salix/modules/ticket/back/methods/ticket-tracking/changeState.js

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

module.exports = Self => {
    Self.remoteMethodCtx('changeState', {
        description: 'Change the state of a ticket',
        accessType: 'WRITE',
        accepts: [
            {
                arg: 'data',
                description: 'Model instance data',
                type: 'Object',
                required: true,
                http: {source: 'body'}
            }
        ],
        returns: {
            type: 'Object',
            root: true
        },
        http: {
            path: `/changeState`,
            verb: 'POST'
        }
    });

    Self.changeState = async(ctx, params, options) => {
        const models = Self.app.models;
        const myOptions = {};
        let tx;

        if (typeof options == 'object')
            Object.assign(myOptions, options);

        if (!myOptions.transaction) {
            tx = await Self.beginTransaction({});
            myOptions.transaction = tx;
        }

        try {
            const userId = ctx.req.accessToken.userId;

            if (!params.stateFk && !params.code)
                throw new UserError('State cannot be blank');

            if (params.code) {
                const state = await models.State.findOne({
                    where: {code: params.code},
                    fields: ['id']
                }, myOptions);

                params.stateFk = state.id;
            }

            if (!params.workerFk) {
                const worker = await models.Worker.findOne({
                    where: {userFk: userId}
                }, myOptions);

                params.workerFk = worker.id;
            }

            const ticketState = await models.TicketState.findById(params.ticketFk, {
                fields: ['stateFk']
            }, myOptions);

            let oldStateAllowed;
            if (ticketState)
                oldStateAllowed = await models.State.isEditable(ctx, ticketState.stateFk, myOptions);
            const newStateAllowed = await models.State.isEditable(ctx, params.stateFk, myOptions);

            const isAllowed = (!ticketState || oldStateAllowed == true) && newStateAllowed == true;

            if (!isAllowed)
                throw new UserError(`You don't have enough privileges`, 'ACCESS_DENIED');

            const ticketTracking = await models.TicketTracking.create(params, myOptions);

            if (tx) await tx.commit();

            return ticketTracking;
        } catch (e) {
            if (tx) await tx.rollback();
            throw e;
        }
    };
};