NodeBB/NodeBB

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src/topics/teaser.js

Summary

Maintainability
C
1 day
Test Coverage

'use strict';

const _ = require('lodash');

const db = require('../database');
const meta = require('../meta');
const user = require('../user');
const posts = require('../posts');
const plugins = require('../plugins');
const utils = require('../utils');

module.exports = function (Topics) {
    Topics.getTeasers = async function (topics, options) {
        if (!Array.isArray(topics) || !topics.length) {
            return [];
        }
        let uid = options;
        let { teaserPost } = meta.config;
        if (typeof options === 'object') {
            uid = options.uid;
            teaserPost = options.teaserPost || meta.config.teaserPost;
        }

        const counts = [];
        const teaserPids = [];
        const tidToPost = {};

        topics.forEach((topic) => {
            counts.push(topic && topic.postcount);
            if (topic) {
                if (topic.teaserPid === 'null') {
                    delete topic.teaserPid;
                }
                if (teaserPost === 'first') {
                    teaserPids.push(topic.mainPid);
                } else if (teaserPost === 'last-post') {
                    teaserPids.push(topic.teaserPid || topic.mainPid);
                } else { // last-reply and everything else uses teaserPid like `last` that was used before
                    teaserPids.push(topic.teaserPid);
                }
            }
        });

        const [allPostData, callerSettings] = await Promise.all([
            posts.getPostsFields(teaserPids, ['pid', 'uid', 'timestamp', 'tid', 'content']),
            user.getSettings(uid),
        ]);
        let postData = allPostData.filter(post => post && post.pid);
        postData = await handleBlocks(uid, postData);
        postData = postData.filter(Boolean);
        const uids = _.uniq(postData.map(post => post.uid));
        const sortNewToOld = callerSettings.topicPostSort === 'newest_to_oldest';
        const usersData = await user.getUsersFields(uids, ['uid', 'username', 'userslug', 'picture']);

        const users = {};
        usersData.forEach((user) => {
            users[user.uid] = user;
        });
        postData.forEach((post) => {
            // If the post author isn't represented in the retrieved users' data,
            // then it means they were deleted, assume guest.
            if (!users.hasOwnProperty(post.uid)) {
                post.uid = 0;
            }

            post.user = users[post.uid];
            post.timestampISO = utils.toISOString(post.timestamp);
            tidToPost[post.tid] = post;
        });
        await Promise.all(postData.map(p => posts.parsePost(p)));

        const { tags } = await plugins.hooks.fire('filter:teasers.configureStripTags', {
            tags: utils.stripTags.slice(0),
        });

        const teasers = topics.map((topic, index) => {
            if (!topic) {
                return null;
            }
            if (tidToPost[topic.tid]) {
                tidToPost[topic.tid].index = calcTeaserIndex(teaserPost, counts[index], sortNewToOld);
                if (tidToPost[topic.tid].content) {
                    tidToPost[topic.tid].content = utils.stripHTMLTags(replaceImgWithAltText(tidToPost[topic.tid].content), tags);
                }
            }
            return tidToPost[topic.tid];
        });

        const result = await plugins.hooks.fire('filter:teasers.get', { teasers: teasers, uid: uid });
        return result.teasers;
    };

    function calcTeaserIndex(teaserPost, postCountInTopic, sortNewToOld) {
        if (teaserPost === 'first') {
            return 1;
        }

        if (sortNewToOld) {
            return Math.min(2, postCountInTopic);
        }
        return postCountInTopic;
    }

    function replaceImgWithAltText(str) {
        return String(str).replace(/<img .*?alt="(.*?)"[^>]*>/gi, '$1');
    }

    async function handleBlocks(uid, teasers) {
        const blockedUids = await user.blocks.list(uid);
        if (!blockedUids.length) {
            return teasers;
        }

        return await Promise.all(teasers.map(async (postData) => {
            if (blockedUids.includes(parseInt(postData.uid, 10))) {
                return await getPreviousNonBlockedPost(postData, blockedUids);
            }
            return postData;
        }));
    }

    async function getPreviousNonBlockedPost(postData, blockedUids) {
        let isBlocked = false;
        let prevPost = postData;
        const postsPerIteration = 5;
        let start = 0;
        let stop = start + postsPerIteration - 1;
        let checkedAllReplies = false;

        function checkBlocked(post) {
            const isPostBlocked = blockedUids.includes(parseInt(post.uid, 10));
            prevPost = !isPostBlocked ? post : prevPost;
            return isPostBlocked;
        }

        do {
            /* eslint-disable no-await-in-loop */
            let pids = await db.getSortedSetRevRange(`tid:${postData.tid}:posts`, start, stop);
            if (!pids.length) {
                checkedAllReplies = true;
                const mainPid = await Topics.getTopicField(postData.tid, 'mainPid');
                pids = [mainPid];
            }
            const prevPosts = await posts.getPostsFields(pids, ['pid', 'uid', 'timestamp', 'tid', 'content']);
            isBlocked = prevPosts.every(checkBlocked);
            start += postsPerIteration;
            stop = start + postsPerIteration - 1;
        } while (isBlocked && prevPost && prevPost.pid && !checkedAllReplies);

        return prevPost;
    }

    Topics.getTeasersByTids = async function (tids, uid) {
        if (!Array.isArray(tids) || !tids.length) {
            return [];
        }
        const topics = await Topics.getTopicsFields(tids, ['tid', 'postcount', 'teaserPid', 'mainPid']);
        return await Topics.getTeasers(topics, uid);
    };

    Topics.getTeaser = async function (tid, uid) {
        const teasers = await Topics.getTeasersByTids([tid], uid);
        return Array.isArray(teasers) && teasers.length ? teasers[0] : null;
    };

    Topics.updateTeaser = async function (tid) {
        let pid = await Topics.getLatestUndeletedReply(tid);
        pid = pid || null;
        if (pid) {
            await Topics.setTopicField(tid, 'teaserPid', pid);
        } else {
            await Topics.deleteTopicField(tid, 'teaserPid');
        }
    };
};