salix/modules/ticket/back/methods/ticket-log/getChanges.js

module.exports = Self => {
    Self.remoteMethodCtx('getChanges', {
        description: 'Get changues in the sales of a ticket',
        accessType: 'READ',
        accepts: [{
            arg: 'id',
            type: 'number',
            required: true,
            description: 'the ticket id',
            http: {source: 'path'}
        }],
        returns: {
            type: 'object',
            root: true
        },
        http: {
            path: `/:id/getChanges`,
            verb: 'get'
        }
    });

    Self.getChanges = async(ctx, id, options) => {
        const models = Self.app.models;
        const myOptions = {};
        const $t = ctx.req.__; // $translate

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

        const ticketLogs = await models.TicketLog.find(
            {
                where: {
                    or: [
                        {
                            and: [
                                {originFk: id},
                                {action: 'update'},
                                {changedModel: 'Sale'}
                            ]
                        },
                        {
                            and: [
                                {originFk: id},
                                {action: 'delete'},
                                {changedModel: 'Sale'}
                            ]
                        }
                    ]
                },
                fields: [
                    'oldInstance',
                    'newInstance',
                    'changedModelId',
                    'changedModelValue'
                ],
            }, myOptions);

        const changes = [];

        for (const log of ticketLogs) {
            const oldQuantity = log.oldInstance.quantity;
            const newQuantity = log.newInstance?.quantity || 0;

            if (oldQuantity || newQuantity) {
              const changeMessage = $t('Change quantity', {
                concept: log.changedModelValue,
                oldQuantity: oldQuantity || 0,
                newQuantity: newQuantity || 0,
              });
              changes.push(changeMessage);
            }
          }

        return changes.join('\n');
    };
};