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: 'string',
            root: true
        },
        http: {
            path: `/changeState`,
            verb: 'POST'
        }
    });

    Self.changeState = async(ctx, params) => {
        let userId = ctx.req.accessToken.userId;
        let models = Self.app.models;

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

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

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

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

        let oldStateAllowed = await models.State.isEditable(ctx, ticket.stateFk);
        let newStateAllowed = await models.State.isEditable(ctx, params.stateFk);

        let isAllowed = oldStateAllowed && newStateAllowed;

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

        return await models.TicketTracking.create(params);
    };
};