( function ( mw ) {
	/**
	 * Button for marking all changes as seen on the Watchlist
	 *
	 * @extends OO.ui.ButtonWidget
	 *
	 * @constructor
	 * @param {mw.rcfilters.Controller} controller
	 * @param {mw.rcfilters.dm.ChangesListViewModel} model Changes list view model
	 * @param {Object} [config] Configuration object
	 */
	mw.rcfilters.ui.MarkSeenButtonWidget = function MwRcfiltersUiMarkSeenButtonWidget( controller, model, config ) {
		config = config || {};

		// Parent
		mw.rcfilters.ui.MarkSeenButtonWidget.parent.call( this, $.extend( {
			label: mw.message( 'rcfilters-watchlist-markseen-button' ).text(),
			icon: 'checkAll'
		}, config ) );

		this.controller = controller;
		this.model = model;

		// Events
		this.connect( this, { click: 'onClick' } );
		this.model.connect( this, { update: 'onModelUpdate' } );

		this.$element.addClass( 'mw-rcfilters-ui-markSeenButtonWidget' );

		this.onModelUpdate();
	};

	/* Initialization */

	OO.inheritClass( mw.rcfilters.ui.MarkSeenButtonWidget, OO.ui.ButtonWidget );

	/* Methods */

	/**
	 * Respond to the button being clicked
	 */
	mw.rcfilters.ui.MarkSeenButtonWidget.prototype.onClick = function () {
		this.controller.markAllChangesAsSeen();
		// assume there's no more unseen changes until the next model update
		this.setDisabled( true );
	};

	/**
	 * Respond to the model being updated with new changes
	 */
	mw.rcfilters.ui.MarkSeenButtonWidget.prototype.onModelUpdate = function () {
		this.setDisabled( !this.model.hasUnseenWatchedChanges() );
	};

}( mediaWiki ) );