nHentai Helper

Download nHentai doujin as compression file easily, and add some useful features. Also support NyaHentai.

// ==UserScript==
// @name         nHentai Helper
// @name:zh-CN   nHentai 助手
// @name:zh-TW   nHentai 助手
// @namespace    https://github.com/Tsuk1ko
// @version      2.13.3
// @icon         https://nhentai.net/favicon.ico
// @description        Download nHentai doujin as compression file easily, and add some useful features. Also support NyaHentai.
// @description:zh-CN  为 nHentai 增加压缩打包下载方式以及一些辅助功能,同时支持 NyaHentai
// @description:zh-TW  爲 nHentai 增加壓縮打包下載方式以及一些輔助功能,同時支持 NyaHentai
// @author       Jindai Kirin
// @match        https://nhentai.net/*
// @include      /^https:\/\/([^\/]*\.)?(nya|dog|cat|bug|qq|fox|ee|yy)hentai[0-9]*\./
// @connect      nhentai.net
// @connect      i.nhentai.net
// @connect      json2jsonp.com
// @connect      i0.mspcdn9.xyz
// @license      GPL-3.0
// @grant        GM_addStyle
// @grant        GM_getValue
// @grant        GM_setValue
// @grant        GM_deleteValue
// @grant        GM_registerMenuCommand
// @grant        GM_xmlhttpRequest
// @grant        GM_getResourceText
// @resource     notycss https://cdn.jsdelivr.net/npm/noty@3.1.4/lib/noty.min.css
// @require      https://cdn.jsdelivr.net/npm/jquery@v3.4.1/dist/jquery.min.js
// @require      https://cdn.jsdelivr.net/npm/file-saver@2.0.2/dist/FileSaver.min.js
// @require      https://cdn.jsdelivr.net/npm/jquery-pjax@2.0.1/jquery.pjax.min.js
// @require      https://cdn.jsdelivr.net/npm/vue@2.6.11/dist/vue.min.js
// @require      https://cdn.jsdelivr.net/npm/noty@3.1.4/lib/noty.min.js
// @require      https://cdn.jsdelivr.net/npm/md5@2.3.0/dist/md5.min.js
// @require      https://cdn.jsdelivr.net/npm/comlink@4.3.0/dist/umd/comlink.min.js
// @require      https://cdn.jsdelivr.net/npm/localforage@1.10.0/dist/localforage.min.js
// @run-at       document-end
// @noframes
// @homepageURL  https://github.com/Tsuk1ko/nhentai-helper
// @supportURL   https://github.com/Tsuk1ko/nhentai-helper/issues
// ==/UserScript==

(async () => {
    'use strict';

    // 防 nhentai console 屏蔽
    if (localStorage.getItem('NHENTAI_HELPER_DEBUG') && typeof unsafeWindow.App !== 'undefined') {
        const isNodeOrElement = typeof Node === 'object' && typeof HTMLElement === 'object' ? o => o instanceof Node || o instanceof HTMLElement : o => o && typeof o === 'object' && typeof o.nodeType === 'number' && typeof o.nodeName === 'string';
        const c = unsafeWindow.console;
        c._clear = c.clear;
        c.clear = () => {};
        c._log = c.log;
        c.log = function () {
            const args = Array.from(arguments).filter(value => !isNodeOrElement(value));
            if (args.length) return c._log(...args);
        };
        unsafeWindow.Date = Date;
    }

    Array.prototype.remove = function (index) {
        if (index > -1) return this.splice(index, 1)[0];
    };

    const WORKER_THREAD_NUM = ((navigator && navigator.hardwareConcurrency) || 2) - 1;

    const _log = (...args) => console.log('[nhentai-helper]', ...args);
    const _warn = (...args) => console.warn('[nhentai-helper]', ...args);
    const _error = (...args) => console.error('[nhentai-helper]', ...args);

    class JSZipWorkerPool {
        constructor() {
            this.pool = [];
            this.WORKER_URL = URL.createObjectURL(new Blob(['importScripts("https://cdn.jsdelivr.net/npm/comlink@4.3.0/dist/umd/comlink.min.js","https://cdn.jsdelivr.net/npm/jszip@3.5.0/dist/jszip.min.js");class JSZipWorker{constructor(){this.zip=new JSZip}file(name,{data:data}){this.zip.file(name,data)}generateAsync(options,onUpdate){return this.zip.generateAsync(options,onUpdate).then(data=>Comlink.transfer({data:data},[data]))}}Comlink.expose(JSZipWorker);'], { type: 'text/javascript' }));
            for (let id = 0; id < WORKER_THREAD_NUM; id++) {
                this.pool.push({
                    id,
                    JSZip: null,
                    idle: true,
                });
            }
        }
        createWorker() {
            const worker = new Worker(this.WORKER_URL);
            return Comlink.wrap(worker);
        }
        async generateAsync(files, options, onUpdate) {
            const worker = this.pool.find(({ idle }) => idle);
            if (!worker) throw new Error('No avaliable JSZip worker.');
            worker.idle = false;
            if (!worker.JSZip) worker.JSZip = this.createWorker();
            const zip = await new worker.JSZip();
            for (const { name, data } of files) {
                await zip.file(name, Comlink.transfer({ data }, [data]));
            }
            return zip
                .generateAsync(
                    options,
                    Comlink.proxy(data => onUpdate({ workerId: worker.id, ...data }))
                )
                .then(({ data }) => {
                    worker.idle = true;
                    return data;
                });
        }
    }

    const jsZipPool = new JSZipWorkerPool();

    class JSZip {
        constructor() {
            this.files = [];
        }
        file(name, data) {
            this.files.push({ name, data });
        }
        generateAsync(options, onUpdate) {
            return jsZipPool.generateAsync(this.files, options, onUpdate);
        }
    }

    // 下载线程数
    let THREAD = GM_getValue('thread_num', 8);
    GM_registerMenuCommand('Download Thread', () => {
        let num;
        do {
            num = prompt('Please input the number of threads you want (1~32):', THREAD);
            if (num === null) return;
            num = Number(num);
        } while (isNaN(num) || num < 1 || num > 32);
        THREAD = num;
        GM_setValue('thread_num', num);
    });

    // 在新窗口打开本子
    let OPEN_ON_NEW_TAB = GM_getValue('open_on_new_tab', true);
    GM_registerMenuCommand('Open On New Tab', () => {
        OPEN_ON_NEW_TAB = confirm(`Do you want to open gallery page on a new tab?
Current: ${OPEN_ON_NEW_TAB ? 'Yes' : 'No'}

Please refresh to take effect after modification.`);
        GM_setValue('open_on_new_tab', OPEN_ON_NEW_TAB);
    });

    // 自定义下载地址
    let CUSTOM_DOWNLOAD_URL = GM_getValue('custom_download_url', '');
    GM_registerMenuCommand('Custom Download URL', () => {
        const input = prompt(
            `WARNING: Please don't set it if you don't know what this does.
Set it empty will restore it to default.

Available placeholders:
{{mid}} - Media ID
{{index}} - Page index, starting from 1
{{ext}} - Image file extension`,
            CUSTOM_DOWNLOAD_URL
        );
        if (input === null) return;
        CUSTOM_DOWNLOAD_URL = input.trim();
        GM_setValue('custom_download_url', CUSTOM_DOWNLOAD_URL);
    });

    // 自定义压缩文件名
    const CF_EXT_OLD = GM_getValue('cf_ext');
    if (CF_EXT_OLD) {
        GM_setValue('cf_name', `{{japanese}}.${CF_EXT_OLD}`);
        GM_deleteValue('cf_ext');
    }
    let CF_NAME = GM_getValue('cf_name', '{{japanese}}.zip');
    GM_registerMenuCommand('Compression Filename', () => {
        const input = prompt(
            `You can custom the naming of downloaded compression file, including the file extension.
Set it empty will restore it to default.

Available placeholders:
{{english}} - English name of doujin
{{japanese}} - Japanese name of doujin
{{pretty}} - English simple title of doujin
{{id}} - Gallery ID
{{pages}} - Number of pages`,
            CF_NAME
        );
        if (input === null) return;
        CF_NAME = input.trim() || '{{japanese}}.zip';
        GM_setValue('cf_name', CF_NAME);
    });

    // 自定义压缩级别
    let C_LEVEL = GM_getValue('c_lv', 0);
    GM_registerMenuCommand('Compression Level', () => {
        let num;
        do {
            num = prompt(
                `Please input a number (0-9) as compression level:
0: store (no compression)
1: lowest (best speed)
...
9: highest (best compression)`,
                C_LEVEL
            );
            if (num === null) return;
            num = Number(num.trim());
        } while (isNaN(num) || num < 0 || num > 9);
        C_LEVEL = num;
        GM_setValue('c_lv', C_LEVEL);
    });
    const getCompressionOptions = () => {
        if (C_LEVEL === 0) return {};
        return {
            compression: 'DEFLATE',
            compressionOptions: { level: C_LEVEL },
        };
    };

    // 文件名补零
    let FILENAME_LENGTH = GM_getValue('filename_length', 0);
    GM_registerMenuCommand('Filename Length', () => {
        let num;
        do {
            num = prompt(`Please input the minimum image filename length you want (≥0), zeros will be padded to the start of filename when its length lower than this value:`, FILENAME_LENGTH);
            if (num === null) return;
            num = Number(num);
        } while (isNaN(num) || num < 0);
        FILENAME_LENGTH = num;
        GM_setValue('filename_length', num);
    });

    GM_addStyle(GM_getResourceText('notycss'));
    GM_addStyle('.download-zip:disabled{cursor:wait}.gallery>.download-zip{position:absolute;z-index:1;left:0;top:0;opacity:.8}.gallery:hover>.download-zip{opacity:1}#download-panel::-webkit-scrollbar{width:6px;background-color:rgba(0,0,0,.7)}#download-panel::-webkit-scrollbar-thumb{background-color:rgba(255,255,255,.6)}#download-panel{overflow-x:hidden;position:fixed;top:20vh;right:0;width:calc(50vw - 620px);max-width:300px;min-width:150px;max-height:60vh;background-color:rgba(0,0,0,.7);z-index:100;font-size:12px;overflow-y:scroll}.download-item{position:relative;white-space:nowrap;padding:2px;overflow:visible}.download-item-cancel{cursor:pointer;position:absolute;top:0;right:-30px;color:#F44336;font-size:20px;line-height:30px;width:30px}.download-item.can-cancel:hover{width:calc(100% - 30px)}.download-item-title{overflow:hidden;text-overflow:ellipsis;text-align:left}.download-item-progress{background-color:rgba(0,0,255,.5);line-height:10px}.download-error .download-item-progress{background-color:rgba(255,0,0,.5)}.download-compressing .download-item-progress{background-color:rgba(0,255,0,.5)}.download-item-progress-text{transform:scale(.8)}#page-container{position:relative}#gp-view-mode-btn{position:absolute;right:0;top:0;margin:0}.btn-noty-green{background-color:#66BB6A!important}.btn-noty-blue{background-color:#42A5F5!important}.btn-noty:hover{filter:brightness(1.15)}.noty_buttons{padding-top:0!important}@media screen and (max-width:768px){#page-container{padding-top:40px}}.pages-input{-webkit-appearance:none;display:inline-block;border-radius:3px;padding:0 0.1em 0 1em;font-size:1em;width:100%;height:40px;border:0;vertical-align:top;margin-top:5px}.gallery.downloaded .caption{color:#999}');

    $('body').append('<div id="download-panel"></div>');

    const getTextFromTemplate = (template, values) => Object.keys(values).reduce((pre, key) => pre.replace(new RegExp(`{{${key}}}`, 'g'), values[key]), template);
    const getDpDlExt = () => {
        const paths = CF_NAME.split('.');
        const ext = paths[paths.length - 1];
        if (typeof ext === 'string') return ext.toUpperCase();
        return 'ZIP';
    };

    const notyOption = {
        type: 'error',
        layout: 'bottomRight',
        theme: 'nest',
        timeout: false,
        closeWith: [],
    };

    const EXT = { p: 'png', j: 'jpg', g: 'gif' };
    const getExtension = ({ t, extension }) => {
        const ext = (t && EXT[t]) || extension;
        if (!ext) throw new Error(`Unknown type "${t}"`);
        return ext;
    };

    const sleep = ms => new Promise(resolve => setTimeout(resolve, ms));

    // 页面类型
    const pageType = {
        gallery: /^\/g\/[0-9]+\/(\?.*)?$/.test(window.location.pathname),
        galleryPage: /^\/g\/[0-9]+(\/list)?\/[0-9]+\/(\?.*)?$/.test(window.location.pathname),
        list: $('.gallery').length > 0,
    };
    const isNyaHentai = window.location.host !== 'nhentai.net';

    // 队列
    class AsyncQueue {
        constructor(thread = 1) {
            this.queue = [];
            this.running = false;
            this.thread = thread;
        }
        get runningThreadNum() {
            return this.queue.filter(({ running }) => running).length;
        }
        push(fn, info) {
            this.queue.push({
                id: `${Date.now()}-${Math.random().toString(36).slice(2)}`,
                running: false,
                fn,
                info,
            });
        }
        async start() {
            if (this.thread <= 1) {
                if (this.running || this.queue.length === 0) return;
                this.running = true;
                do {
                    await this.queue[0].fn();
                    this.queue.shift();
                } while (this.queue.length > 0);
                this.running = false;
            } else {
                const running = this.runningThreadNum;
                if (running >= this.thread || this.queue.length === running) return;
                const idleItems = this.queue.filter(({ running }) => !running);
                for (let i = 0; i < Math.min(idleItems.length, this.thread - running); i++) {
                    const item = idleItems[i];
                    item.running = true;
                    item.fn().then(() => {
                        this.queue.remove(this.queue.findIndex(({ id }) => id === item.id));
                        this.start();
                    });
                }
            }
        }
        skipFromError() {
            this.queue.shift();
            return this.restartFromError();
        }
        restartFromError() {
            this.running = false;
            return this.start();
        }
    }

    // 下载队列
    const dlQueue = new AsyncQueue();
    dlQueue.skip = false;

    // 压缩队列
    const zipQueue = new AsyncQueue(WORKER_THREAD_NUM);

    // 下载历史
    const dlGidStore = await (async () => {
        const store = localforage.createInstance({
            name: 'nhentai_helper',
            storeName: 'dl_history_gid',
        });
        await store.ready();
        return store;
    })().catch(_error);
    const dlTitleStore = await (async () => {
        const store = localforage.createInstance({
            name: 'nhentai_helper',
            storeName: 'dl_history',
        });
        await store.ready();
        let historyNeedToBeMigration;
        try {
            historyNeedToBeMigration = JSON.parse(localStorage.getItem('downloadHistory'));
        } catch (e) {
            _error(e);
        }
        if (Array.isArray(historyNeedToBeMigration)) {
            localStorage.removeItem('downloadHistory');
            historyNeedToBeMigration.forEach(key => {
                if (typeof key !== 'string' || !/[0-9a-z]{32}/.test(key)) return;
                store.setItem(key, true);
            });
        }
        return store;
    })().catch(_error);
    const markAsDownloaded = (gid, title) => {
        dlGidStore && dlGidStore.setItem(String(gid), true);
        dlTitleStore && dlTitleStore.setItem(MD5(title.replace(/\s/g, '')), true).catch(_error);
    };
    const isDownloadedByGid = async gid => {
        try {
            return dlGidStore && (await dlGidStore.getItem(String(gid))) === true;
        } catch (e) {
            _error(e);
        }
        return false;
    };
    const isDownloadedByTitle = async title => {
        if (!dlTitleStore) return false;
        try {
            const md5v2 = MD5(title.replace(/\s/g, ''));
            if ((await dlTitleStore.getItem(md5v2)) === true) return true;
            const md5v1 = MD5(title);
            if ((await dlTitleStore.getItem(md5v1)) === true) {
                dlTitleStore.setItem(md5v2, true);
                dlTitleStore.removeItem(md5v1);
                return true;
            }
        } catch (e) {
            _error(e);
        }
        return false;
    };

    // 对话框
    const downloadAgainConfirm = (title, hasQueue = false) =>
        new Promise(resolve => {
            const n = new Noty({
                ...notyOption,
                text: `"${title}" is already downloaded${hasQueue ? ' or in queue' : ''}.<br>Do you want to download again?`,
                buttons: [
                    Noty.button('YES', 'btn btn-noty', () => {
                        n.close();
                        resolve(true);
                    }),
                    Noty.button('NO', 'btn btn-noty-green btn-noty', () => {
                        n.close();
                        resolve(false);
                    }),
                ],
            });
            n.show();
        });

    // 下载面板
    Vue.component('download-item', {
        props: ['item', 'index'],
        computed: {
            width() {
                const { page, done, compressing, compressingPercent } = this.item;
                return compressing ? compressingPercent.toFixed(2) : page && done ? ((100 * done) / page).toFixed(2) : 0;
            },
            canCancel() {
                return !this.item.compressing;
            },
        },
        watch: {
            'item.error': function (error) {
                if (error && !this.item.compressing) {
                    const n = new Noty({
                        ...notyOption,
                        text: 'Error occurred while downloading, retry?',
                        buttons: [
                            Noty.button('SKIP', 'btn btn-noty', () => {
                                n.close();
                                dlQueue.skipFromError();
                            }),
                            Noty.button('YES', 'btn btn-noty-green btn-noty', () => {
                                n.close();
                                this.item.error = false;
                                dlQueue.restartFromError();
                            }),
                        ],
                    });
                    n.show();
                }
            },
        },
        methods: {
            cancel() {
                if (this.index === 0) {
                    dlQueue.skip = true;
                } else {
                    const { info } = dlQueue.queue.remove(this.index);
                    if (info && typeof info.cancel === 'function') info.cancel();
                }
            },
        },
        template: '<div class="download-item" :class="{ \'download-error\': item.error, \'download-compressing\': item.compressing && !item.error, \'can-cancel\': canCancel }" :title="item.title"><div class="download-item-cancel" v-if="canCancel" @click="cancel"><i class="fa fa-times"></i></div><div class="download-item-title">{{item.title}}</div><div class="download-item-progress" :style="{ width: `${width}%` }"><div class="download-item-progress-text">{{ width }}%</div></div></div>',
    });
    Vue.component('download-list', {
        props: ['zipList', 'dlList'],
        template: '<div id="download-panel"><download-item v-for="(item, index) in zipList" :item="item" :index="index" :key="index" /><download-item v-for="(item, index) in dlList" :item="item" :index="index" :key="index" /></div>',
    });
    new Vue({
        el: '#download-panel',
        // TODO: 两个都改造
        data: {
            dlQueue: dlQueue.queue,
            zipQueue: zipQueue.queue,
        },
        computed: {
            zipList() {
                return this.zipQueue.map(({ info }) => info);
            },
            dlList() {
                return this.dlQueue.map(({ info }) => info);
            },
            infoList() {
                return [...this.zipList, ...this.dlList];
            },
        },
        created() {
            window.addEventListener('beforeunload', event => {
                if (!this.infoList.length) return;
                event.preventDefault();
                event.returnValue = '';
            });
        },
        watch: {
            infoList(val) {
                sessionStorage.setItem('queueInfos', JSON.stringify(val));
            },
        },
        template: '<download-list v-if="infoList.length" :zipList="zipList" :dlList="dlList" />',
    });

    // 网络请求
    const get = (url, responseType = 'json', retry = 3) =>
        new Promise((resolve, reject) => {
            try {
                GM_xmlhttpRequest({
                    method: 'GET',
                    url,
                    responseType,
                    onerror: e => {
                        if (retry === 0) reject(e);
                        else {
                            _warn('Network error, retry.');
                            setTimeout(() => {
                                resolve(get(url, responseType, retry - 1));
                            }, 1000);
                        }
                    },
                    onload: ({ status, response }) => {
                        if (status === 200) resolve(response);
                        else if (retry === 0) reject(new Error(`${status} ${url}`));
                        else {
                            _warn(status, url);
                            setTimeout(() => {
                                resolve(get(url, responseType, retry - 1));
                            }, 500);
                        }
                    },
                });
            } catch (error) {
                reject(error);
            }
        });
    const proxyGetJSON = url => get(`https://json2jsonp.com/?url=${encodeURIComponent(url)}&callback=cbfunc`, '').then(jsonp => JSON.parse(jsonp.replace(/^cbfunc\((.*)\)$/, '$1')));
    const nhentaiGalleryApi = gid => {
        const url = `https://nhentai.net/api/gallery/${gid}`;
        return isNyaHentai ? proxyGetJSON(url) : get(url);
    };
    const getDownloadURL = (mid, filename) => `https://${isNyaHentai ? 'i0.mspcdn9.xyz' : 'i.nhentai.net'}/galleries/${mid}/${filename}`;

    // 伪多线程
    const multiThread = async (tasks, promiseFunc) => {
        const threads = [];
        let taskIndex = 0;

        const run = async threadID => {
            while (true) {
                const i = taskIndex++;
                if (i >= tasks.length) break;
                await promiseFunc(tasks[i], threadID);
            }
        };

        // 创建线程
        for (let threadID = 0; threadID < THREAD; threadID++) {
            await sleep(Math.min(2000 / THREAD, 300));
            threads.push(run(threadID));
        }
        return Promise.all(threads);
    };

    // 获取本子信息
    const getGallery = async gid => {
        const gallery = unsafeWindow.gallery;
        const {
            id,
            media_id,
            title: { english, japanese, pretty },
            images: { pages },
            num_pages,
        } = gid ? await nhentaiGalleryApi(gid) : typeof gallery === 'undefined' ? await nhentaiGalleryApi((gid = /\/g\/([0-9]+)/.exec(window.location.pathname)[1])) : (gid = gallery.id) && gallery;

        const p = [];
        pages.forEach((page, i) => {
            p.push({
                i: i + 1,
                t: getExtension(page),
            });
        });

        const info = {
            gid,
            mid: media_id,
            title: japanese || english,
            pages: p,
            cfName: getTextFromTemplate(CF_NAME, {
                english,
                japanese: japanese || english,
                pretty,
                id,
                pages: num_pages,
            }),
        };
        _log(info);

        return info;
    };

    // 下载本子
    const downloadGallery = async ({ mid, pages, cfName }, $btn = null, $btnTxt = null, headTxt = false, rangeChecks) => {
        if (rangeChecks && rangeChecks.length) {
            pages = pages.filter(({ i }) => rangeChecks.some(check => check(i)));
        }

        const info = (dlQueue.queue[0] && dlQueue.queue[0].info) || {};
        info.done = 0;
        const zip = await new JSZip();

        const btnDownloadProgress = () => {
            if ($btnTxt) $btnTxt.text(`${headTxt ? `Download ${getDpDlExt()} ` : ''}${info.done}/${pages.length}`);
        };
        const btnCompressingProgress = (percent = 0) => {
            if ($btnTxt) $btnTxt.text(`${headTxt ? 'Compressing ' : ''}${percent.toFixed()}%`);
        };

        btnDownloadProgress();

        const dlPromise = (page, threadID) => {
            if (info.error || dlQueue.skip) return;
            const url = CUSTOM_DOWNLOAD_URL ? getTextFromTemplate(CUSTOM_DOWNLOAD_URL, { mid, index: page.i, ext: page.t }) : getDownloadURL(mid, `${page.i}.${page.t}`);
            _log(`[${threadID}] ${url}`);
            return get(url, 'arraybuffer')
                .then(async data => {
                    zip.file(`${String(page.i).padStart(FILENAME_LENGTH, 0)}.${page.t}`, data);
                    info.done++;
                    btnDownloadProgress();
                })
                .catch(e => {
                    info.error = true;
                    throw e;
                });
        };

        await multiThread(pages, dlPromise);

        if (dlQueue.skip) {
            dlQueue.skip = false;
            if ($btnTxt) $btnTxt.text(`${headTxt ? `Download ${getDpDlExt()} ` : ''}`);
            if ($btn) $btn.attr('disabled', false);
            return {
                zipFn: async () => ({}),
                zipInfo: null,
            };
        }

        return {
            zipFn: async () => {
                info.compressing = true;
                btnCompressingProgress();
                _log('Compressing', cfName);
                let lastZipFile = '';
                const data = await zip.generateAsync(
                    {
                        type: 'arraybuffer',
                        ...getCompressionOptions(),
                    },
                    ({ workerId, percent, currentFile }) => {
                        if (lastZipFile !== currentFile && currentFile) {
                            lastZipFile = currentFile;
                            _log(`[${workerId}] Compressing ${percent.toFixed(2)}%`, currentFile);
                        }
                        btnCompressingProgress(percent);
                        info.compressingPercent = percent;
                    }
                );
                _log('Done');

                if ($btnTxt) $btnTxt.text(`${headTxt ? `Download ${getDpDlExt()} ` : ''}✓`);
                if ($btn) $btn.attr('disabled', false);

                return new File([data], cfName, { type: 'application/zip' });
            },
            zipInfo: info,
        };
    };
    const downloadG = async (gid, $btn = null, $btnTxt = null, headTxt = '') => downloadGallery(await getGallery(gid), $btn, $btnTxt, headTxt);

    // 语言过滤
    const langFilter = (lang, $node) => {
        const getNode = $node ? selector => $node.find(selector) : selector => $(selector);
        if (Number(lang) === 0) getNode('.gallery').removeClass('hidden');
        else {
            getNode(`.gallery[data-tags~=${lang}]`).removeClass('hidden');
            getNode(`.gallery:not([data-tags~=${lang}])`).addClass('hidden');
        }
    };

    // 本子浏览模式
    const applyGPViewStyle = gpViewMode => {
        if (gpViewMode) $('body').append(`<style id="gp-view-mode-style">#image-container img{width:auto;max-width:calc(100vw - 20px);max-height:${isNyaHentai ? 'calc(100vh - 65px)' : '100vh'}}</style>`);
        else $('#gp-view-mode-style').remove();
    };

    // 功能初始化
    const init = () => {
        if (pageType.gallery) {
            // 本子详情页
            const $btnTxt = $(`<span class="download-zip-txt">Download ${getDpDlExt()}</span>`);
            const $btn = $('<button class="btn btn-secondary download-zip"><i class="fa fa-download"></i> </button>').append($btnTxt);
            const $pagesInput = $('<input class="pages-input" placeholder="Download pages (e.g. 1-10,12,14,18-)">');
            $('#info > .buttons').append($btn).after($pagesInput);

            let zip, pagesInput, info;

            $btn.on('click', async () => {
                const rangeChecks = $pagesInput
                    .val()
                    .split(',')
                    .filter(range => parseInt(range))
                    .map(range => {
                        const [start, end] = range.split('-').map(num => parseInt(num));
                        if (typeof end === 'undefined') return page => page === start;
                        else if (Number.isNaN(end)) return page => page >= start;
                        else return page => start <= page && page <= end;
                    });

                $btn.attr('disabled', true);

                try {
                    if (!info) info = await getGallery();

                    const downloaded = (await isDownloadedByGid(info.gid)) || (await isDownloadedByTitle(info.title));

                    if (downloaded && !(await downloadAgainConfirm(info.title))) {
                        $btn.attr('disabled', false);
                        return;
                    }

                    if (!zip || pagesInput !== $pagesInput.val()) {
                        zip = await (await downloadGallery(info, $btn, $btnTxt, true, rangeChecks)).zipFn();
                        pagesInput = $pagesInput.val();
                    }
                    if (!zip) return;
                    saveAs(zip);
                    markAsDownloaded(info.gid, info.title);
                } catch (error) {
                    $btn.attr('disabled', false);
                    $btnTxt.text('Error');
                    _error(error);
                }
            });
        } else if (pageType.list) {
            // 语言过滤
            const $langFilter = $('<select id="lang-filter"><option value="0">None</option><option value="29963">Chinese</option><option value="6346">Japanese</option><option value="12227">English</option></select>');
            $('ul.menu.left').append($('<li style="padding:0 10px;user-select:none">Filter: </li>').append($langFilter));
            $langFilter.on('change', function () {
                langFilter(this.value);
                sessionStorage.setItem('lang-filter', this.value);
            });

            // 本子列表页
            $('.gallery').each(handleGallery);
            new MutationObserver(mutations => {
                mutations.forEach(({ addedNodes }) => {
                    addedNodes.forEach(node => {
                        const $node = $(node);
                        $node.find('.gallery').each(handleGallery);
                        (val => val && langFilter(val, $node))($langFilter.val());
                    });
                });
            }).observe($('#content')[0], { childList: true });

            function handleGallery() {
                const $gallery = $(this);

                const $a = $gallery.find('a.cover');
                if (OPEN_ON_NEW_TAB) $a.attr('target', '_blank');
                const gid = /[0-9]+/.exec($a.attr('href'))[0];

                const $btnTxt = $('<span class="download-zip-txt"></span>');
                const $btn = $('<button class="btn btn-secondary download-zip"><i class="fa fa-download"></i> </button>').append($btnTxt);
                $gallery.prepend($btn);

                const cancel = () => {
                    $btn.attr('disabled', false);
                    $btnTxt.text('');
                };
                const markGalleryDownloaded = () => {
                    $gallery.addClass('downloaded');
                };

                isDownloadedByGid(gid).then(downloaded => downloaded && markGalleryDownloaded());

                $btn.on('click', () => {
                    let skipDownloadedCheck = false;
                    (async function startDownload() {
                        $btn.attr('disabled', true);
                        $btnTxt.text('Wait');
                        if (!skipDownloadedCheck && (await isDownloadedByGid(gid))) {
                            const continueDownload = await downloadAgainConfirm($gallery.find('.caption').text());
                            if (!continueDownload) {
                                cancel();
                                return;
                            }
                            skipDownloadedCheck = true;
                        }
                        let gallery;
                        try {
                            gallery = await getGallery(gid);
                        } catch (e) {
                            _error(e);
                            $btn.attr('disabled', false);
                            $btnTxt.text('Error');
                            const n = new Noty({
                                ...notyOption,
                                text: 'Error occurred while getting information, retry?',
                                buttons: [
                                    Noty.button('No', 'btn btn-noty', () => {
                                        n.close();
                                    }),
                                    Noty.button('YES', 'btn btn-noty-green btn-noty', () => {
                                        n.close();
                                        startDownload();
                                    }),
                                ],
                            });
                            n.show();
                        }
                        if (!skipDownloadedCheck && ((await isDownloadedByTitle(gallery.title)) || dlQueue.queue.some(({ info: { title } }) => title === gallery.title))) {
                            const continueDownload = await downloadAgainConfirm(gallery.title);
                            if (!continueDownload) {
                                cancel();
                                return;
                            }
                        }
                        dlQueue.push(
                            async () => {
                                const { zipFn, zipInfo } = await downloadGallery(gallery, $btn, $btnTxt);
                                if (zipInfo) {
                                    zipQueue.push(async () => {
                                        const zip = await zipFn();
                                        if (!zip) {
                                            cancel();
                                            return;
                                        }
                                        saveAs(zip);
                                        markAsDownloaded(gid, gallery.title);
                                        markGalleryDownloaded();
                                    }, zipInfo);
                                    zipQueue.start();
                                }
                            },
                            {
                                gid,
                                title: gallery.title,
                                page: gallery.pages.length,
                                done: 0,
                                error: false,
                                compressing: false,
                                compressingPercent: 0,
                                cancel,
                            }
                        );
                        dlQueue.start();
                    })();
                });
            }

            // 左右键翻页
            $(document).on('keydown', event => {
                switch (event.key) {
                    case 'ArrowLeft':
                        $('.pagination .previous').trigger('click');
                        break;
                    case 'ArrowRight':
                        $('.pagination .next').trigger('click');
                        break;
                }
            });

            // 还原记住的语言过滤
            const rememberedLANG = sessionStorage.getItem('lang-filter');
            if (rememberedLANG) {
                $langFilter.val(rememberedLANG);
                langFilter(rememberedLANG);
            }

            // 还原下载队列
            const dlQueueInfos = JSON.parse(sessionStorage.getItem('queueInfos'));
            if (dlQueueInfos) {
                for (const info of dlQueueInfos) {
                    const { gid, title } = info;
                    dlQueue.push(async () => {
                        const { zipFn, zipInfo } = await downloadG(gid);
                        if (zipInfo) {
                            zipQueue.push(async () => {
                                const zip = await zipFn();
                                if (!zip) return;
                                saveAs(zip);
                                markAsDownloaded(gid, title);
                            }, zipInfo);
                            zipQueue.start();
                        }
                    }, info);
                }
            }
            dlQueue.start();
        } else if (pageType.galleryPage && isNyaHentai) {
            // 本子在线阅读
            const gpViewModeText = ['[off]', '[on]'];
            let gpViewMode = GM_getValue('gp_view_mode', 0);
            applyGPViewStyle(gpViewMode);
            $('#page-container').prepend(`<button id="gp-view-mode-btn" class="btn btn-secondary"><i class="fa fa-arrows-v"></i> <span>100% view height</span> <span id="gp-view-mode-switch-text">${gpViewModeText[gpViewMode]}</span></button>`);
            const $gpvmst = $('#gp-view-mode-switch-text');
            $('#gp-view-mode-btn').on('click', () => {
                gpViewMode = 1 - gpViewMode;
                GM_setValue('gp_view_mode', gpViewMode);
                $gpvmst.text(gpViewModeText[gpViewMode]);
                applyGPViewStyle(gpViewMode);
            });
        }
    };

    $(document).pjax('.pagination a, .sort a', { container: '#content', fragment: '#content', timeout: 10000 });
    $(document).on('pjax:end', () => {
        // 防止翻页出现 pjax 参数
        $('.pagination a').each(function () {
            const $this = $(this);
            const href = $this.attr('href');
            const isRelative = href.startsWith('/');
            const url = new URL(isRelative ? `${location.protocol}//${location.host}${href}` : href);
            url.searchParams.delete('_pjax');
            $this.attr('href', isRelative ? `${url.pathname}${url.search}` : url.href);
        });
        // 加载 lazyload 图片
        const { App } = unsafeWindow;
        if (typeof App !== 'undefined') App.prototype.install_lazy_loader();
    });
    init();
})();