/*--------------------------------------------------------------------------------------------------------------
 *  Copyright (c) insite-gmbh. All rights reserved.
 *  Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 *--------------------------------------------------------------------------------------------------------------*/
import { Component, OnInit, OnDestroy, Input, Output, EventEmitter, Inject } from '@angular/core';
import { ActivatedRoute } from '@angular/router';
import { Subscription } from 'rxjs/Rx';
import { IMENUPROVIDERSERVICE_TOKEN, IMenuProvider } from '../../../menu/src/interfaces/menuProvider';
import { IMenuItem } from '../../../menu/src/interfaces/menuItem';
import { DefaultMenuItem } from '../../../menu/src/default/defaultMenuItem';
import { EmptyMenuItem } from '../../../menu/src/default/emptyMenuItem';


@Component({
    selector: 'button-menu',
    templateUrl: './@inax/buttonMenuUi/src/buttonMenu/buttonMenu.component.html',
    styleUrls: ['./@inax/buttonMenuUi/src/buttonMenu/buttonMenu.component.css']
})
/**
 * Base component for the ButtonMenu
 * @class ButtonMenuComponent
 * @classdesc Base component for the ButtonMenu
 * @author insite-gmbh
 */
export class ButtonMenuComponent implements OnInit, OnDestroy {
    private _subscription: Subscription;
    private _submenuSubscription: Subscription;

    public lines:Array<Array<IMenuItem>> = [];

    public get numberOfLines():number{
        return this.lines != null ? this.lines.length : 0;
    } 

    /**
     * constructor.
     * @param {IMenuProvider} _menuProvider The menu provider is the service for the button menu, it is used to get the menu and
     * also to invoke the commands.
    */
    constructor(@Inject(IMENUPROVIDERSERVICE_TOKEN) private _menuProvider: IMenuProvider) { }

    /**
     * This method will be called when the component is initializing
     * @method ngOnInit
     */
    public ngOnInit() {
        this._subscription = this._menuProvider.subscribeToEntriesFor(null).subscribe(result => 
        {
            this.lines = []; //Empty the array
            this.lines.push(this.createEmptyMenu(result));
            this.lines.push(result);
        });
    }

    /**
     * This method will be called when the component was destroyed
     * @method ngOnDestroy
     */
    public ngOnDestroy() {
        if(this._subscription != null)
            this._subscription.unsubscribe();
        if(this._submenuSubscription != null)
            this._submenuSubscription.unsubscribe();
    }

    /**
     * This method will we called from the menu line to notify the menu when a selection was changed.
     * @method onSelected
     * @param {IMenuItem} parent Current selected parent menu item.
     */
    public onSelected(parent:IMenuItem){
        if(this._submenuSubscription != null)
            this._submenuSubscription.unsubscribe();
        this._submenuSubscription = this._menuProvider.subscribeToEntriesFor(parent).subscribe(result => 
        {
            this.lines = this.lines.reverse();
            this.lines.pop();
            this.lines.push(result);
            this.lines = this.lines.reverse();
        });
    }

    /**
     * This methods will get called if no main menu was selected, so it will generate a dummy submenu line.
     * @method registerEvents
     * @param {Array<IMenuItem>} mainLine The main menu
     */
    private createEmptyMenu(mainLine:Array<IMenuItem>):Array<IMenuItem>{
        let result = new Array<IMenuItem>();
        if(mainLine != null && mainLine.length > 0){
            let first = mainLine[0];
            for(let i = 0; i < mainLine.length; i++){
                result[i] = new EmptyMenuItem(i,first);
            }
        }
        return  result;
    }

}