/**
 * Copyright (c) 2006-2009 Texas Wildlife Unlimited, Inc.
 * 
 * All rights reserved.
 */

function MediaRotator(aryImgTagIDs, aryImgUrls, aryLinkUrls, rotationDelay) {
	this._imgTagIDs = aryImgTagIDs;
	this._imgUrls = aryImgUrls;
	this._linkUrls = aryLinkUrls;
	this._rotationDelay = rotationDelay;

	// transient data
	this._index = 0;

	this.nextRotation = function() {
		this._index++;
		for (var i = 0; i < this._imgTagIDs.length; i++) {
			var img = document.getElementById(this._imgTagIDs[i]);
			var link = document.getElementById('link_' + this._imgTagIDs[i]);
			var ind = this.getCurrentImageIndex(i);
			img.src = this._imgUrls[ind];
			link.href = this._linkUrls[ind];
		}
		this.setRotationDelay();
	}

	this.getCurrentImageIndex = function(imgSpot) {
		var ind = this._index + imgSpot;
		while (ind >= this._imgUrls.length) {
			ind -= this._imgUrls.length;
		}
		return ind;
	}

	this.startRotation = function() {
		this.setRotationDelay();
	}
	
	this.setRotationDelay = function() {
		var self = this;
		setTimeout(function() {
			self.nextRotation();
		},  this._rotationDelay)
	}
}