(function($){
	
	$.fn.noisy = function(options) {
		options = $.extend({}, $.fn.noisy.defaults, options);
		
		// set randomColors to false if you set color option
		if ( typeof options.color !== 'undefined' ) {
			options.randomColors = false;
		}
		var uri, localStorageSupported, cachedUri = false;
		
		try {
			localStorageSupported = true;
			localStorage.setItem("test", "");
			localStorage.removeItem("test");
			cachedUri = localStorage.getItem(window.JSON.stringify(options));
		} catch(e) {
			localStorageSupported = false;
		}
		
		// Use localStorage cache if these options have been used before
		if (cachedUri && !options.disableCache) {
			uri = cachedUri;
		}
		else {
			var canvas = document.createElement('canvas');
			
			// Use fallback image if canvas isn't supported
			if (!canvas.getContext) {
				uri = options.fallback;
			}
			else {
				canvas.width = canvas.height = options.size;
			
				var ctx = canvas.getContext('2d'),
				    imgData = ctx.createImageData(canvas.width, canvas.height),
				    numPixels = Math.round( options.intensity * Math.pow(options.size, 2) ),
				    maxAlpha = 255 * options.opacity;
				    
				// Add color to random pixels in the canvas
				while (numPixels--) { // Read about the double bitwise NOT trick here: goo.gl/6DPpt
					var x = ~~(Math.random()*canvas.width),
					    y = ~~(Math.random()*canvas.height),
					    index = (x + y * imgData.width) * 4;

					if (options.randomColors) {
						var colorChannel = numPixels % 255; // This will look random enough
						if (options.colorChannels === parseInt(options.colorChannels)) {
							colorChannel = numPixels % options.colorChannels;
						} else if ($.isArray(options.colorChannels)) {
							colorChannel = options.colorChannels[0] + (numPixels % (options.colorChannels[1]-options.colorChannels[0]));
						}
						
						imgData.data[index] = colorChannel;                                               // red
						imgData.data[index+1] = options.monochrome ? colorChannel : ~~(Math.random()*255);  // green
						imgData.data[index+2] = options.monochrome ? colorChannel : ~~(Math.random()*255);  // blue
						imgData.data[index+3] = ~~(Math.random()*maxAlpha);                                 // alpha
					} else {
						var rgb = hexToRgb(options.color);
						imgData.data[index] = rgb.r;
						imgData.data[index+1] = rgb.g;
						imgData.data[index+2] = rgb.b;
				        	imgData.data[index+3] = ~~(Math.random()*maxAlpha);
					}
				}
				
				ctx.putImageData(imgData, 0, 0);
				uri = canvas.toDataURL('image/png');
				
				// toDataURL doesn't return anything in Android 2.2
				if (uri.indexOf('data:image/png') != 0) {
					uri = options.fallback;
				}
			}
			
			if (window.JSON && localStorageSupported && !options.disableCache) {
				try {
					localStorage.setItem(window.JSON.stringify(options), uri);
				} catch(e) {
					console.warn(e.message);
				}
			}
		}

		function hexToRgb(hex) {
			var result = /^#?([a-f\d]{2})([a-f\d]{2})([a-f\d]{2})$/i.exec(hex);
			return result ? {
				r: parseInt(result[1], 16),
				g: parseInt(result[2], 16),
				b: parseInt(result[3], 16)
			} : null;
		}
		
		return this.each(function() {
			$(this).css('background-image', "url('" + uri + "')," + $(this).css('background-image'));
		});
	};
	$.fn.noisy.defaults = {
		// How many percent of the image that is filled with noise, 
		//   represented by a number between 0 and 1 inclusive
		intensity:          0.9,
		
		// The width and height of the image in pixels
		size:               200,
		
		// The maximum noise particle opacity,
		//   represented by a number between 0 and 1 inclusive
		opacity:            0.08,
		
		// A string linking to the image used if there's no canvas support
		fallback:           '',
		
		// Specifies wheter the particles are grayscale or colorful
		monochrome:         false,
		
		// The range of color channels to use for random color and monochrome noise
		//   if a number, sets the upper range (max 255)
		//   if an array, e.g. [200,255], sets the lower and upper range
		colorChannels:     255,

		// Specifies where the particles color are random or not, you can set color with color option
		randomColors:      true,
		
		// Disables the use of localStorage if enabled (good when trying different settings)
		disableCache:      false
	};
})(jQuery);