import Service from '@ember/service';
import { getOwner } from '@ember/application';

export default Service.extend({
    states: [],
    max: 16,
    previous() {
        return this.get('states.lastObject');
    },
    push(url) {
        if (url) {
            const me = this;
            me.get('states').pushObject(url);
            while (me.get('states.length') > me.get('max')) {
                me.get('states').shiftObject();
            }
        }
    },
    back() {
        const me = this;
        const url = me.previous();
        if (url) {
            const router = getOwner(this).lookup('router:main');
            router.transitionTo(url);
        }
        return url;
    }
});