#target photoshop

/*
    Create missing guides at the document origin.
    Existing guides at X=0 or Y=0 are not duplicated.
*/

(function () {
    if (app.documents.length === 0) {
        alert("请先打开一个文档。");
        return;
    }

    try {
        var document = app.activeDocument;
        var hasVerticalAtZero = false;
        var hasHorizontalAtZero = false;
        var tolerance = 0.001;
        var i;

        for (i = 0; i < document.guides.length; i++) {
            var guide = document.guides[i];
            var position = guide.coordinate.as("px");

            if (Math.abs(position) <= tolerance) {
                if (guide.direction === Direction.VERTICAL) {
                    hasVerticalAtZero = true;
                } else if (guide.direction === Direction.HORIZONTAL) {
                    hasHorizontalAtZero = true;
                }
            }
        }

        if (!hasVerticalAtZero) {
            document.guides.add(
                Direction.VERTICAL,
                new UnitValue(0, "px")
            );
        }

        if (!hasHorizontalAtZero) {
            document.guides.add(
                Direction.HORIZONTAL,
                new UnitValue(0, "px")
            );
        }
    } catch (error) {
        alert("创建参考线失败：\n" + error.message);
    }
}());