salix/modules/item/back/methods/item/getWasteByWorker.js

module.exports = Self => {
    Self.remoteMethod('getWasteByWorker', {
        description: 'Returns the details of losses by worker',
        accessType: 'READ',
        accepts: [],
        returns: {
            type: ['Object'],
            root: true
        },
        http: {
            path: `/getWasteByWorker`,
            verb: 'GET'
        }
    });

    Self.getWasteByWorker = async() => {
        const wastes = await Self.rawSql(`
            SELECT *, 100 * dwindle / total AS percentage
            FROM (
                SELECT  buyer,
                        ws.family,
                        sum(ws.saleTotal) AS total,
                        sum(ws.saleWaste) AS dwindle
                    FROM bs.waste ws
                    WHERE year = YEAR(TIMESTAMPADD(WEEK,-1,CURDATE()))
                    AND week = WEEK(TIMESTAMPADD(WEEK,-1,CURDATE()), 1)
                    GROUP BY buyer, family
                ) sub
                ORDER BY percentage DESC`);

        const details = [];

        for (let waste of wastes) {
            const buyerName = waste.buyer;

            let buyerDetail = details.find(waste => {
                return waste.buyer == buyerName;
            });

            if (!buyerDetail) {
                buyerDetail = {
                    buyer: buyerName,
                    lines: []
                };
                details.push(buyerDetail);
            }

            buyerDetail.lines.push(waste);
        }

        return details;
    };
};