import {
    ApplicationRef, ComponentFactoryResolver, ComponentRef, EmbeddedViewRef, Injectable, Injector
} from '@angular/core';

import { PortalInjector } from '../portal/portal-injector';
import { OverlayContainer } from '../overlay/overlay-container';

export interface ComponentType<T> {
    new(...args: any[]): T;
}

@Injectable()
export class DomService {
    constructor(
        private readonly injector: Injector,
        private readonly appRef: ApplicationRef,
        private readonly overlayContainer: OverlayContainer,
        private readonly componentFactoryResolver: ComponentFactoryResolver,
    ) {}

    public attachComponentPortal<T>(component: ComponentType<T>, injector?: PortalInjector): ComponentRef<T> {
        const componentRef: ComponentRef<T> = this.componentFactoryResolver
            .resolveComponentFactory(component)
            .create(injector ? injector : this.injector);

        this.appRef.attachView(componentRef.hostView);

        this.overlayContainer.getContainerElement().appendChild(this.getComponentRootNode(componentRef));

        return componentRef;
    }

    private readonly getComponentRootNode = (componentRef: ComponentRef<any>): HTMLElement => {
        return (componentRef.hostView as EmbeddedViewRef<any>).rootNodes[0] as HTMLElement;
    }
}