// ==UserScript==
// @name         avecrypto
// @namespace    http://tampermonkey.net/
// @version      1
// @description  try to take over the world!
// @author       anonymousse
// @match        https://avenoel.org/*
// @exclude      https://avenoel.org/chat*
// @exclude      https://avenoel.org/admin*
// @grant        none
// ==/UserScript==

const CURRENT_VERSION = 1;
const START_DELIMITER = '#secret#start#';
const END_DELIMITER = '#secret#end#';
const SUBSTITUTORS = [
    ['=', '##EQUAL##'],
    ['+', '##PLUS##'],
    ['/', '##SLASH##'],
];

const CRYPTO_REGEXP = new RegExp(`#v([0-9]+)${START_DELIMITER}([a-zA-Z0-9#]+)${END_DELIMITER}`);

function getSelection (field) {
    return field.value.substring(field.selectionStart, field.selectionEnd);
}

function replaceSelection (field, new_value) {
    field.value = [field.value.slice(0, field.selectionStart), new_value, field.value.slice(field.selectionEnd)].join('');
}

function encode (text) {
    return SUBSTITUTORS.reduce((acc, v) => acc.split(v[0]).join(v[1]), btoa(text));
}

function decode (text) {
    return atob(SUBSTITUTORS.reduce((acc, v) => acc.split(v[1]).join(v[0]), text));
}

function formatForHide (text) {
    return `<color=#v${CURRENT_VERSION}${START_DELIMITER}${encode(text)}${END_DELIMITER}> </color>`;
}

function formatForDisp (text, version) {
    return `Message Avepremium: <spoiler>${decode(text)}</spoiler>`;
}

function createButton () {
    const button = $('<button type="button" class="btn" tabindex="-1" href="#">');
    const img = $('<img src="https://avenoel.org/images/smilies/724771109.gif">');

    img.appendTo(button);

    button.click(function () {
        let field = $(this).closest('form').find('textarea')[0];

        if (field.selectionStart === field.selectionEnd) {
            return console.log('vous devez selectionner le texte à cacher');
        }
        let text = getSelection(field);
        replaceSelection(field, formatForHide(text));
    });

    return button;
}

(function() {
    'use strict';

    createButton().appendTo($('.bbcodes'));

    if (document.location.pathname.split('/')[1] === 'topic') {
        $('.text-color').filter(function () {
            return CRYPTO_REGEXP.test($(this).attr('style'));
        }).each(function () {
            let [,version, text] = $(this).attr('style').match(CRYPTO_REGEXP);
            $.post('https://avenoel.org/previsualisation', {content: formatForDisp(text, version)}).done(res => {
                $(this).html(res.content);
            });
        });
    }
})();