NodeBB/NodeBB

'use strict';

const nconf = require('nconf');
const qs = require('querystring');
const validator = require('validator');

const user = require('../user');
const meta = require('../meta');
const topics = require('../topics');
const categories = require('../categories');
const posts = require('../posts');
const privileges = require('../privileges');
const helpers = require('./helpers');
const pagination = require('../pagination');
const utils = require('../utils');
const analytics = require('../analytics');

const topicsController = module.exports;

const url = nconf.get('url');
const relative_path = nconf.get('relative_path');
const upload_url = nconf.get('upload_url');
const validSorts = ['oldest_to_newest', 'newest_to_oldest', 'most_votes'];

topicsController.get = async function getTopic(req, res, next) {
    const tid = req.params.topic_id;
    if (
        (req.params.post_index && !utils.isNumber(req.params.post_index) && req.params.post_index !== 'unread') ||
        !utils.isNumber(tid)
    ) {
        return next();
    }
    let postIndex = parseInt(req.params.post_index, 10) || 1;
    const [
        userPrivileges,
        settings,
        topicData,
        rssToken,
    ] = await Promise.all([
        privileges.topics.get(tid, req.uid),
        user.getSettings(req.uid),
        topics.getTopicData(tid),
        user.auth.getFeedToken(req.uid),
    ]);

    let currentPage = parseInt(req.query.page, 10) || 1;
    const pageCount = Math.max(1, Math.ceil((topicData && topicData.postcount) / settings.postsPerPage));
    const invalidPagination = (settings.usePagination && (currentPage < 1 || currentPage > pageCount));
    if (
        !topicData ||
        userPrivileges.disabled ||
        invalidPagination ||
        (topicData.scheduled && !userPrivileges.view_scheduled)
    ) {
        return next();
    }

    if (!userPrivileges['topics:read'] || (!topicData.scheduled && topicData.deleted && !userPrivileges.view_deleted)) {
        return helpers.notAllowed(req, res);
    }

    if (req.params.post_index === 'unread') {
        postIndex = await topics.getUserBookmark(tid, req.uid);
    }

    if (!res.locals.isAPI && (!req.params.slug || topicData.slug !== `${tid}/${req.params.slug}`) && (topicData.slug && topicData.slug !== `${tid}/`)) {
        return helpers.redirect(res, `/topic/${topicData.slug}${postIndex ? `/${postIndex}` : ''}${generateQueryString(req.query)}`, true);
    }

    if (utils.isNumber(postIndex) && topicData.postcount > 0 && (postIndex < 1 || postIndex > topicData.postcount)) {
        return helpers.redirect(res, `/topic/${tid}/${req.params.slug}${postIndex > topicData.postcount ? `/${topicData.postcount}` : ''}${generateQueryString(req.query)}`);
    }
    postIndex = Math.max(1, postIndex);
    const sort = validSorts.includes(req.query.sort) ? req.query.sort : settings.topicPostSort;
    const set = sort === 'most_votes' ? `tid:${tid}:posts:votes` : `tid:${tid}:posts`;
    const reverse = sort === 'newest_to_oldest' || sort === 'most_votes';

    if (!req.query.page) {
        currentPage = calculatePageFromIndex(postIndex, settings);
    }
    if (settings.usePagination && req.query.page) {
        const top = ((currentPage - 1) * settings.postsPerPage) + 1;
        const bottom = top + settings.postsPerPage;
        if (!req.params.post_index || (postIndex < top || postIndex > bottom)) {
            postIndex = top;
        }
    }
    const { start, stop } = calculateStartStop(currentPage, postIndex, settings);

    await topics.getTopicWithPosts(topicData, set, req.uid, start, stop, reverse);

    topics.modifyPostsByPrivilege(topicData, userPrivileges);
    topicData.tagWhitelist = categories.filterTagWhitelist(topicData.tagWhitelist, userPrivileges.isAdminOrMod);

    topicData.privileges = userPrivileges;
    topicData.topicStaleDays = meta.config.topicStaleDays;
    topicData['reputation:disabled'] = meta.config['reputation:disabled'];
    topicData['downvote:disabled'] = meta.config['downvote:disabled'];
    topicData['feeds:disableRSS'] = meta.config['feeds:disableRSS'] || 0;
    topicData['signatures:hideDuplicates'] = meta.config['signatures:hideDuplicates'];
    topicData.bookmarkThreshold = meta.config.bookmarkThreshold;
    topicData.necroThreshold = meta.config.necroThreshold;
    topicData.postEditDuration = meta.config.postEditDuration;
    topicData.postDeleteDuration = meta.config.postDeleteDuration;
    topicData.scrollToMyPost = settings.scrollToMyPost;
    topicData.updateUrlWithPostIndex = settings.updateUrlWithPostIndex;
    topicData.allowMultipleBadges = meta.config.allowMultipleBadges === 1;
    topicData.privateUploads = meta.config.privateUploads === 1;
    topicData.showPostPreviewsOnHover = meta.config.showPostPreviewsOnHover === 1;
    topicData.sortOptionLabel = `[[topic:${validator.escape(String(sort)).replace(/_/g, '-')}]]`;
    if (!meta.config['feeds:disableRSS']) {
        topicData.rssFeedUrl = `${relative_path}/topic/${topicData.tid}.rss`;
        if (req.loggedIn) {
            topicData.rssFeedUrl += `?uid=${req.uid}&token=${rssToken}`;
        }
    }

    topicData.postIndex = postIndex;

    const [author] = await Promise.all([
        user.getUserFields(topicData.uid, ['username', 'userslug']),
        buildBreadcrumbs(topicData),
        addOldCategory(topicData, userPrivileges),
        addTags(topicData, req, res, currentPage),
        incrementViewCount(req, tid),
        markAsRead(req, tid),
        analytics.increment([`pageviews:byCid:${topicData.category.cid}`]),
    ]);

    topicData.author = author;
    topicData.pagination = pagination.create(currentPage, pageCount, req.query);
    topicData.pagination.rel.forEach((rel) => {
        rel.href = `${url}/topic/${topicData.slug}${rel.href}`;
        res.locals.linkTags.push(rel);
    });
    res.render('topic', topicData);
};

function generateQueryString(query) {
    const qString = qs.stringify(query);
    return qString.length ? `?${qString}` : '';
}

function calculatePageFromIndex(postIndex, settings) {
    return 1 + Math.floor((postIndex - 1) / settings.postsPerPage);
}

function calculateStartStop(page, postIndex, settings) {
    let startSkip = 0;

    if (!settings.usePagination) {
        if (postIndex > 1) {
            page = 1;
        }
        startSkip = Math.max(0, postIndex - Math.ceil(settings.postsPerPage / 2));
    }

    const start = ((page - 1) * settings.postsPerPage) + startSkip;
    const stop = start + settings.postsPerPage - 1;
    return { start: Math.max(0, start), stop: Math.max(0, stop) };
}

async function incrementViewCount(req, tid) {
    const allow = req.uid > 0 || (meta.config.guestsIncrementTopicViews && req.uid === 0);
    if (allow) {
        req.session.tids_viewed = req.session.tids_viewed || {};
        const now = Date.now();
        const interval = meta.config.incrementTopicViewsInterval * 60000;
        if (!req.session.tids_viewed[tid] || req.session.tids_viewed[tid] < now - interval) {
            await topics.increaseViewCount(tid);
            req.session.tids_viewed[tid] = now;
        }
    }
}

async function markAsRead(req, tid) {
    if (req.loggedIn) {
        const markedRead = await topics.markAsRead([tid], req.uid);
        const promises = [topics.markTopicNotificationsRead([tid], req.uid)];
        if (markedRead) {
            promises.push(topics.pushUnreadCount(req.uid));
        }
        await Promise.all(promises);
    }
}

async function buildBreadcrumbs(topicData) {
    const breadcrumbs = [
        {
            text: topicData.category.name,
            url: `${url}/category/${topicData.category.slug}`,
            cid: topicData.category.cid,
        },
        {
            text: topicData.title,
        },
    ];
    const parentCrumbs = await helpers.buildCategoryBreadcrumbs(topicData.category.parentCid);
    topicData.breadcrumbs = parentCrumbs.concat(breadcrumbs);
}

async function addOldCategory(topicData, userPrivileges) {
    if (userPrivileges.isAdminOrMod && topicData.oldCid) {
        topicData.oldCategory = await categories.getCategoryFields(
            topicData.oldCid, ['cid', 'name', 'icon', 'bgColor', 'color', 'slug']
        );
    }
}

async function addTags(topicData, req, res, currentPage) {
    const postIndex = parseInt(req.params.post_index, 10) || 0;
    const postAtIndex = topicData.posts.find(p => parseInt(p.index, 10) === parseInt(Math.max(0, postIndex - 1), 10));
    let description = '';
    if (postAtIndex && postAtIndex.content) {
        description = utils.stripHTMLTags(utils.decodeHTMLEntities(postAtIndex.content)).trim();
    }

    if (description.length > 160) {
        description = `${description.slice(0, 157)}...`;
    }
    description = description.replace(/\n/g, ' ').trim();

    let mainPost = topicData.posts.find(p => parseInt(p.index, 10) === 0);
    if (!mainPost) {
        mainPost = await posts.getPostData(topicData.mainPid);
    }

    res.locals.metaTags = [
        {
            name: 'title',
            content: topicData.titleRaw,
        },
        {
            property: 'og:title',
            content: topicData.titleRaw,
        },
        {
            property: 'og:type',
            content: 'article',
        },
        {
            property: 'article:published_time',
            content: utils.toISOString(topicData.timestamp),
        },
        {
            property: 'article:modified_time',
            content: utils.toISOString(Math.max(topicData.lastposttime, mainPost && mainPost.edited)),
        },
        {
            property: 'article:section',
            content: topicData.category ? topicData.category.name : '',
        },
    ];

    if (description && description.length) {
        res.locals.metaTags.push(
            {
                name: 'description',
                content: description,
            },
            {
                property: 'og:description',
                content: description,
            },
        );
    }

    await addOGImageTags(res, topicData, postAtIndex);

    const page = currentPage > 1 ? `?page=${currentPage}` : '';
    res.locals.linkTags = [
        {
            rel: 'canonical',
            href: `${url}/topic/${topicData.slug}${page}`,
            noEscape: true,
        },
    ];

    if (!topicData['feeds:disableRSS']) {
        res.locals.linkTags.push({
            rel: 'alternate',
            type: 'application/rss+xml',
            href: topicData.rssFeedUrl,
        });
    }

    if (topicData.category) {
        res.locals.linkTags.push({
            rel: 'up',
            href: `${url}/category/${topicData.category.slug}`,
        });
    }

    if (postAtIndex) {
        res.locals.linkTags.push({
            rel: 'author',
            href: `${url}/user/${postAtIndex.user.userslug}`,
        });
    }
}

async function addOGImageTags(res, topicData, postAtIndex) {
    const uploads = postAtIndex ? await posts.uploads.listWithSizes(postAtIndex.pid) : [];
    const images = uploads.map((upload) => {
        upload.name = `${url + upload_url}/${upload.name}`;
        return upload;
    });
    if (topicData.thumbs) {
        const path = require('path');
        const thumbs = topicData.thumbs.filter(
            t => t && images.every(img => path.normalize(img.name) !== path.normalize(url + t.url))
        );
        images.push(...thumbs.map(thumbObj => ({ name: url + thumbObj.url })));
    }
    if (topicData.category.backgroundImage && (!postAtIndex || !postAtIndex.index)) {
        images.push(topicData.category.backgroundImage);
    }
    if (postAtIndex && postAtIndex.user && postAtIndex.user.picture) {
        images.push(postAtIndex.user.picture);
    }
    images.forEach(path => addOGImageTag(res, path));
}

function addOGImageTag(res, image) {
    let imageUrl;
    if (typeof image === 'string' && !image.startsWith('http')) {
        imageUrl = url + image.replace(new RegExp(`^${relative_path}`), '');
    } else if (typeof image === 'object') {
        imageUrl = image.name;
    } else {
        imageUrl = image;
    }

    res.locals.metaTags.push({
        property: 'og:image',
        content: imageUrl,
        noEscape: true,
    }, {
        property: 'og:image:url',
        content: imageUrl,
        noEscape: true,
    });

    if (typeof image === 'object' && image.width && image.height) {
        res.locals.metaTags.push({
            property: 'og:image:width',
            content: String(image.width),
        }, {
            property: 'og:image:height',
            content: String(image.height),
        });
    }
}

topicsController.teaser = async function (req, res, next) {
    const tid = req.params.topic_id;
    if (!utils.isNumber(tid)) {
        return next();
    }
    const canRead = await privileges.topics.can('topics:read', tid, req.uid);
    if (!canRead) {
        return res.status(403).json('[[error:no-privileges]]');
    }
    const pid = await topics.getLatestUndeletedPid(tid);
    if (!pid) {
        return res.status(404).json('not-found');
    }
    const postData = await posts.getPostSummaryByPids([pid], req.uid, { stripTags: false });
    if (!postData.length) {
        return res.status(404).json('not-found');
    }
    res.json(postData[0]);
};

topicsController.pagination = async function (req, res, next) {
    const tid = req.params.topic_id;
    const currentPage = parseInt(req.query.page, 10) || 1;

    if (!utils.isNumber(tid)) {
        return next();
    }

    const [userPrivileges, settings, topic] = await Promise.all([
        privileges.topics.get(tid, req.uid),
        user.getSettings(req.uid),
        topics.getTopicData(tid),
    ]);

    if (!topic) {
        return next();
    }

    if (!userPrivileges.read || !privileges.topics.canViewDeletedScheduled(topic, userPrivileges)) {
        return helpers.notAllowed(req, res);
    }

    const postCount = topic.postcount;
    const pageCount = Math.max(1, Math.ceil(postCount / settings.postsPerPage));

    const paginationData = pagination.create(currentPage, pageCount);
    paginationData.rel.forEach((rel) => {
        rel.href = `${url}/topic/${topic.slug}${rel.href}`;
    });

    res.json({ pagination: paginationData });
};