NodeBB/NodeBB

'use strict';

const nconf = require('nconf');
const winston = require('winston');

const plugins = require('../plugins');
const Meta = require('./index');
const utils = require('../utils');

const Tags = module.exports;

const url = nconf.get('url');
const relative_path = nconf.get('relative_path');
const upload_url = nconf.get('upload_url');

Tags.parse = async (req, data, meta, link) => {
    // Meta tags
    const defaultTags = [{
        name: 'viewport',
        content: 'width=device-width, initial-scale=1.0',
    }, {
        name: 'content-type',
        content: 'text/html; charset=UTF-8',
        noEscape: true,
    }, {
        name: 'apple-mobile-web-app-capable',
        content: 'yes',
    }, {
        name: 'mobile-web-app-capable',
        content: 'yes',
    }, {
        property: 'og:site_name',
        content: Meta.config.title || 'NodeBB',
    }, {
        name: 'msapplication-badge',
        content: `frequency=30; polling-uri=${url}/sitemap.xml`,
        noEscape: true,
    }, {
        name: 'theme-color',
        content: Meta.config.themeColor || '#ffffff',
    }];

    if (Meta.config.keywords) {
        defaultTags.push({
            name: 'keywords',
            content: Meta.config.keywords,
        });
    }

    if (Meta.config['brand:logo']) {
        defaultTags.push({
            name: 'msapplication-square150x150logo',
            content: Meta.config['brand:logo'],
            noEscape: true,
        });
    }

    const faviconPath = `${relative_path}/assets/uploads/system/favicon.ico`;
    const cacheBuster = `${Meta.config['cache-buster'] ? `?${Meta.config['cache-buster']}` : ''}`;

    // Link Tags
    const defaultLinks = [{
        rel: 'icon',
        type: 'image/x-icon',
        href: `${faviconPath}${cacheBuster}`,
    }, {
        rel: 'manifest',
        href: `${relative_path}/manifest.webmanifest`,
        crossorigin: `use-credentials`,
    }];

    if (plugins.hooks.hasListeners('filter:search.query')) {
        defaultLinks.push({
            rel: 'search',
            type: 'application/opensearchdescription+xml',
            title: utils.escapeHTML(String(Meta.config.title || Meta.config.browserTitle || 'NodeBB')),
            href: `${relative_path}/osd.xml`,
        });
    }

    // Touch icons for mobile-devices
    if (Meta.config['brand:touchIcon']) {
        defaultLinks.push({
            rel: 'apple-touch-icon',
            href: `${relative_path + upload_url}/system/touchicon-orig.png`,
        }, {
            rel: 'icon',
            sizes: '36x36',
            href: `${relative_path + upload_url}/system/touchicon-36.png`,
        }, {
            rel: 'icon',
            sizes: '48x48',
            href: `${relative_path + upload_url}/system/touchicon-48.png`,
        }, {
            rel: 'icon',
            sizes: '72x72',
            href: `${relative_path + upload_url}/system/touchicon-72.png`,
        }, {
            rel: 'icon',
            sizes: '96x96',
            href: `${relative_path + upload_url}/system/touchicon-96.png`,
        }, {
            rel: 'icon',
            sizes: '144x144',
            href: `${relative_path + upload_url}/system/touchicon-144.png`,
        }, {
            rel: 'icon',
            sizes: '192x192',
            href: `${relative_path + upload_url}/system/touchicon-192.png`,
        });
    } else {
        defaultLinks.push({
            rel: 'apple-touch-icon',
            href: `${relative_path}/assets/images/touch/512.png`,
        }, {
            rel: 'icon',
            sizes: '36x36',
            href: `${relative_path}/assets/images/touch/36.png`,
        }, {
            rel: 'icon',
            sizes: '48x48',
            href: `${relative_path}/assets/images/touch/48.png`,
        }, {
            rel: 'icon',
            sizes: '72x72',
            href: `${relative_path}/assets/images/touch/72.png`,
        }, {
            rel: 'icon',
            sizes: '96x96',
            href: `${relative_path}/assets/images/touch/96.png`,
        }, {
            rel: 'icon',
            sizes: '144x144',
            href: `${relative_path}/assets/images/touch/144.png`,
        }, {
            rel: 'icon',
            sizes: '192x192',
            href: `${relative_path}/assets/images/touch/192.png`,
        }, {
            rel: 'icon',
            sizes: '512x512',
            href: `${relative_path}/assets/images/touch/512.png`,
        });
    }

    const results = await utils.promiseParallel({
        tags: plugins.hooks.fire('filter:meta.getMetaTags', { req: req, data: data, tags: defaultTags }),
        links: plugins.hooks.fire('filter:meta.getLinkTags', { req: req, data: data, links: defaultLinks }),
    });

    meta = results.tags.tags.concat(meta || []).map((tag) => {
        if (!tag || typeof tag.content !== 'string') {
            winston.warn('Invalid meta tag. ', tag);
            return tag;
        }

        if (!tag.noEscape) {
            const attributes = Object.keys(tag);
            attributes.forEach((attr) => {
                tag[attr] = utils.escapeHTML(String(tag[attr]));
            });
        }

        return tag;
    });

    await addSiteOGImage(meta);

    addIfNotExists(meta, 'property', 'og:title', Meta.config.title || 'NodeBB');
    const ogUrl = url + (req.originalUrl !== '/' ? stripRelativePath(req.originalUrl) : '');
    addIfNotExists(meta, 'property', 'og:url', ogUrl);
    addIfNotExists(meta, 'name', 'description', Meta.config.description);
    addIfNotExists(meta, 'property', 'og:description', Meta.config.description);

    link = results.links.links.concat(link || []).map((tag) => {
        if (!tag.noEscape) {
            const attributes = Object.keys(tag);
            attributes.forEach((attr) => {
                tag[attr] = utils.escapeHTML(String(tag[attr]));
            });
        }

        return tag;
    });

    return { meta, link };
};

function addIfNotExists(meta, keyName, tagName, value) {
    let exists = false;
    meta.forEach((tag) => {
        if (tag[keyName] === tagName) {
            exists = true;
        }
    });

    if (!exists && value) {
        const data = {
            content: utils.escapeHTML(String(value)),
        };
        data[keyName] = tagName;
        meta.push(data);
    }
}

function stripRelativePath(url) {
    if (url.startsWith(relative_path)) {
        return url.slice(relative_path.length);
    }

    return url;
}

async function addSiteOGImage(meta) {
    const key = Meta.config['og:image'] ? 'og:image' : 'brand:logo';
    let ogImage = stripRelativePath(Meta.config[key] || '');
    if (ogImage && !ogImage.startsWith('http')) {
        ogImage = url + ogImage;
    }

    const { images } = await plugins.hooks.fire('filter:meta.addSiteOGImage', {
        images: [{
            url: ogImage || `${url}/assets/images/logo@3x.png`,
            width: ogImage ? Meta.config[`${key}:width`] : 963,
            height: ogImage ? Meta.config[`${key}:height`] : 225,
        }],
    });

    const properties = ['url', 'secure_url', 'type', 'width', 'height', 'alt'];
    images.forEach((image) => {
        for (const property of properties) {
            if (image.hasOwnProperty(property)) {
                switch (property) {
                    case 'url': {
                        meta.push({
                            property: 'og:image',
                            content: image.url,
                            noEscape: true,
                        }, {
                            property: 'og:image:url',
                            content: image.url,
                            noEscape: true,
                        });
                        break;
                    }

                    case 'secure_url': {
                        meta.push({
                            property: `og:${property}`,
                            content: image[property],
                            noEscape: true,
                        });
                        break;
                    }

                    case 'type':
                    case 'alt':
                    case 'width':
                    case 'height': {
                        meta.push({
                            property: `og:image:${property}`,
                            content: String(image[property]),
                        });
                    }
                }
            }
        }
    });
}