/*
* Author:      Marco Kuiper (http://www.marcofolio.net/)
*/

// Speed of the automatic slideshow
var slideshowSpeed = 6000;

// Variable to store the images we need to set as background
// which also includes some text and url's.



$(document).ready(function() {
    
  // Backwards navigation
  $("#back").click(function() {
    stopAnimation();
    navigate("back");
  });
  
  // Forward navigation
  $("#next").click(function() {
    stopAnimation();
    navigate("next");
  });
  
  var interval;
  $("#control").toggle(function(){
    stopAnimation();
  }, function() {
    // Change the background image to "pause"
    $(this).css({ "background-image" : "url(images/btn_pause.png)" });
    
    // Show the next image
    navigate("next");
    
    // Start playing the animation
    interval = setInterval(function() {
      navigate("next");
    }, slideshowSpeed);
  });
  
  
  var activeContainer = 1;  
  var currentImg = 0;
  var animating = false;
  var navigate = function(direction) {
    // Check if no animation is running. If it is, prevent the action
    if(animating) {
      return;
    }
    
    // Check which current image we need to show
    if(direction == "next") {
      currentImg++;
      if(currentImg == photos.length + 1) {
        currentImg = 1;
      }
    } else {
      currentImg--;
      if(currentImg == 0) {
        currentImg = photos.length;
      }
    }
    
    // Check which container we need to use
    var currentContainer = activeContainer;
    if(activeContainer == 1) {
      activeContainer = 2;
    } else {
      activeContainer = 1;
    }
    
    showImage(photos[currentImg - 1], currentContainer, activeContainer);
    
  };
  
  var currentZindex = -1;
  var showImage = function(photoObject, currentContainer, activeContainer) {
    animating = true;
    
    // Make sure the new container is always on the background
    currentZindex--;
    
    // Set the background image of the new active container
    $("#headerimg" + activeContainer).css({
      "background-image" : "url(" + photoObject.image + ")",
      "display" : "block",
      "z-index" : currentZindex
    });
    
    // Hide the header text
    $("#headertxt").css({"display" : "none"});
    
    // Set the new header text
     
    
    // Fade out the current container
    // and display the header text when animation is complete
    $("#headerimg" + currentContainer).fadeOut(function() {
      setTimeout(function() {
        $("#headertxt").css({"display" : "block"});
        animating = false;
      }, 2500);
    });
  };
  
  var stopAnimation = function() {
    // Change the background image to "play"
    $("#control").css({ "background-image" : "url(images/btn_play.png)" });
    
    // Clear the interval
    clearInterval(interval);
  };
  
  // We should statically set the first image
  navigate("next");
  
  // Start playing the animation
  interval = setInterval(function() {
    navigate("next");
  }, slideshowSpeed);
  
});