import {
    Injector,
    TemplateRef,
    ViewRef,
    ViewContainerRef,
    Renderer,
    ComponentRef,
    ComponentFactory,
    ComponentFactoryResolver
} from '@angular/core';

export class ContentRef {
    constructor(public nodes: any[], public viewRef?: ViewRef, public componentRef?: ComponentRef<any>) {}
}

export class PopupService<T> {
    private _windowFactory: ComponentFactory<T>;
    private _windowRef: ComponentRef<T>;
    private _contentRef: ContentRef;

    constructor(
        type: any, private _injector: Injector, private _viewContainerRef: ViewContainerRef, private _renderer: Renderer,
        componentFactoryResolver: ComponentFactoryResolver) {
        this._windowFactory = componentFactoryResolver.resolveComponentFactory<T>(type);
    }

    open(content?: string | TemplateRef<any>, context?: any): ComponentRef<T> {
        if (!this._windowRef) {
            this._contentRef = this._getContentRef(content, context);
            this._windowRef =
                this._viewContainerRef.createComponent(this._windowFactory, 0, this._injector, this._contentRef.nodes);
        }

        return this._windowRef;
    }

    close() {
        if (this._windowRef) {
            this._viewContainerRef.remove(this._viewContainerRef.indexOf(this._windowRef.hostView));
            this._windowRef = null;

            if (this._contentRef.viewRef) {
                this._viewContainerRef.remove(this._viewContainerRef.indexOf(this._contentRef.viewRef));
                this._contentRef = null;
            }
        }
    }

    private _getContentRef(content: string | TemplateRef<any>, context?: any): ContentRef {
        if (!content) {
            return new ContentRef([]);
        } else if (content instanceof TemplateRef) {
            const viewRef = this._viewContainerRef.createEmbeddedView(<TemplateRef<T>>content, context);
            return new ContentRef([viewRef.rootNodes], viewRef);
        } else {
            return new ContentRef([[this._renderer.createText(null, `${content}`)]]);
        }
    }
}