import { Injectable } from '@angular/core';
import { Action, Store } from '@tethys/store';
import { of } from 'rxjs';
import { tap } from 'rxjs/operators';

interface CounterState {
    count: number;
}

@Injectable()
export class CounterStore extends Store<CounterState> {
    static countSelector(state: CounterState) {
        return state.count;
    }

    constructor() {
        super({ count: 0 });
    }

    @Action()
    increase() {
        return of(true).pipe(
            tap(() => {
                this.update({ count: this.snapshot.count + 1 });
            })
        );
    }

    @Action()
    decrease() {
        return of(true).pipe(
            tap(() => {
                this.update((state) => {
                    return {
                        count: state.count - 1
                    };
                });
            })
        );
    }
}

@Component({
    selector: 'thy-store-counter-example',
    template: `<div>Count: {{ count$ | async }}</div>
               <button class="dg-btn dg-btn-primary dg-btn-sm" (click)="increase()">+</button>
               <button class="dg-btn dg-btn-primary dg-btn-sm" (click)="decrease()">-</button>
`,
    styleUrls: ['./counter.component.scss']
})
export class ThyStoreCounterExampleComponent implements OnInit {
    count$: Observable<number> = this.counterStore.select$(CounterStore.countSelector);

    constructor(public counterStore: CounterStore) {}

    ngOnInit(): void {}

    increase() {
        this.counterStore.increase();
    }

    decrease() {
        this.counterStore.decrease();
    }
}