Camamba Hook Into OnMessage

allows to add handlers for onMessage requests
当前为 2021-03-22 提交的版本，查看最新版本。
此脚本不应直接安装。它是供其他脚本使用的外部库，要使用该库请加入元指令 // @require https://update.greasyfork.icu/scripts/423665/913862/Camamba%20Hook%20Into%20OnMessage.js
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换行
// ==UserScript==
// @name            Camamba Hook Into OnMessage
// @namespace       dannysaurus.camamba
// @version         0.1
// @description     allows to add handlers for onMessage requests
// @license         MIT License
// @include         https://www.camamba.com/chat/
// @include         https://www.de.camamba.com/chat/
// ==/UserScript==

/* jslint esnext: true */
/* global me, camData, rooms, blockList, friendList, friendRequests, adminMessages, jsLang, byId, myRooms, knownUsers, activeRoom, selectedUser, settings */

// === overwrite relevant property to add handler before onMessage is going to be processed
const onMessageHandlers = {
    // Keepalive response
    pong: null,
    // Chat message
    roomChat: null,
    // Private message
    'private': null,
    // Control messages
    control: null,
    // User Joined Room
    joined: null,
    // User left
    left: null,
    // User disconnected from server
    disco: null,
    // Room User List
    roomList: null,
    // Room access denied
    denied: null,
    // Private room ready
    privateCreate: null,
    // Owner of a private room left the chat
    ownerLeft: null,
    // User joins my room
    joinRequest: null,
    // Room user count
    roomStats: null,
    // Private room data
    privStats:  null,
    // Image Upload
    file: null,
    // Cam published
    camOn: null,
    // Cam turned off
    camOff: null,
    // AFK mark
    afk: null,
    // Second login overrides
    duplicate: null,
    // Admin messages
    admin: null,
    // Admin ban
    ban: null,
    // Connected (control layer)
    connectConfirm: null,
};

// === overwrite relevant property to add handler after onMessage got processed
const postMessageHandlers = {
    // Keepalive response
    pong: null,
    // Chat message
    roomChat: null,
    // Private message
    'private': null,
    // Control messages
    control: null,
    // User Joined Room
    joined: null,
    // User left
    left: null,
    // User disconnected from server
    disco: null,
    // Room User List
    roomList: null,
    // Room access denied
    denied: null,
    // Private room ready
    privateCreate: null,
    // Owner of a private room left the chat
    ownerLeft: null,
    // User joins my room
    joinRequest: null,
    // Room user count
    roomStats: null,
    // Private room data
    privStats:  null,
    // Image Upload
    file: null,
    // Cam published
    camOn: null,
    // Cam turned off
    camOff: null,
    // AFK mark
    afk: null,
    // Second login overrides
    duplicate: null,
    // Admin messages
    admin: null,
    // Admin ban
    ban: null,
    // Connected (control layer)
    connectConfirm: null,
};

// perform hook
const hookIntoOnMessage = function({
    onMessage = (m => true),
    postMessage = (m => {}),
    timeOutRetryMillis = 350
} = {}) {
    /* eslint-disable no-undef */
    if (!ws || !ws.onmessage) {
        // retry
        setTimeout(() => {
            hookIntoOnMessage({ onMessage, postMessage, timeOutRetryMillis });
        }, timeOutRetryMillis);

        return;
    }

    // perform hook
    const originalOnMessage = ws.onmessage;

    ws.onmessage = (message) => {
        const resultOnMessage = onMessage(message);

        if (resultOnMessage) {
            originalOnMessage(message);
            postMessage(message);
        }
    };
    /* eslint-enable no-undef */
};

hookIntoOnMessage({
    onMessage: (message) => {
        const data = JSON.parse(message.data);

        const handler = onMessageHandlers[data.command];
        if (typeof handler === 'function') {
            const result = handler(data);
            
            message.data = JSON.stringify(data);
            return result;
        }
        
        return true;
    },
    postMessage: (message) => {
        const data = JSON.parse(message.data);

        let handler = postMessageHandlers[data.command];
        if (typeof handler === 'function') {
            handler(data);
        }
    }
});