$(document).ready(function() {
  
  // Einstellungen
  var currentPanel = 1;
  var slideDuration = 5000;
  var panelCount = 3;
  var slideshowTimer;
  
  // Initialisieren
  $(function() {
    $('#navigation-topthema-item-' + currentPanel).addClass('active');
    
    // Panels mit Links versehen
    $("#block-topthema a.link").each(function(i) {
      var link = this;
      var selector = '#panel-topthema-' + (i + 1);
      $(
        selector + ' .image, ' +
        selector + ' .text h3, ' +
        selector + ' .text p, '
      ).click(function() {
        window.location = link;
      });
    });
  });
  
  // Topthema-Navigation überwachen
  $('.navigation-topthema-item').click(function() {
    var itemNumber = this.id.substring(25);
    fadePanel(itemNumber);
    disableTimer();
    return false;
  });

  // Funktion zum Überblenden
  var fadePanel = function(id) {
    if(id != currentPanel) {
      // Folgendes Panel aktivieren
      $('#panel-topthema-' + id).css({
        'z-index' : 1,
        'display' : 'block'
      });
      
      // Aktuelles Panel ausblenden
      $('#panel-topthema-' + currentPanel).fadeOut('slow', function() {
        $('#panel-topthema-' + id).css('z-index', 2);
      });
      
      // Navigation anpassen
      $('#navigation-topthema-item-' + currentPanel).removeClass('active');
      $('#navigation-topthema-item-' + id).addClass('active');
    
      currentPanel = id;
    }
  };
  
  var disableTimer = function() {
    clearInterval(slideshowTimer);
  };
  
  // Slideshow Timer
  $(function() {
    slideshowTimer = setInterval(function() {
      if(currentPanel == panelCount) {
        fadePanel(1);
      } else {
        fadePanel(currentPanel + 1);
      }
    }, slideDuration);
  });
  
});