import {OnDestroy} from "@angular/core";
import {Subscription} from "rxjs/Rx";

export class SubscriptionsRemovingComponent implements OnDestroy{
    private subscriptions: Subscription[] = [];

    ngOnDestroy():void {
        this.clearSubscriptions();
    }

    public clearSubscriptions() {
        this.subscriptions.forEach((subscription: Subscription) => {
            subscription.unsubscribe();
        });
    }

    public addSubscription(subscription: Subscription) {
        this.subscriptions.push(subscription);
    }
}

class SelectableGroupList extends SubscriptionsRemovingComponent implements OnDestroy {
    private groups:Group[] = [];
    private searchResults: Group[] = [];

    @Output() groupsSelected: EventEmitter<Group[]> = new EventEmitter<Group[]>();
    @Output() backAction = new EventEmitter<any>();
    @Input() selectedGroups: Array<Group> = [];

    constructor(private groupsService: GroupsService,
                private searchService: SearchService) {
        super();
        this.groupsService.getGroups();
        this.setSubscriptions();
    }

    private setSubscriptions() {
        super.addSubscription(
            this.groupsService.selectedGroupsChanged
                .subscribe((selectedGroups:Group[]) => {
                    this.groupsSelected.emit(selectedGroups);
                    super.clearSubscriptions();
                })
        );

        super.addSubscription(
            this.groupsService.groupsChanged
                .subscribe((groups:Group[]) => {
                    this.groups = this.excludeSelectedGroups(groups);
                    this.searchResults = this.groups;
                    super.clearSubscriptions();
                })
        );
    }

    ngOnDestroy() {
        super.ngOnDestroy();

        this.groupsService.resetSelectedGroups();
    }
}