#target illustrator

if (app.documents.length === 0) {
    alert("No document open");
    exit();
}

var doc = app.activeDocument;

// ================= UI =================
var win = new Window("dialog", "CTP Sheet Optimizer");

win.alignChildren = "left";

// Sheet Panel
var pSheet = win.add("panel", undefined, "Sheet Size");
pSheet.orientation = "grid";
pSheet.add("statictext", undefined, "Width:");
var sheetW = pSheet.add("edittext", undefined, "23");
sheetW.characters = 6;
pSheet.add("statictext", undefined, "Height:");
var sheetH = pSheet.add("edittext", undefined, "36");
sheetH.characters = 6;

// Design Source
var pSource = win.add("panel", undefined, "Design Size From");
pSource.orientation = "column";
var rSel = pSource.add("radiobutton", undefined, "Selected Object");
var rArt = pSource.add("radiobutton", undefined, "Artboard");
rSel.value = true;

// Spacing
var pSpace = win.add("panel", undefined, "Margin / Gap (mm)");
pSpace.orientation = "grid";
pSpace.add("statictext", undefined, "Margin:");
var margin = pSpace.add("edittext", undefined, "10");
margin.characters = 6;
pSpace.add("statictext", undefined, "Gap:");
var gap = pSpace.add("edittext", undefined, "5");
gap.characters = 6;

// Rotation
var rotateChk = win.add("checkbox", undefined, "Allow 90° Rotation");
rotateChk.value = true;

// Result
var pResult = win.add("panel", undefined, "Result");
pResult.orientation = "column";
var resultTxt = pResult.add("statictext", undefined, "", {multiline:true});
resultTxt.preferredSize.width = 260;
resultTxt.preferredSize.height = 80;

// Buttons
var btnGroup = win.add("group");
var calcBtn = btnGroup.add("button", undefined, "Calculate");
btnGroup.add("button", undefined, "Cancel", {name:"cancel"});

// ================= LOGIC =================
calcBtn.onClick = function () {

    var sheetWidth = parseFloat(sheetW.text);
    var sheetHeight = parseFloat(sheetH.text);

    var m = parseFloat(margin.text) * 2.8346; // mm to pt
    var g = parseFloat(gap.text) * 2.8346;

    var dW, dH;

    if (rSel.value) {
        if (doc.selection.length === 0) {
            alert("Please select an object");
            return;
        }
        var b = doc.selection[0].visibleBounds;
        dW = b[2] - b[0];
        dH = b[1] - b[3];
    } else {
        var ab = doc.artboards[doc.artboards.getActiveArtboardIndex()].artboardRect;
        dW = ab[2] - ab[0];
        dH = ab[1] - ab[3];
    }

    // inch to pt
    sheetWidth *= 72;
    sheetHeight *= 72;

    var usableW = sheetWidth - m;
    var usableH = sheetHeight - m;

    var col1 = Math.floor((usableW + g) / (dW + g));
    var row1 = Math.floor((usableH + g) / (dH + g));
    var total1 = col1 * row1;

    var total2 = 0;
    if (rotateChk.value) {
        var col2 = Math.floor((usableW + g) / (dH + g));
        var row2 = Math.floor((usableH + g) / (dW + g));
        total2 = col2 * row2;
    }

    var best = Math.max(total1, total2);

    resultTxt.text =
        "Normal Fit : " + total1 + " pcs\n" +
        "Rotated Fit: " + total2 + " pcs\n\n" +
        "BEST FIT   : " + best + " pcs per sheet";
};

win.center();
win.show();