import {Injectable} from '@angular/core';
import {Observable} from 'rxjs/Observable';
import {Subject} from 'rxjs/Subject';
import {ErrorMessage} from '../objects/error-message';

@Injectable()
export class MessageService {
    private subjects: { [forId: string]: Subject<ErrorMessage>; } = {};
    private observables: { [forId: string]: Observable<ErrorMessage>; } = {};

    constructor() {
    }

    /**
     * h messages subscribe here to listen for new errors
     * @param {string} forId
     * @param {(value: ErrorMessage) => void} [next]
     * @param {(error: any) => void} [error]
     * @returns {Subscription}
     */
    subscribe(forId: string, next?: (value: ErrorMessage) => void,
              error?: (error: any) => void) {
        // check if there is an entry for this id
        if (!this.subjects.hasOwnProperty(forId)) {
            this.subjects[forId] = new Subject<ErrorMessage>();
            this.observables[forId] = this.subjects[forId].asObservable();
        }

        return this.observables[forId].subscribe(next, error);
    }

    /**
     * jsf inputs send their validation result here
     * @param {string} id
     * @param {boolean} hasError
     * @param {string} [message]
     */
    submitError(id: string, hasError: boolean, message?: string) {
        // make sure there is an observable for this input
        if (!this.subjects.hasOwnProperty(id)) {
            this.subjects[id] = new Subject<ErrorMessage>();
            this.observables[id] = this.subjects[id].asObservable();
        }

        // now notify the observable about the error message
        this.subjects[id].next(new ErrorMessage(hasError, message));
    }
}