/**
 * ButtonWidget is a generic widget for buttons. A wide variety of looks,
 * feels, and functionality can be customized via the class’s configuration options
 * and methods. Please see the [OOjs UI documentation on MediaWiki] [1] for more information
 * and examples.
 *
 * [1]: https://www.mediawiki.org/wiki/OOjs_UI/Widgets/Buttons_and_Switches
 *
 *     @example
 *     // A button widget
 *     var button = new OO.ui.ButtonWidget( {
 *         label: 'Button with Icon',
 *         icon: 'remove',
 *         iconTitle: 'Remove'
 *     } );
 *     $( 'body' ).append( button.$element );
 *
 * NOTE: HTML form buttons should use the OO.ui.ButtonInputWidget class.
 *
 * @class
 * @extends OO.ui.Widget
 * @mixins OO.ui.ButtonElement
 * @mixins OO.ui.IconElement
 * @mixins OO.ui.IndicatorElement
 * @mixins OO.ui.LabelElement
 * @mixins OO.ui.TitledElement
 * @mixins OO.ui.FlaggedElement
 * @mixins OO.ui.TabIndexedElement
 *
 * @constructor
 * @param {Object} [config] Configuration options
 * @cfg {string} [href] Hyperlink to visit when the button is clicked.
 * @cfg {string} [target] The frame or window in which to open the hyperlink.
 * @cfg {boolean} [noFollow] Search engine traversal hint (default: true)
 */
OO.ui.ButtonWidget = function OoUiButtonWidget( config ) {
	// Configuration initialization
	config = config || {};

	// Parent constructor
	OO.ui.ButtonWidget.super.call( this, config );

	// Mixin constructors
	OO.ui.ButtonElement.call( this, config );
	OO.ui.IconElement.call( this, config );
	OO.ui.IndicatorElement.call( this, config );
	OO.ui.LabelElement.call( this, config );
	OO.ui.TitledElement.call( this, $.extend( {}, config, { $titled: this.$button } ) );
	OO.ui.FlaggedElement.call( this, config );
	OO.ui.TabIndexedElement.call( this, $.extend( {}, config, { $tabIndexed: this.$button } ) );

	// Properties
	this.href = null;
	this.target = null;
	this.noFollow = false;

	// Events
	this.connect( this, { disable: 'onDisable' } );

	// Initialization
	this.$button.append( this.$icon, this.$label, this.$indicator );
	this.$element
		.addClass( 'oo-ui-buttonWidget' )
		.append( this.$button );
	this.setHref( config.href );
	this.setTarget( config.target );
	this.setNoFollow( config.noFollow );
};

/* Setup */

OO.inheritClass( OO.ui.ButtonWidget, OO.ui.Widget );
OO.mixinClass( OO.ui.ButtonWidget, OO.ui.ButtonElement );
OO.mixinClass( OO.ui.ButtonWidget, OO.ui.IconElement );
OO.mixinClass( OO.ui.ButtonWidget, OO.ui.IndicatorElement );
OO.mixinClass( OO.ui.ButtonWidget, OO.ui.LabelElement );
OO.mixinClass( OO.ui.ButtonWidget, OO.ui.TitledElement );
OO.mixinClass( OO.ui.ButtonWidget, OO.ui.FlaggedElement );
OO.mixinClass( OO.ui.ButtonWidget, OO.ui.TabIndexedElement );

/* Methods */

/**
 * @inheritdoc
 */
OO.ui.ButtonWidget.prototype.onMouseDown = function ( e ) {
	if ( !this.isDisabled() ) {
		// Remove the tab-index while the button is down to prevent the button from stealing focus
		this.$button.removeAttr( 'tabindex' );
	}

	return OO.ui.ButtonElement.prototype.onMouseDown.call( this, e );
};

/**
 * @inheritdoc
 */
OO.ui.ButtonWidget.prototype.onMouseUp = function ( e ) {
	if ( !this.isDisabled() ) {
		// Restore the tab-index after the button is up to restore the button's accessibility
		this.$button.attr( 'tabindex', this.tabIndex );
	}

	return OO.ui.ButtonElement.prototype.onMouseUp.call( this, e );
};

/**
 * Get hyperlink location.
 *
 * @return {string} Hyperlink location
 */
OO.ui.ButtonWidget.prototype.getHref = function () {
	return this.href;
};

/**
 * Get hyperlink target.
 *
 * @return {string} Hyperlink target
 */
OO.ui.ButtonWidget.prototype.getTarget = function () {
	return this.target;
};

/**
 * Get search engine traversal hint.
 *
 * @return {boolean} Whether search engines should avoid traversing this hyperlink
 */
OO.ui.ButtonWidget.prototype.getNoFollow = function () {
	return this.noFollow;
};

/**
 * Set hyperlink location.
 *
 * @param {string|null} href Hyperlink location, null to remove
 */
OO.ui.ButtonWidget.prototype.setHref = function ( href ) {
	href = typeof href === 'string' ? href : null;

	if ( href !== this.href ) {
		this.href = href;
		this.updateHref();
	}

	return this;
};

/**
 * Update the `href` attribute, in case of changes to href or
 * disabled state.
 *
 * @private
 * @chainable
 */
OO.ui.ButtonWidget.prototype.updateHref = function () {
	if ( this.href !== null && !this.isDisabled() ) {
		this.$button.attr( 'href', this.href );
	} else {
		this.$button.removeAttr( 'href' );
	}

	return this;
};

/**
 * Handle disable events.
 *
 * @private
 * @param {boolean} disabled Element is disabled
 */
OO.ui.ButtonWidget.prototype.onDisable = function () {
	this.updateHref();
};

/**
 * Set hyperlink target.
 *
 * @param {string|null} target Hyperlink target, null to remove
 */
OO.ui.ButtonWidget.prototype.setTarget = function ( target ) {
	target = typeof target === 'string' ? target : null;

	if ( target !== this.target ) {
		this.target = target;
		if ( target !== null ) {
			this.$button.attr( 'target', target );
		} else {
			this.$button.removeAttr( 'target' );
		}
	}

	return this;
};

/**
 * Set search engine traversal hint.
 *
 * @param {boolean} noFollow True if search engines should avoid traversing this hyperlink
 */
OO.ui.ButtonWidget.prototype.setNoFollow = function ( noFollow ) {
	noFollow = typeof noFollow === 'boolean' ? noFollow : true;

	if ( noFollow !== this.noFollow ) {
		this.noFollow = noFollow;
		if ( noFollow ) {
			this.$button.attr( 'rel', 'nofollow' );
		} else {
			this.$button.removeAttr( 'rel' );
		}
	}

	return this;
};