import { Component, ViewChild, AfterViewInit, ElementRef } from '@angular/core';
import { Http } from '@angular/http';
import { map } from "rxjs/operators";
import { jqxExpanderComponent } from 'jqwidgets-scripts/jqwidgets-ts/angular_jqxexpander';
import { jqxTreeComponent } from 'jqwidgets-scripts/jqwidgets-ts/angular_jqxtree';
import { jqxPanelComponent } from 'jqwidgets-scripts/jqwidgets-ts/angular_jqxpanel';
import { jqxListBoxComponent } from 'jqwidgets-scripts/jqwidgets-ts/angular_jqxlistbox';

@Component({
    selector: 'app-root',
    templateUrl: './app.component.html'
})

export class AppComponent implements AfterViewInit {
    @ViewChild('feedContentExpander') feedContentExpander: jqxExpanderComponent;
    @ViewChild('feedListExpander') feedListExpander: jqxExpanderComponent;
    @ViewChild('listBoxReference') myListBox: jqxListBoxComponent;
    @ViewChild('panelReference') myPanel: jqxPanelComponent;
    @ViewChild('treeReference') myTree: jqxTreeComponent;
   	getWidth() : any {
		if (document.body.offsetWidth < 850) {
			return '90%';
		}
		
		return 850;
	} 
    constructor(public http: Http) { }
    ngAfterViewInit(): void {
        this.getFeed('sciencedaily');
    }

    onTreeSelect(event: any): void {
        let item = this.myTree.getItem(event.args.element);
        this.getFeed(this.config['feeds'][item.label]);
    };

    onListBoxSelect(event: any): void {
        this.loadContent(event.args.index);
    };

    selectFirst(): void {
        this.myListBox.selectIndex(0);
        this.loadContent(0);
    };

    getFeed(feed: any): void {
        this.config['currentFeed'] = feed;
        if (feed !== undefined) {
            feed = this.config['dataDir'] + '/' + feed + '.' + this.config['format'];
            this.loadFeed(feed);
        }
    };

    loadFeed(feed: any, callback?: any): void {
        let response;
        this.http.get(feed)
            .pipe(map(res => res.json()))
            .subscribe(
            data => response = data,
            err => console.log(err),
            () => {
                let channel = response.rss.channel;
                this.config['currentFeedContent'] = channel.item;
                this.displayFeedList(this.config['currentFeedContent']);
                this.displayFeedHeader(channel.title);
                this.selectFirst();
            }
            );
    };

    displayFeedHeader(header: string): void {
        this.feedListExpander.setHeaderContent(header);
    };

    displayFeedList(items: any): void {
        let headers = this.getHeaders(items);
        this.myListBox.source(headers);
    };

    getHeaders(items: any): any {
        let headers = [], header;
        for (let i = 0; i < items.length; i += 1) {
            header = items[i].title;
            headers.push(header);
        }
        return headers
    };

    loadContent(index: number): void {
        let item = this.config['currentFeedContent'][index];
        if (item != null) {
            this.myPanel.clearcontent();
            this.myPanel.prepend('<div style="padding: 1px;"><span>' + item.description + '</span></div>');
            this.addContentHeaderData(item);
            this.config['selectedIndex'] = index;
        }
    };

    addContentHeaderData(item: any): void {
        let link = document.createElement('a');
        link.style.whiteSpace = 'nowrap';
        link.style.marginLeft = '15px';
        link.target = '_blank';
        let text = document.createTextNode('Source');
        link.appendChild(text);
        let date = document.createElement('div');
        date.style.whiteSpace = 'nowrap';
        date.style.marginLeft = '30px';
        date.appendChild(document.createTextNode(item.pubDate));
        let container = (<HTMLElement>document.createElement('table'));
        container.style.height = '100%';
        let element1 = (<HTMLElement>document.createElement('tr'));
        container.appendChild(element1);
        container.appendChild(document.createElement('td'));
        container.appendChild(document.createElement('td'));
        link.href = item.link;
        (<HTMLElement>document.getElementById('feedItemHeader')).innerHTML = null;
        (<HTMLElement>document.getElementById('feedItemHeader')).appendChild(container);
        container.getElementsByTagName('td')[0].appendChild(link);
        container.querySelector('td:last-child').appendChild(date);
        this.feedContentExpander.setHeaderContent(container.outerHTML);
    };

    config: any =
    {
        feeds: { 'CNN.com': 'cnn', 'Geek.com': 'geek', 'ScienceDaily': 'sciencedaily' },
        format: 'txt',
        dataDir: '../assets',
        feedTree: (<HTMLElement>document.getElementsByTagName('angularTree')[0]),
        feedItemHeader: (<HTMLElement>document.getElementById('feedItemHeader')),
        feedUpperPanel: (<HTMLElement>document.getElementById('feedUpperPanel')),
        feedHeader: (<HTMLElement>document.getElementById('feedHeader')),
        feedContentArea: (<HTMLElement>document.getElementById('feedContentArea')),
        selectedIndex: -1,
        currentFeed: '',
        currentFeedContent: {}
    };
}