( function () {
	/**
	 * Filters model for displaying filtered notification list.
	 *
	 * @class
	 * @mixes OO.EventEmitter
	 *
	 * @constructor
	 * @param {Object} config Configuration object
	 * @param {string} [config.readState='all'] Notifications read state. Allowed
	 *  values are 'all', 'read' or 'unread'.
	 * @param {string} [config.selectedSource] Currently selected source
	 */
	mw.echo.dm.FiltersModel = function MwEchoDmFiltersModel( config ) {
		config = config || {};

		// Mixin constructor
		OO.EventEmitter.call( this );

		this.readState = config.readState || 'all';

		this.sourcePagesModel = new mw.echo.dm.SourcePagesModel();
		this.selectedSource = config.selectedSource || '';
		this.selectedSourcePage = null;
	};

	/* Initialization */

	OO.initClass( mw.echo.dm.FiltersModel );
	OO.mixinClass( mw.echo.dm.FiltersModel, OO.EventEmitter );

	/* Events */

	/**
	 * The filters have been updated
	 *
	 * @event mw.echo.dm.FiltersModel#update
	 */

	/* Methods */

	/**
	 * Set the read state filter
	 *
	 * @param {string} readState Notifications read state
	 * @fires mw.echo.dm.FiltersModel#update
	 */
	mw.echo.dm.FiltersModel.prototype.setReadState = function ( readState ) {
		const allowed = [ 'all', 'read', 'unread' ];
		if (
			this.readState !== readState &&
			allowed.indexOf( readState ) > -1
		) {
			this.readState = readState;
			this.emit( 'update' );
		}
	};

	/**
	 * Get the read state filter
	 *
	 * @return {string} Notifications read state
	 */
	mw.echo.dm.FiltersModel.prototype.getReadState = function () {
		return this.readState;
	};

	/**
	 * Set the currently selected source and page.
	 * If no page is given, or if page is null, the source title
	 * is assumed to be selected.
	 *
	 * @param {string} source Source name
	 * @param {string} [page] Page name
	 */
	mw.echo.dm.FiltersModel.prototype.setCurrentSourcePage = function ( source, page ) {
		this.sourcePagesModel.setCurrentSourcePage( source, page );
	};

	/**
	 * Get the total count of a source. This sums the count of all
	 * sub pages in that source.
	 *
	 * @param {string} source Symbolic name for source
	 * @return {number} Total count
	 */
	mw.echo.dm.FiltersModel.prototype.getSourceTotalCount = function ( source ) {
		return this.sourcePagesModel.getSourceTotalCount( source );
	};

	/**
	 * Get the source page model
	 *
	 * @return {mw.echo.dm.SourcePagesModel} Source pages model
	 */
	mw.echo.dm.FiltersModel.prototype.getSourcePagesModel = function () {
		return this.sourcePagesModel;
	};

}() );