salix/modules/ticket/back/methods/sale/updateDiscount.js

let UserError = require('vn-loopback/util/user-error');

module.exports = Self => {
    Self.remoteMethod('updateDiscount', {
        description: 'Changes the discount of a sale',
        accessType: 'WRITE',
        accepts: [{
            arg: 'ticketFk',
            type: 'number',
            required: true,
            description: 'ticket id',
        }, {
            arg: 'sales',
            type: ['object'],
            required: true,
            description: 'sale ID, newDiscount, price, ticket',
        }],
        returns: {
            type: 'string',
            root: true
        },
        http: {
            path: `/updateDiscount`,
            verb: 'post'
        }
    });

    Self.updateDiscount = async(ticketFk, sales) => {
        const validDiscounts = sales.every(sale => {
            return !isNaN(sale.discount);
        });

        if (!validDiscounts)
            throw new UserError(`The value should be a number`);

        let model = Self.app.models;
        let ticket = await model.Ticket.findById(ticketFk, {
            include: {
                relation: 'client',
                scope: {
                    fields: ['salesPersonFk']
                }
            },
        });

        if (ticket.refFk)
            throw new UserError(`The sales of this ticket can't be modified`);

        let manaDiscount;
        let buyerDiscount = await model.ComponentRate.findOne({where: {code: 'buyerDiscount'}});
        let usesMana = await model.WorkerMana.findOne({where: {workerFk: ticket.client().salesPersonFk}, fields: 'amount'});
        let componentId = buyerDiscount.id;
        if (usesMana) {
            manaDiscount = await model.ComponentRate.findOne({where: {code: 'mana'}});
            componentId = manaDiscount.id;
        }

        for (let i = 0; i < sales.length; i++) {
            let currentLine = await model.Sale.findOne({where: {id: sales[i].id}, fields: 'price'});
            let value = ((-currentLine.price * sales[i].discount) / 100);

            await model.SaleComponent.upsert({saleFk: sales[i].id, value: value, componentFk: componentId});

            await model.Sale.update({id: sales[i].id}, {discount: sales[i].discount});
        }

        if (usesMana) {
            query = `call vn.manaSpellersRequery(?)`;

            await Self.rawSql(query, [ticket.client().salesPersonFk]);
        }
    };
};