NodeBB/NodeBB

'use strict';

define('topicList', [
    'forum/infinitescroll',
    'handleBack',
    'topicSelect',
    'categoryFilter',
    'tagFilter',
    'forum/category/tools',
    'hooks',
], function (infinitescroll, handleBack, topicSelect, categoryFilter, tagFilter, categoryTools, hooks) {
    const TopicList = {};
    let templateName = '';

    let newTopicCount = 0;
    let newPostCount = 0;

    let loadTopicsCallback;
    let topicListEl;

    const scheduledTopics = [];

    $(window).on('action:ajaxify.start', function () {
        TopicList.removeListeners();
        categoryTools.removeListeners();
    });

    TopicList.init = function (template, cb) {
        topicListEl = findTopicListElement();

        templateName = template;
        loadTopicsCallback = cb || loadTopicsAfter;

        categoryTools.init();

        TopicList.watchForNewPosts();
        const states = ['watching', 'tracking'];
        if (ajaxify.data.selectedFilter && ajaxify.data.selectedFilter.filter === 'watched') {
            states.push('notwatching', 'ignoring');
        } else if (template !== 'unread') {
            states.push('notwatching');
        }

        categoryFilter.init($('[component="category/dropdown"]'), {
            states: states,
        });

        tagFilter.init($('[component="tag/filter"]'));

        if (!config.usePagination) {
            infinitescroll.init(TopicList.loadMoreTopics);
        }

        handleBack.init(function (after, handleBackCallback) {
            loadTopicsCallback(after, 1, function (data, loadCallback) {
                onTopicsLoaded(templateName, data.topics, ajaxify.data.showSelect, 1, function () {
                    handleBackCallback();
                    loadCallback();
                });
            });
        });

        if ($('body').height() <= $(window).height() && topicListEl.children().length >= 20) {
            $('#load-more-btn').show();
        }

        $('#load-more-btn').on('click', function () {
            TopicList.loadMoreTopics(1);
        });

        hooks.fire('action:topics.loaded', { topics: ajaxify.data.topics });
    };

    function findTopicListElement() {
        return $('[component="category"]').filter(function (i, e) {
            return !$(e).parents('[widget-area],[data-widget-area]').length;
        });
    }

    TopicList.watchForNewPosts = function () {
        newPostCount = 0;
        newTopicCount = 0;
        TopicList.removeListeners();
        socket.on('event:new_topic', onNewTopic);
        socket.on('event:new_post', onNewPost);
    };

    TopicList.removeListeners = function () {
        socket.removeListener('event:new_topic', onNewTopic);
        socket.removeListener('event:new_post', onNewPost);
    };

    function onNewTopic(data) {
        const d = ajaxify.data;

        const categories = d.selectedCids &&
            d.selectedCids.length &&
            d.selectedCids.indexOf(parseInt(data.cid, 10)) === -1;
        const filterWatched = d.selectedFilter &&
            d.selectedFilter.filter === 'watched';
        const category = d.template.category &&
            parseInt(d.cid, 10) !== parseInt(data.cid, 10);

        const preventAlert = !!(categories || filterWatched || category || scheduledTopics.includes(data.tid));
        hooks.fire('filter:topicList.onNewTopic', { topic: data, preventAlert }).then((result) => {
            if (result.preventAlert) {
                return;
            }

            if (data.scheduled && data.tid) {
                scheduledTopics.push(data.tid);
            }
            newTopicCount += 1;
            updateAlertText();
        });
    }

    function onNewPost(data) {
        const post = data.posts[0];
        if (!post || !post.topic || post.topic.isFollowing) {
            return;
        }

        const d = ajaxify.data;

        const isMain = parseInt(post.topic.mainPid, 10) === parseInt(post.pid, 10);
        const categories = d.selectedCids &&
            d.selectedCids.length &&
            d.selectedCids.indexOf(parseInt(post.topic.cid, 10)) === -1;
        const filterNew = d.selectedFilter &&
            d.selectedFilter.filter === 'new';
        const filterWatched = d.selectedFilter &&
            d.selectedFilter.filter === 'watched' &&
            !post.topic.isFollowing;
        const category = d.template.category &&
            parseInt(d.cid, 10) !== parseInt(post.topic.cid, 10);

        const preventAlert = !!(isMain || categories || filterNew || filterWatched || category);
        hooks.fire('filter:topicList.onNewPost', { post, preventAlert }).then((result) => {
            if (result.preventAlert) {
                return;
            }

            newPostCount += 1;
            updateAlertText();
        });
    }

    function updateAlertText() {
        if (newTopicCount > 0 || newPostCount > 0) {
            $('#new-topics-alert').removeClass('hide').fadeIn('slow');
            $('#category-no-topics').addClass('hide');
        }
    }

    TopicList.loadMoreTopics = function (direction) {
        if (!topicListEl.length || !topicListEl.children().length) {
            return;
        }
        const topics = topicListEl.find('[component="category/topic"]');
        const afterEl = direction > 0 ? topics.last() : topics.first();
        const after = (parseInt(afterEl.attr('data-index'), 10) || 0) + (direction > 0 ? 1 : 0);

        if (!utils.isNumber(after) || (after === 0 && topicListEl.find('[component="category/topic"][data-index="0"]').length)) {
            return;
        }

        loadTopicsCallback(after, direction, function (data, done) {
            onTopicsLoaded(templateName, data.topics, ajaxify.data.showSelect, direction, done);
        });
    };

    function calculateNextPage(after, direction) {
        return Math.floor(after / config.topicsPerPage) + (direction > 0 ? 1 : 0);
    }

    function loadTopicsAfter(after, direction, callback) {
        callback = callback || function () {};
        const query = utils.params();
        query.page = calculateNextPage(after, direction);
        infinitescroll.loadMoreXhr(query, callback);
    }

    function filterTopicsOnDom(topics) {
        return topics.filter(function (topic) {
            return !topicListEl.find('[component="category/topic"][data-tid="' + topic.tid + '"]').length;
        });
    }

    function onTopicsLoaded(templateName, topics, showSelect, direction, callback) {
        if (!topics || !topics.length) {
            $('#load-more-btn').hide();
            return callback();
        }
        topics = filterTopicsOnDom(topics);

        if (!topics.length) {
            $('#load-more-btn').hide();
            return callback();
        }

        let after;
        let before;
        const topicEls = topicListEl.find('[component="category/topic"]');

        if (direction > 0 && topics.length) {
            after = topicEls.last();
        } else if (direction < 0 && topics.length) {
            before = topicEls.first();
        }

        const tplData = {
            topics: topics,
            showSelect: showSelect,
            template: {
                name: templateName,
            },
        };
        tplData.template[templateName] = true;

        hooks.fire('action:topics.loading', { topics: topics, after: after, before: before });

        app.parseAndTranslate(templateName, 'topics', tplData, function (html) {
            topicListEl.removeClass('hidden');
            $('#category-no-topics').remove();

            if (after && after.length) {
                html.insertAfter(after);
            } else if (before && before.length) {
                const height = $(document).height();
                const scrollTop = $(window).scrollTop();

                html.insertBefore(before);

                $(window).scrollTop(scrollTop + ($(document).height() - height));
            } else {
                topicListEl.append(html);
            }

            if (!topicSelect.getSelectedTids().length) {
                infinitescroll.removeExtra(topicListEl.find('[component="category/topic"]'), direction, Math.max(60, config.topicsPerPage * 3));
            }

            html.find('.timeago').timeago();
            hooks.fire('action:topics.loaded', { topics: topics, template: templateName });
            callback();
        });
    }

    return TopicList;
});