
                }
                alertShown = 1;
            }
            else {
                mutationRecords.forEach (function (mutation) {
                    typeLang = $('textarea[data-test="challenge-translate-input"]').attr('lang');
                    if (typeLang !== typeLangPrevious || (typeLang === 'en' && $('textarea[data-test="challenge-translate-input"]').css('ime-mode') === 'auto')) {
                        if (typeLang === 'en') {
                            $('textarea[data-test="challenge-translate-input"]').attr('inputmode', 'latin').css('ime-mode', 'disabled').blur().focus();
                        }
                        else if (typeLang === 'ja') {
                            $('textarea[data-test="challenge-translate-input"]').attr('inputmode', 'kana').css('ime-mode', 'active').blur().focus();
                        }
                        typeLangPrevious = typeLang;
                    }
                });
            }
        }
    }

    if (window.top == window.self) {
        var observerOfStuff = new MutationObserver(Start);

        observerOfStuff.observe(document.body, {
            attributes: true,
            subtree: true
        });
    }
});