PS Script – creating groups and subgroups based on layer names

Hey, I have a script that creates groups and subgroups based on layer names and moves them to the appropriate places. Below is a description of how it works:

1. Creates groups based on layer names. The group name is to consist of the layer name up to the first character "_".

2. Creates subgroups in these groups based on the layer names up to the second "_" character

3. Moves all the layers corresponding to the subgroup name to this subgroup

4. Creates an exception for layers with a string in the name "Texture”, “mask” or “Shadow”. Create a group named like this string and move these layers to it.

Everything works fine, but I don't know why the script skips a large part of the layers, even though they meet the criteria. I marked the problem on the screen. Could someone suggest how to fix it?

#target photoshop;

var doc = app.activeDocument;
var layers = doc.layers;
var groups = {};

for (var i = 0; i < layers.length; i++) {
  var layer = layers[i];
  var layerName = layer.name;

  if (layerName.indexOf("Texture") !== -1) {
    if (!groups["Texture"]) {
      groups["Texture"] = doc.layerSets.add();
      groups["Texture"].name = "Texture";
    }
    layer.move(groups["Texture"], ElementPlacement.INSIDE);
    continue;
  } else if (layerName.indexOf("mask") !== -1) {
    if (!groups["mask"]) {
      groups["mask"] = doc.layerSets.add();
      groups["mask"].name = "mask";
    }
    layer.move(groups["mask"], ElementPlacement.INSIDE);
    continue;
  } else if (layerName.indexOf("Shadow") !== -1) {
    if (!groups["Shadow"]) {
      groups["Shadow"] = doc.layerSets.add();
      groups["Shadow"].name = "Shadow";
    }
    layer.move(groups["Shadow"], ElementPlacement.INSIDE);
    continue;
  }

  var firstUnderscoreIndex = layerName.indexOf("_");
  var groupName = layerName.substring(0, firstUnderscoreIndex);
  var secondUnderscoreIndex = layerName.indexOf("_", firstUnderscoreIndex + 1);
  var subgroupName;
  
  if (secondUnderscoreIndex === -1) {
    subgroupName = groupName;
  } else {
    subgroupName = layerName.substring(0, secondUnderscoreIndex);
  }

  if (!groups[groupName]) {
    groups[groupName] = doc.layerSets.add();
    groups[groupName].name = groupName;
  }

  if (!groups[subgroupName]) {
    groups[subgroupName] = groups[groupName].layerSets.add();
    groups[subgroupName].name = subgroupName;
  }

  layer.move(groups[subgroupName], ElementPlacement.INSIDE);
}