import { Injectable } from '@angular/core';
import { BehaviorSubject, Observable } from 'rxjs';

import { WorkflowStep } from '../enums/workflow-step.enum';

@Injectable({
	providedIn: 'root',
})
export class WorkflowService {
	private steps = [WorkflowStep.DESCRIPTION, WorkflowStep.CHOICES, WorkflowStep.CONFIGURATION];

	private _currentStep: BehaviorSubject<WorkflowStep> = new BehaviorSubject<WorkflowStep>(WorkflowStep[0]);
	public readonly currentStep: Observable<WorkflowStep> = this._currentStep.asObservable();

	constructor() {}

	public loadNextStep(): void {
		this._currentStep.next(WorkflowStep[this.getNewIndex(1)]);
	}

	public loadPriorStep(): void {
		this._currentStep.next(WorkflowStep[this.getNewIndex(-1)]);
	}

	private getNewIndex(way: number): number {
		const currentIndex: number = Object.keys(WorkflowStep).indexOf(this._currentStep.getValue());
		const newIndex: number = currentIndex + way;
		return 0 <= newIndex && newIndex <= Object.keys(WorkflowStep).length ? newIndex : currentIndex;
	}
}