#target photoshop
app.bringToFront()

function workIt() {
	var overlapWidth = UnitValue(wnd.panel1.formatX.text, "px");
	var overlapHeight = UnitValue(wnd.panel1.formatY.text, "px");
	var overlapPercent = (100 - wnd.panel1.overlapChooser.value)/100;
	
	if(wnd.panel1.resampleMethodChooser.selection.text == "Bicubic") var resampleMethod = ResampleMethod.BICUBIC;
	if(wnd.panel1.resampleMethodChooser.selection.text == "Bicubic Sharper") var resampleMethod = ResampleMethod.BICUBICSHARPER;	
	if(wnd.panel1.resampleMethodChooser.selection.text == "Bicubic Smoother") var resampleMethod = ResampleMethod.BICUBICSMOOTHER;

	if(overlapWidth != 0 && overlapHeight != 0) {
		// store units
		var startRulerUnits = app.preferences.rulerUnits;
		var startTypeUnits = app.preferences.typeUnits;
		var startDisplayDialogs = app.displayDialogs;

		// modify units to pixels
		app.preferences.rulerUnits = Units.PIXELS;
		app.preferences.typeUnits = TypeUnits.PIXELS;
		app.displayDialogs = DialogModes.NO;
		
		var myDoc = app.activeDocument;
		selectAllLayers();
		makeSelectedLayersSmartObject(myDoc.name);
		
		// if image is not in portrait mode => swap overlapWidth and overlapHeight
		if(myDoc.width >= myDoc.height) {
			var tmp = overlapWidth;
			overlapWidth = overlapHeight;
			overlapHeight = tmp;
		}
	
		var myNewImageWidth = overlapWidth * overlapPercent;
		var myNewImageHeight = overlapHeight * overlapPercent;
		
		if(myDoc.width != myNewImageWidth || myDoc.height < myNewImageHeight) {
			if((myNewImageWidth - myDoc.width) < (myNewImageHeight - myDoc.height)) {
				myDoc.resizeImage(myNewImageWidth, undefined, 400, resampleMethod);
			}
			else {
				myDoc.resizeImage(undefined, myNewImageHeight, 400, resampleMethod);
			}
		}
		
		myDoc.resizeCanvas(overlapWidth, overlapHeight);
		
		var myLayer = myDoc.artLayers.add();
		var colorGray = new SolidColor();		
		colorGray.rgb.hexValue = "a1a1a1";
		myDoc.selection.selectAll();
		myDoc.selection.fill (colorGray);
		myDoc.selection.deselect();
		myLayer.isBackgroundLayer = true;
		
		zoomToFit();
		
		// resets units
		app.preferences.rulerUnits = startRulerUnits;
		app.preferences.typeUnits = startTypeUnits;
		app.displayDialogs = startDisplayDialogs;
	}
}

function selectAllLayers() {
	var layerNum = app.activeDocument.layers.length;
	for(var i = 0; i < layerNum; i++) {
		var layer = app.activeDocument.layers[i];
		selectLayer(layer.name, (i>0));
	}
}

function selectLayer(layerName, addToSelection) {
	var id84 = charIDToTypeID( "slct" );
    var desc18 = new ActionDescriptor();
    var id85 = charIDToTypeID( "null" );
	var ref13 = new ActionReference();
	var id86 = charIDToTypeID( "Lyr " );
	ref13.putName( id86, layerName );
    desc18.putReference( id85, ref13 );
    
	if(addToSelection) {
		var id87 = stringIDToTypeID( "selectionModifier" );
		var id88 = stringIDToTypeID( "selectionModifierType" );
		var id89 = stringIDToTypeID( "addToSelection" );
		desc18.putEnumerated( id87, id88, id89 );
	}
    
	var id90 = charIDToTypeID( "MkVs" );
    desc18.putBoolean( id90, false );
	executeAction( id84, desc18, DialogModes.NO );
}

function makeSelectedLayersSmartObject(layerName) {
	// merge to SmartObject
	var id34 = stringIDToTypeID( "newPlacedLayer" );
	executeAction( id34, undefined, DialogModes.NO );
	
	// rename SmartObject to layerName
	var id35 = charIDToTypeID( "setd" );
    var desc7 = new ActionDescriptor();
    var id36 = charIDToTypeID( "null" );
	var ref5 = new ActionReference();
	var id37 = charIDToTypeID( "Lyr " );
	var id38 = charIDToTypeID( "Ordn" );
	var id39 = charIDToTypeID( "Trgt" );
	ref5.putEnumerated( id37, id38, id39 );
    desc7.putReference( id36, ref5 );
    var id40 = charIDToTypeID( "T   " );
	var desc8 = new ActionDescriptor();
	var id41 = charIDToTypeID( "Nm  " );
	desc8.putString( id41, layerName );
    var id42 = charIDToTypeID( "Lyr " );
    desc7.putObject( id40, id42, desc8 );
	executeAction( id35, desc7, DialogModes.NO );
}

function zoomToFit() {
	var id29 = charIDToTypeID( "slct" );
    var desc7 = new ActionDescriptor();
    var id30 = charIDToTypeID( "null" );
	var ref2 = new ActionReference();
	var id31 = charIDToTypeID( "Mn  " );
	var id32 = charIDToTypeID( "MnIt" );
	var id33 = charIDToTypeID( "FtOn" );
	ref2.putEnumerated( id31, id32, id33 );
    desc7.putReference( id30, ref2 );
	executeAction( id29, desc7, DialogModes.NO ); 
}

/* **************************************************************************************************************** */

var printFormats = new Array();
printFormats.push("fcprints print formats");
printFormats.push("-");
printFormats.push("9x13cm (1339*2000px)");
printFormats.push("-");
printFormats.push("10x13cm (1606*2142px)");
printFormats.push("10x15cm (1606*2394px)");
printFormats.push("10x20cm (1606*3150px)");
printFormats.push("-");
printFormats.push("13x13cm (2000*2000px)");
printFormats.push("13x17cm (2000*2661px)");
printFormats.push("13x18cm (2000*2803px)");
printFormats.push("13x19,05cm (2000*3000px)");
printFormats.push("-");
printFormats.push("15x20cm (2394*3197px)");
printFormats.push("15x21cm (2502*3307px)");
printFormats.push("-");
printFormats.push("18x24cm (2803*3780px)");
printFormats.push("-");
printFormats.push("20x20cm (3197*3197px)");
printFormats.push("20x25cm (3197*4000px)");
printFormats.push("20x28cm (3197*4409px)");
printFormats.push("20x30cm (3197*4803px)");
printFormats.push("-");
printFormats.push("21x21cm (3307*3307px)");
printFormats.push("21x28cm (3307*4409px)");
printFormats.push("21x29,7cm A4 (3307*4677px)");
printFormats.push("-");
printFormats.push("24x30cm (3780*4803px)");
printFormats.push("-");
printFormats.push("25x25cm (4000*4000px)");
printFormats.push("-");
printFormats.push("30x30cm (4803*4803px)");
printFormats.push("30x40cm (4803*6331px)");
printFormats.push("30x45cm (4803*7118px)");

var resampleMethods = new Array();
resampleMethods.push("Bicubic");
resampleMethods.push("Bicubic Sharper");
resampleMethods.push("Bicubic Smoother");

/* **************************************************************************************************************** */

var wnd = new Window('dialog', 'fotocommunity Prints: Print-Assistant');

// Bereich: Format
wnd.panel1 = wnd.add('panel', [10, 10, 390, 150], 'Parameters');

wnd.panel1.add('statictext', [10, 22, 110, 40], "Format");

wnd.panel1.formatChooser = wnd.panel1.add('dropdownlist', [120, 20, 335, 40], printFormats);
wnd.panel1.formatX = wnd.panel1.add('edittext', [120, 45, 180, 65], '');
wnd.panel1.add('statictext', [185, 47, 192, 65], ' x ');
wnd.panel1.formatY = wnd.panel1.add('edittext', [197, 45, 257, 65], '');
wnd.panel1.add('statictext', [263, 47, 285, 65], 'px');

wnd.panel1.formatChooser.selection = 0;
wnd.panel1.formatChooser.onChange = function() {
	var format = wnd.panel1.formatChooser.selection.text;
	if(format != null) {
			format = format.split("(")[1];
			format = format.split("px)")[0];
			format = format.split("*");
			wnd.panel1.formatX.text = format[0];
			wnd.panel1.formatY.text = format[1];
		}
	}

wnd.panel1.add('statictext', [10, 75, 110, 95], "Overlap");
wnd.panel1.overlapChooser = wnd.panel1.add('slider', [120, 75, 335, 95], 2, 0, 100);
wnd.panel1.overlapChooserValue = wnd.panel1.add('statictext', [345, 75, 485, 95], wnd.panel1.overlapChooser.value + "%");
wnd.panel1.overlapChooser.onChanging = function() {
		wnd.panel1.overlapChooserValue.text = wnd.panel1.overlapChooser.value + "%";
	};

wnd.panel1.add('statictext', [10, 107, 110, 125], "Resample-Method");
wnd.panel1.resampleMethodChooser = wnd.panel1.add('dropdownlist', [120, 105, 335, 125], resampleMethods);
wnd.panel1.resampleMethodChooser.selection = 0;

// Bereich: Ausführen
wnd.panel2 = wnd.add('panel', [10, 160, 390, 220], 'Execute');
wnd.panel2.okButton = wnd.panel2.add('button', [20, 15, 70, 40], 'OK', {name: 'ok'});
wnd.panel2.abortButton = wnd.panel2.add('button', [80, 15, 150, 40], 'Cancel', {name: 'cancel'});

// Anzeige
if(wnd.show() == 1) workIt();