/////////////////////////////////////////////////////////////////
//  Shift Hues
////////////////////////////////////////////////////////////////// 
//Inspired by  John Wundes ( john@wundes.com ) www.wundes.com "Vary hues" script : http://www.wundes.com/JS4AI/vary_hues.js
//Copyleft Laurent Jégou, jegou@univ-tlse2.fr, 10/09

var ad = app.activeDocument;
var len = ad.selection.length;
var hues = false;
if (len == 0) {
	alert("One or more object must be selected.");
} else {
	ob = app.activeDocument.selection;
	var text = "To shift hues, enter the shift value (on a scale of 360) such as: 20 (could be negative)\n"

	var data = prompt(text, "");
	if ( data == null || data.length ==0 )
	{
	//User canceled process or didn't enter anything, so do nothing and end nicely.
	} else{	 
	//Value detection
	action = Number(data);
	hues = true;
	for (j=0; j<len; j++) {
		//
		if (isNumber(action, 360) && hues == true) {
			if (ob[j].filled == true) {
				setHue(ob[j].fillColor, setLegal(action, 360));
			}
		} else {
			//break
			j = len;
			error(action);
		}
	}
}

function error(val) {
	alert(val+" is not a correct value.");
}

function isNumber(num, max) {
	if (max == undefined) {
		max = 100;
	}
	if (num>=-max && num<=max) {
		return true;
	}
	return false;
}
function setLegal(num, max) {
	if (max == undefined) {
		max = 100;
	}
	if (num<-max) {
		return -num%max;
	} else if (num>max) {
		return max-(num%max);
	} else {
		return num;
	}
}

function setHue(obj, dev) {
	if (obj == undefined) {
		alert ("Error : object undefined.");
	} else if (obj.typename == "RGBColor") {
		var trgb = new rgbc();
		trgb.r = obj.red;
		trgb.g = obj.green;
		trgb.b = obj.blue;
		var thsv = new hsvc();
		thsv = RGB2HSV(trgb);
		thsv.h += dev;
		if (thsv.h < 0) {
			thsv.h += 360;
		}
		if (thsv.h > 360) {
			thsv.h -= 360;
		}
		var trgb = HSV2RGB(thsv);
		obj.red = trgb.r;
		obj.green = trgb.g;
		obj.blue = trgb.b;
	} else if (obj.typename == "SpotColor") {
		alert("Object has a spot color, please use RGB colors.");
	} else if (obj.typename == "GrayColor") {
		alert("Object has a greyscale color, please use RGB colors.");
	} else if (obj.typename == "CMYKColor") {
		alert("Object has a CYMK color, please use RGB colors.");
	} else if (gradAlert != 1 && (obj.typename == "PatternColor" || obj.typename == "GradientColor")) {
		var gradAlert = 1;
		alert("Patterns and Gradients will not be transformed.");
	}
}

function hsvc() {
	this.h = 0;
	this.s = 0;
	this.v = 0;
}

function rgbc() {
	this.r = 0;
	this.g = 0;
	this.b = 0;
}

function cymkc() {
	this.c = 0;
	this.y = 0;
	this.m = 0;
	this.k = 0;
}

function cymc() {
	this.c = 0;
	this.y = 0;
	this.m = 0;
}

function RGB2HSV(obj) {
	var rhsv = new hsvc();
	
	var var_R = ( obj.r / 255 );                   //RGB from 0 to 255
	var var_G = ( obj.g / 255 );
	var var_B = ( obj.b / 255 );

	var minRG = Math.min(var_R, var_G);
	var var_Min = Math.min(minRG, var_B);    //Min. value of RGB
	var maxRG = Math.max(var_R, var_G);
	var var_Max = Math.max(maxRG, var_B);    //Max. value of RGB
	var del_Max = var_Max - var_Min;             //Delta RGB value

	rhsv.v = var_Max;

	if ( del_Max == 0 )                     //This is a gray, no chroma...
	{
	   rhsv.h = 0;                                //HSV results from 0 to 1
	   rhsv.s = 0;
	}
	else                                    //Chromatic data...
	{
	   rhsv.s = del_Max / var_Max;

	   var del_R = ( ( ( var_Max - var_R ) / 6 ) + ( del_Max / 2 ) ) / del_Max;
	   var del_G = ( ( ( var_Max - var_G ) / 6 ) + ( del_Max / 2 ) ) / del_Max;
	   var del_B = ( ( ( var_Max - var_B ) / 6 ) + ( del_Max / 2 ) ) / del_Max;

	   if ( var_R == var_Max ) {
		   rhsv.h = del_B - del_G;
	  } else if ( var_G == var_Max ) {
		  rhsv.h = ( 1 / 3 ) + del_R - del_B;
	  } else if ( var_B == var_Max ) {
		  rhsv.h = ( 2 / 3 ) + del_G - del_R;
	  }
	   if ( rhsv.h < 0 ) {rhsv.h += 1;}
	   if ( rhsv.h > 1 ) {rhsv.h -= 1;}
	}

	rhsv.h *= 360;
	rhsv.s *= 100;
	rhsv.v *= 100;
	return rhsv;
}

function HSV2RGB(obj) {
	var argb = new rgbc();

	if (obj.s == 0) {
			argb.r = obj.v;
			argb.g = obj.v;
			argb.b = obj.v;
			return argb;
	}

	obj.h /= 360;
	obj.s /= 100;
	obj.v /= 100;
	
	var var_r = 0;
	var var_g = 0;
	var var_b = 0;

	   var var_h = obj.h * 6;
	   if ( var_h == 6 ) var_h = 0;      //H must be < 1
	   var var_i = Math.floor( var_h );             //Or ... var_i = floor( var_h )
	   var var_1 =obj.v * ( 1 - obj.s )
	   var var_2 = obj.v * ( 1 - obj.s * ( var_h - var_i ) )
	   var var_3 = obj.v * ( 1 - obj.s * ( 1 - ( var_h - var_i ) ) )

	   if (var_i == 0) {
		   var_r = obj.v;
		   var_g = var_3;
		   var_b = var_1;
	   } else if (var_i == 1) {
		   var_r = var_2;
		   var_g = obj.v;
		   var_b = var_1;
	  } else if (var_i == 2) {
		   var_r = var_1;
		   var_g = obj.v;
		   var_b = var_3;
	  }  else if (var_i == 3) {
		  var_r = var_1;
		  var_g = var_2;
		  var_b = obj.v;
	  } else if (var_i == 4) {
		  var_r = var_3;
		  var_g = var_1;
		  var_b = obj.v;
	  } else {
		  var_r = obj.v;
		  var_g = var_1;
		  var_b = var_2;
	  }
	  argb.r = var_r * 255;
	  argb.g = var_g * 255;
	  argb.b = var_b * 255;

	return argb;
}
}