// ==UserScript==
// @name         crypto
// @namespace    http://tampermonkey.net/
// @version      0.1
// @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==


function createKey (str_key) {
    let raw_key = Uint8Array.from(btoa(str_key), c => c.charCodeAt(0)).buffer;
    return crypto.subtle.digest('sha-256', raw_key).then(hash_key => {
        return crypto.subtle.importKey('raw', hash_key, { name: 'AES-CBC' }, false, ['encrypt', 'decrypt']);
    });
}

function encrypt (msg, str_key) {
    let data = Uint8Array.from(btoa(msg), c => c.charCodeAt(0));

    let initVector = new Uint8Array(16);

    crypto.getRandomValues(initVector);

    return createKey(str_key).then(key => {
        return crypto.subtle.encrypt({ name: 'AES-CBC', iv: initVector}, key, data);
    }).then(encrypted => {
        encrypted = new Uint8Array(encrypted);
        return btoa(encrypted) + '.' + btoa(initVector);
    });
}

function decrypt (msg, str_key) {
    let [encrypted, initVector] = msg.split('.');

    encrypted = new Uint8Array(atob(encrypted).split(','));
    initVector = new Uint8Array(atob(initVector).split(','));


    return createKey(str_key).then(key => {
        return crypto.subtle.decrypt({name: 'AES-CBC', iv: initVector}, key, encrypted);
    }).then(decrypted => {
        decrypted = new Uint8Array(decrypted);
        let decoded = atob(String.fromCharCode.apply(null, decrypted));

        return decoded;
    });
}

function previsu (msg, balise) {
    let req = new XMLHttpRequest();
    let form = new FormData();
    form.append('content', '[DECRYPTED CONTENT]\n' + msg + '\n[END]');


    req.open('POST', 'https://avenoel.org/previsualisation', true);
    req.setRequestHeader('x-csrf-token', document.token);
    req.setRequestHeader('x-requested-with', 'XMLHttpRequest');
    req.onload = function (res) {
        balise.innerHTML = JSON.parse(res.srcElement.response).content;
    };
    req.send(form);
}

(function() {
    'use strict';

    document.token = document.querySelector('meta[name=csrf-token]').getAttribute('content');
    let bbcodes = document.getElementsByClassName('bbcodes')[0];
    let field = document.getElementsByTagName('textarea')[0];

    //on créé le bouton bbcode
    let button = document.createElement('button');
    button.setAttribute('type', 'button');
    button.setAttribute('class', 'btn');
    button.setAttribute('tabindex', '-1');
    button.setAttribute('href', '#');

    let img = document.createElement('img');
    img.setAttribute('src', 'https://avenoel.org/images/smilies/724771109.gif');

    button.appendChild(img);
    button.addEventListener('click', event => {
        let key = document.getElementsByClassName('bloc-title')[0].innerText.split(' ').pop();
        if (field.selectionStart === field.selectionEnd) {
            return ;
        }
        let msg = field.value.substr(field.selectionStart, field.selectionEnd);
        previsu(msg);
        encrypt(msg, key).then(encrypted => {
            let a = `<spoiler>[WARNING ENCRYPTED CONTENT]
${encrypted}
[END]</spoiler>`;
            field.value = field.value.slice(0, field.selectionStart) + a + field.value.slice(field.selectionEnd);
        });
    });
    bbcodes.appendChild(button);

    if (document.location.pathname.split('/')[1] === 'topic') {
        Array.from(document.getElementsByClassName('message-content')).map(msg => {
            let author = msg.parentNode.getElementsByTagName('header')[0].getElementsByTagName('a')[0].pathname.split('/').pop();
            Array.from(msg.getElementsByClassName('spoiler-content')).map(spoiler => {
                if (!spoiler) return ;
                let tab = spoiler.innerText.split('\n\n');
                console.log(tab);
                if (tab.length === 3 && tab[0] === '[WARNING ENCRYPTED CONTENT]' && tab[2] === '[END]') {
                                    console.log('message encrypté;;; key = ' + author);

                    decrypt(tab[1], author).then(decrypted => {
                        previsu(decrypted, spoiler);

                    });
                }
            });
        });
    }
})();