(function (root, factory) {
    if (typeof define === 'function' && define.amd) {
        // AMD. Register as an anonymous module.
        define([], factory);
    } else {
        // Browser globals
        root.LoadingIndicator = factory();
    }

//============================================================================
}(this, function () {
    //TODO: too specific to history panel
    function LoadingIndicator( $where, options ){

        var self = this;
        // defaults
        options = jQuery.extend({
            cover       : false
        }, options || {} );

        function render(){
            var html = [
                '<div class="loading-indicator">',
                    '<div class="loading-indicator-text">',
                        '<span class="fa fa-spinner fa-spin fa-lg"></span>',
                        '<span class="loading-indicator-message">loading...</span>',
                    '</div>',
                '</div>'
            ].join( '\n' );

            var $indicator = $( html ).hide().css( options.css || {
                    position    : 'fixed'
                }),
                $text = $indicator.children( '.loading-indicator-text' );

            if( options.cover ){
                $indicator.css({
                    'z-index'   : 2,
                    top         : $where.css( 'top' ),
                    bottom      : $where.css( 'bottom' ),
                    left        : $where.css( 'left' ),
                    right       : $where.css( 'right' ),
                    opacity     : 0.5,
                    'background-color': 'white',
                    'text-align': 'center'
                });
                $text = $indicator.children( '.loading-indicator-text' ).css({
                    'margin-top'        : '20px'
                });

            } else {
                $text = $indicator.children( '.loading-indicator-text' ).css({
                    margin              : '12px 0px 0px 10px',
                    opacity             : '0.85',
                    color               : 'grey'
                });
                $text.children( '.loading-indicator-message' ).css({
                    margin          : '0px 8px 0px 0px',
                    'font-style'    : 'italic'
                });
            }
            return $indicator;
        }

        self.show = function( msg, speed, callback ){
            msg = msg || 'loading...';
            speed = speed || 'fast';
            // remove previous
            $where.parent().find( '.loading-indicator' ).remove();
            // since position is fixed - we insert as sibling
            self.$indicator = render().insertBefore( $where );
            self.message( msg );
            self.$indicator.fadeIn( speed, callback );
            return self;
        };

        self.message = function( msg ){
            self.$indicator.find( 'i' ).text( msg );
        };

        self.hide = function( speed, callback ){
            speed = speed || 'fast';
            if( self.$indicator && self.$indicator.size() ){
                self.$indicator.fadeOut( speed, function(){
                    self.$indicator.remove();
                    if( callback ){ callback(); }
                });
            } else {
                if( callback ){ callback(); }
            }
            return self;
        };
        return self;
    }

//============================================================================
    return LoadingIndicator;
}));