var ANI_OPT_FROM = {
    marginLeft: -1000,
    marginRight: 1000,
    opacity: 0
}
var ANI_OPT_DEF = {
    marginLeft: 0,
    marginRight: 0,
    opacity: 1
}
var ANI_OPT_TO = {
    marginLeft: 1000,
    marginRight: -1000,
    opacity: 0
}
var SLIDE_SPEED = 'slow';
function slide(n, forward) {
    if (!$('#intro_news_item_'+n).hasClass('selected') && !$('#intro_news_item_old').length ) {
        $('#intro_news_item').before('<div id="intro_news_item_old">'+$('#intro_news_item').html()+'</div>');
        
        var fr = forward ? ANI_OPT_FROM : ANI_OPT_TO;
        var to = forward ? ANI_OPT_TO : ANI_OPT_FROM;

        $('#intro_news_item').html($('#intro_news_item_'+n).html()).find('a').css(fr);
        $('#intro_news_item_old a').animate(to, SLIDE_SPEED, 'easeOutExpo', function() {$(this.parentNode).remove()});
        $('#intro_news_item a').animate(ANI_OPT_DEF, SLIDE_SPEED, 'easeOutExpo');
    
        $('#intro_news div.selected').removeClass('selected');
        $('#intro_news_item_'+n).addClass('selected');
    }
}

function next_slide() {
    $('#intro_news div.source').each(function (n) {
        if ($(this).hasClass('selected')) {
            var next_n = n + 2;
            if (next_n > $('#intro_news div.source').length)
                next_n = 1;
            slide(next_n, true);
            return false;
        }
        return true;
    });
}

function prev_slide() {
    $('#intro_news div.source').each(function (n) {
        if ($(this).hasClass('selected')) {
            var prev_n = n;
            if (prev_n < 1)
                prev_n = $('#intro_news div.source').length;
            slide(prev_n, false);
            return false;
        }
        return true;
    });
}

function animate_background(obj) {
    $(obj).animate({opacity: Math.random()}, 1500, function () {animate_background(obj)})
}
$(function() {
    timer = setInterval(next_slide, 10000);
    $('#intro_news').click(function() {clearInterval(timer)});
    $('#news_right').click(next_slide);
    $('#news_left').click(prev_slide);
    
    $('#header div.bg_ani').each(function() {
        animate_background(this);
    })
});