#target illustrator

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

var doc = app.activeDocument;

// ================= UI =================
var win = new Window("dialog", "CTP Optimizer v2 - Multi Size");

win.alignChildren = "fill";

// Sheet
var pSheet = win.add("panel", undefined, "Sheet Size");
pSheet.orientation = "row";
pSheet.add("statictext", undefined, "Sheet:");
var sheetInput = pSheet.add("edittext", undefined, "11x14 in");
sheetInput.characters = 15;

// Gap
var pGap = win.add("panel", undefined, "Spacing");
pGap.orientation = "row";
pGap.add("statictext", undefined, "Gap (mm):");
var gapInput = pGap.add("edittext", undefined, "5");
gapInput.characters = 6;

// Quantity
var pQty = win.add("panel", undefined, "Size - Quantity");
pQty.orientation = "column";
var qtyInput = pQty.add("edittext", undefined,
"S-50\nM-20\nL-30\nXL-50", {multiline:true});
qtyInput.preferredSize.height = 100;

// Result
var pRes = win.add("panel", undefined, "Result");
var resTxt = pRes.add("edittext", undefined, "", {multiline:true, readonly:true});
resTxt.preferredSize.height = 160;

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

// ================= LOGIC =================
function parseSheetSize(str) {
    var unit = "in";
    if (str.match(/mm/i)) unit = "mm";
    if (str.match(/cm/i)) unit = "cm";

    var nums = str.match(/([\d\.]+)\s*x\s*([\d\.]+)/i);
    if (!nums) return null;

    var w = parseFloat(nums[1]);
    var h = parseFloat(nums[2]);

    if (unit === "mm") { w *= 2.8346; h *= 2.8346; }
    else if (unit === "cm") { w *= 28.346; h *= 28.346; }
    else { w *= 72; h *= 72; }

    return {w:w, h:h};
}

calcBtn.onClick = function () {

    if (doc.selection.length === 0) {
        alert("Please select one design object");
        return;
    }

    var sheet = parseSheetSize(sheetInput.text);
    if (!sheet) {
        alert("Invalid sheet size format");
        return;
    }

    var gap = parseFloat(gapInput.text) * 2.8346;

    var b = doc.selection[0].visibleBounds;
    var dW = b[2] - b[0];
    var dH = b[1] - b[3];

    var col = Math.floor((sheet.w + gap) / (dW + gap));
    var row = Math.floor((sheet.h + gap) / (dH + gap));
    var perSheet = col * row;

    if (perSheet <= 0) {
        alert("Design too big for sheet");
        return;
    }

    var lines = qtyInput.text.split("\n");
    var out = "";
    var totalPlates = 0;

    for (var i = 0; i < lines.length; i++) {
        if (!lines[i]) continue;
        var p = lines[i].split("-");
        if (p.length !== 2) continue;

        var size = p[0];
        var qty = parseInt(p[1], 10);
        var sheets = Math.ceil(qty / perSheet);

        totalPlates += sheets;

        out += size + " : " +
               perSheet + " pcs/sheet | Qty " +
               qty + " | Sheets " +
               sheets + "\n";
    }

    out += "\nTOTAL PLATES: " + totalPlates;
    resTxt.text = out;
};

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