/**
 *
 *	FotoFlow 1.0
 *
**/


/* Configuration variables */
var conf_reflection_p = .5;         // Sets the height of the reflection in % of the source image 
var conf_focus = 3;                  // Sets the numbers of images on each side of the focused one
var conf_slider_width = 40;          // Sets the px width of the slider div
var conf_images_cursor = 'pointer';  // Sets the cursor type for all images default is 'default'
var conf_slider_cursor = 'e-resize';  // Sets the slider cursor type: try "e-resize" default is 'default'

/* Id names used in the HTML */
var conf_fotoflow = 'fotoflow';    // Default is 'fotoflow'
var conf_loading = 'preloader';    // Default is 'loading'
var conf_images = 'fotos';          // Default is 'images'
var conf_captions = 'captions';      // Default is 'captions'
var conf_scrollbar = 'scrollbar';    // Default is 'scrollbar'
var conf_slider = 'slider';          // Default is 'slider'

/* Define global variables */
var caption_id = 0;
var new_caption_id = 0;
var current = 0;
var target = 0;
var mem_target = 0;
var timer = 0;
var array_images = new Array();
var new_slider_pos = 0;
var dragging = false;
var dragobject = null;
var dragx = 0;
var posx = 0;
var new_posx = 0;
var xstep = 150;


function step()
{
	switch (target < current-1 || target > current+1) 
	{
		case true:
			moveTo(current + (target-current)/3);
			window.setTimeout(step, 50);
			timer = 1;
			break;

		default:
			timer = 0;
			break;
	}
}

function glideTo(x, new_caption_id)
{	
	/* Animate gliding to new x position */
	target = x;
	mem_target = x;
	if (timer == 0)
	{
		window.setTimeout(step, 50);
		timer = 1;
	}
	
	/* Display new caption */
	caption_id = new_caption_id;
	caption = image_array[caption_id].getAttribute('alt');
	if (caption == '') caption = '&nbsp;';
	caption_div.innerHTML = "<font color=#FFFFFF size=4>" + caption + "</font>";

	/* Set scrollbar slider to new position */
	if (dragging == false)
	{
		new_slider_pos = (scrollbar_width * (-(x*100/((max-1)*xstep))) / 100) - new_posx;
		slider_div.style.marginLeft = (new_slider_pos - conf_slider_width + 20) + 'px';
	}
}

function moveTo(x)
{
	current = x;
	var zIndex = max;
	
	/* Main loop */
	for (var index = 0; index < max; index++)
	{
		var image = image_array[index];
		var current_image = index * -xstep;

		/* Don't display images that are not conf_focused */
		if ((current_image+max_conf_focus) < mem_target || (current_image-max_conf_focus) > mem_target)
		{
			image.style.visibility = 'hidden';
			image.style.display = 'none';
		}
		else 
		{
			var z = Math.sqrt(10000 + x * x) + 100;
			var xs = x / z * size + size;

			/* Still hide images until they are processed, but set display style to block */
			image.style.display = 'block';
		
			/* Process new image height and image width */
			var new_img_h = (image.h / image.w * image.pc) / z * size;
			switch ( new_img_h > max_height )
			{
				case false:
					var new_img_w = image.pc / z * size;
					break;

				default:
					new_img_h = max_height;
					var new_img_w = image.w * new_img_h / image.h;
					break;
			}
			var new_img_top = (images_width * 0.34 - new_img_h) + images_top + ((new_img_h / (conf_reflection_p + 1)) * conf_reflection_p);

			/* Set new image properties */
			image.style.left = xs - (image.pc / 2) / z * size + images_left + 'px';
			if(new_img_w && new_img_h)
			{ 
				image.style.height = new_img_h + 'px'; 
				image.style.width = new_img_w + 'px'; 
				image.style.top = new_img_top + 'px';
			}
			image.style.visibility = 'visible';

			/* Set image layer through zIndex */
			switch ( x < 0 )
			{
				case true:
					zIndex++;
					break;

				default:
					zIndex = zIndex - 1;
					break;
			}
			
			/* Change zIndex and onclick function of the focused image */
			switch ( image.i == caption_id )
			{
				case false:
					image.onclick = function() { glideTo(this.x_pos, this.i); }
					break;

				default:
					zIndex = zIndex + 1;
					if(image.url !== null && image.url !== '')
					{
						image.onclick = function() { document.location = this.url; }
					}
					break;
			}
			image.style.zIndex = zIndex;
		}
		x += xstep;
	}
}

/* Main function */
function refresh(onload)
{
	/* Cache document objects in global variables */
	fotoflow_div = document.getElementById(conf_fotoflow);
	img_div = document.getElementById(conf_images);
	scrollbar_div = document.getElementById(conf_scrollbar);
	slider_div = document.getElementById(conf_slider);
	caption_div = document.getElementById(conf_captions);

	/* Cache global variables, that only change on refresh */
	images_width = img_div.offsetWidth;
	images_top = fotoflow_div.offsetTop;
	images_left = fotoflow_div.offsetLeft;
	max_conf_focus = conf_focus * xstep;
	size = images_width * 0.5;
	scrollbar_width = images_width * 0.6;
	//conf_slider_width = conf_slider_width * 0.5;
	max_height = images_width * 0.51;

	/* Change fotoflow div properties */
	fotoflow_div.style.height = max_height + 'px';

	/* Change images div properties */
	img_div.style.height = images_width * 0.338 + 'px';

	/* Change captions div properties */
	caption_div.style.width = images_width + 'px';
	caption_div.style.marginTop = images_width * .006 + 'px';

	/* Change scrollbar div properties */
	scrollbar_div.style.marginTop = images_width * 0.02 + 'px';
	scrollbar_div.style.marginLeft = images_width * 0.2 + 'px';
	scrollbar_div.style.width = scrollbar_width + 'px';
	
	/* Set slider attributes */
	//slider_div.onmousedown = function () { dragstart(this); };
	slider_div.onmousedown = function () { dragstart(this);return false; };
	slider_div.style.cursor = conf_slider_cursor;


	/* Get only the images */
	image_array = img_div.getElementsByTagName('img');

	/* Cache EVERYTHING! */
	max = image_array.length;
	var i = 0;
	for (var index = 0; index < max; index++)
	{ 
		var image = image_array[index];

		array_images[i] = index;
		
		/* Set image onclick by adding i and x_pos as attributes! */
		image.onclick = function() { glideTo(this.x_pos, this.i); }
		image.x_pos = (-i * xstep);
		image.i = i;

		
		/* Add width and height as attributes ONLY once onload */
		if(onload == true)
		{
			image.w = image.width;
			image.h = image.height;
		}

		/* Check source image format. Get image height minus reflection height! */
		switch ((image.w + 1) > (image.h / (conf_reflection_p + 1))) 
		{
			/* Landscape format */
			case true:
				image.pc = 175;
				break;

			/* Portrait and square format */
			default:
				image.pc = 100;
				break;
		}

		/* Set ondblclick event only if the longdesc attribute is set and not empty */
		image.url = image.getAttribute('lbox');
		if(image.url !== null && image.url !== '')
		{
			image.ondblclick = function() { document.location = this.url; }
		}

		/* Set image cursor type */
		image.style.cursor = conf_images_cursor;

		i++;
	}
	max = array_images.length;

	/* Display images in current order */
	moveTo(current);
	glideTo(current, caption_id);
}

/* Show/hide element functions */
function show(id)
{
	var element = document.getElementById(id);
	element.style.visibility = 'visible';
}
function hide(id)
{
	var element = document.getElementById(id);
	element.style.visibility = 'hidden';
	element.style.display = 'none';
}

/* Hide loading bar, show content and initialize mouse event listening after loading */
window.onload = function()
{
	/* This Allows For Shadow Box To Be Used */Shadowbox.init();/* This Allows For Shadow Box To Be Used */
	if(document.getElementById(conf_fotoflow))
	{
		hide(conf_loading);
		refresh(true);
		show(conf_images);
		show(conf_scrollbar);
		initMouseWheel();
		initMouseDrag();
		glideTo( 0, 0);
	}
}

/* Refresh fotoflow on window resize */
window.onresize = function()
{
	if(document.getElementById(conf_fotoflow)) refresh();
}

/* Fixes the back button issue */
window.onunload = function()
{
  document = null;
}

/* Handle the wheel angle change (delta) of the mouse wheel */
function handle(delta)
{
	var change = false;
	switch (delta > 0)
	{
		case true:
			if(caption_id >= 1)
			{
				target = target + xstep;
				new_caption_id = caption_id - 1;
				change = true;
			}
			break;

		default:
			if(caption_id < (max-1))
			{
				target = target - xstep;
				new_caption_id = caption_id + 1;
				change = true;
			}
			break;
	}

	/* Glide to next (mouse wheel down) / previous (mouse wheel up) image */
	if (change == true)
	{
		glideTo(target, new_caption_id);
	}
}

/* Event handler for mouse wheel event */
function wheel(event)
{
	var delta = 0;
	if (!event) event = window.event;
	if (event.wheelDelta)
	{
		delta = event.wheelDelta / 120;
	}
	else if (event.detail)
	{
		delta = -event.detail / 3;
	}
	if (delta) handle(delta);
	if (event.preventDefault) event.preventDefault();
	event.returnValue = false;
}

/* Initialize mouse wheel event listener */
function initMouseWheel()
{
	if(window.addEventListener) fotoflow_div.addEventListener('DOMMouseScroll', wheel, false);
	fotoflow_div.onmousewheel = wheel;
}

/* This function is called to drag an object (= slider div) */
function dragstart(element)
{
	dragobject = element;
	dragx = posx - dragobject.offsetLeft + new_slider_pos;
}

/* This function is called to stop dragging an object */
function dragstop()
{
	dragobject = null;
	dragging = false;
}

/* This function is called on mouse movement and moves an object (= slider div) on user action */
function drag(e)
{
	posx = document.all ? window.event.clientX : e.pageX;
	if(dragobject != null)
	{
		dragging = true;
		new_posx = (posx - dragx) + conf_slider_width;

		/* Make sure, that the slider is moved in proper relation to previous movements by the glideTo function */
		if(new_posx < ( - new_slider_pos)) new_posx = - new_slider_pos;
		if(new_posx > (scrollbar_width - new_slider_pos)) new_posx = scrollbar_width - new_slider_pos;
		
		var slider_pos = (new_posx + new_slider_pos);
		var step_width = slider_pos / ((scrollbar_width) / (max-1));
		var image_number = Math.round(step_width);
		var new_target = (image_number) * -xstep;
		var new_caption_id = image_number;

		dragobject.style.left = new_posx + 'px';
		glideTo(new_target, new_caption_id);
	}
}

/* Initialize mouse event listener */
function initMouseDrag()
{
	document.onmousemove = drag;
	document.onmouseup = dragstop;
	
	/* Avoid text and image selection while dragging  */
	document.onselectstart = function () 
	{
		if (dragging == true)
		{
			return false;
		}
		else
		{
			return true;
		}
	}
}

function getKeyCode(event)
{
	event = event || window.event;
	return event.keyCode;
}

document.onkeydown = function(event)
{
	var charCode  = getKeyCode(event);
	switch (charCode)
	{
		/* Right arrow key */
		case 39:
			handle(-1);
			break;
		
		/* Left arrow key */
		case 37:
			handle(1);
			break;
	}
}