NodeBB/NodeBB

'use strict';

module.exports = function (module) {
    module.sortedSetUnionCard = async function (keys) {
        if (!Array.isArray(keys) || !keys.length) {
            return 0;
        }

        const data = await module.client.collection('objects').aggregate([
            { $match: { _key: { $in: keys } } },
            { $group: { _id: { value: '$value' } } },
            { $group: { _id: null, count: { $sum: 1 } } },
        ]).toArray();
        return Array.isArray(data) && data.length ? data[0].count : 0;
    };

    module.getSortedSetUnion = async function (params) {
        params.sort = 1;
        return await getSortedSetUnion(params);
    };

    module.getSortedSetRevUnion = async function (params) {
        params.sort = -1;
        return await getSortedSetUnion(params);
    };

    async function getSortedSetUnion(params) {
        if (!Array.isArray(params.sets) || !params.sets.length) {
            return [];
        }
        let limit = params.stop - params.start + 1;
        if (limit <= 0) {
            limit = 0;
        }

        const aggregate = {};
        if (params.aggregate) {
            aggregate[`$${params.aggregate.toLowerCase()}`] = '$score';
        } else {
            aggregate.$sum = '$score';
        }

        const pipeline = [
            { $match: { _key: { $in: params.sets } } },
            { $group: { _id: { value: '$value' }, totalScore: aggregate } },
            { $sort: { totalScore: params.sort, _id: 1 } },
        ];

        if (params.start) {
            pipeline.push({ $skip: params.start });
        }

        if (limit > 0) {
            pipeline.push({ $limit: limit });
        }

        const project = { _id: 0, value: '$_id.value' };
        if (params.withScores) {
            project.score = '$totalScore';
        }
        pipeline.push({ $project: project });

        let data = await module.client.collection('objects').aggregate(pipeline).toArray();
        if (!params.withScores) {
            data = data.map(item => item.value);
        }
        return data;
    }
};