import { Injectable } from "@angular/core";
import { Subject } from 'rxjs/Subject';
import { Observable } from 'rxjs/Observable';

export const light: string = "light";
export const dark: string = "dark";

@Injectable()
export class CmThemeService {
    public defaultTheme: string;
    private _currentTheme: string;
    private themeSource = new Subject<string>();
    public missionTheme$: Observable<string>;
    constructor() {
        this.missionTheme$ = this.themeSource.asObservable();
        this.defaultTheme = light;
    }
    public get currentTheme(): string {
        return this._currentTheme;
    }
    public use(themeName: string): void {
        document.documentElement.setAttribute('class', "theme-" + themeName);
        this._currentTheme = themeName;
        this.themeSource.next(themeName);
    }
}