/**
 * ContentEditable MediaWiki Tabber node.
 *
 * @class
 * @extends ve.ce.MWBlockExtensionNode
 *
 * @constructor
 * @param {ve.dm.MWTabberNode} model Model to observe
 * @param {Object} [config] Configuration options
 */
ve.ce.MWTabberNode = function VeCeMWTabberNode() {
	// Parent constructor
	ve.ce.MWTabberNode.super.apply( this, arguments );

    this.renderHeader = OO.ui.debounce( this.renderHeader.bind( this ), 300 );

	// DOM changes
	this.$element.addClass( 've-ce-mwTabberNode' );
};

/* Inheritance */

OO.inheritClass( ve.ce.MWTabberNode, ve.ce.MWBlockExtensionNode );

/* Static Properties */

ve.ce.MWTabberNode.static.name = 'mwTabber';

ve.ce.MWTabberNode.static.tagName = 'div';

ve.ce.MWTabberNode.static.primaryCommandName = 'mwTabber';

/* Methods */

var lastHeader;

/**
 * @inheritdoc
 */
ve.ce.MWTabberNode.prototype.onSetup = function () {
    // Parent method
    ve.ce.MWTabberNode.super.prototype.onSetup.call( this );

    var tabber = this.$element[ 0 ];

    // Do not render header if it is already rendered
    if ( 
        tabber.firstElementChild &&
        tabber.firstElementChild !== lastHeader &&
        !tabber.classList.contains( 'tabber--live' ) &&
        tabber.classList.contains( 'tabber' ) 
    ) 
    {
        this.renderHeader( tabber );
    }
};

/**
 * HACK: Render a simple static tab header for preview
 * 
 * Since it is only for preview it does not have to be fancy,
 * just having the right HTML and CSS will be sufficient
 * 
 * @param {Object} Tabber HTMLElement
 */
ve.ce.MWTabberNode.prototype.renderHeader = function ( tabber ) {
    var tabPanels = tabber.querySelectorAll( ':scope > .tabber__section > .tabber__panel' ),
        container = document.createElement( 'header' ),
        tabList = document.createElement( 'nav' )
        fragment = new DocumentFragment();

    Array.prototype.forEach.call( tabPanels, function( tabPanel, index ) {
        var tab = document.createElement( 'a' );

        tab.innerText = tabPanel.title;
        tab.classList.add( 'tabber__tab' );

        // Make first tab active
        if ( index === 0 ) {
            tab.classList.add( 'tabber__tab--active' );
        }

        fragment.append( tab );
    } );

    tabList.append( fragment );

    container.classList.add( 'tabber__header' );
    tabList.classList.add( 'tabber__tabs' );

    container.append( tabList );
    tabber.prepend( container );

    tabber.classList.add( 'tabber--live' );

    lastHeader = tabber.firstElementChild;
}

/* Registration */

ve.ce.nodeFactory.register( ve.ce.MWTabberNode );