Dynamic stylesheet loading

using System;
using System.Collections;
using System.Collections.Generic;
using System.Reflection;
using Cityscaper;
using Cityscaper.Types;
using UnityEditor;
using UnityEngine;
using UnityEngine.UIElements;

public enum ScreenSizePrefix
{
    sm,
    lg
}

[RequireComponent(typeof(UIDocument))]
public class ScreenDependentStylesheets : MonoBehaviour
{
    private UIDocument root;
    private Dictionary<ScreenSizePrefix, List<StyleSheet>> sheets;
    public float[] breakpoints = new[] {0.15f}; // in cm
    private List<StyleSheet> loadedStylesheets;

    void Start()
    {
        root = GetComponent<UIDocument>();
        if (breakpoints.Length != Enum.GetNames(typeof(ScreenSizePrefix)).Length - 1)
        {
            Debug.LogWarning("The amount of breakpoints configured do not match the amount of screen size prefixes.");
        }
        UI.Instance.resolutionChanged += (res) => updateScreenSize(res);
        loadedStylesheets = new List<StyleSheet>();
    }

    void updateScreenSize(Vector2 res)
    {
        if (root.rootVisualElement == null)
        {
            return;
        }
        if (root.rootVisualElement.styleSheets.count > 0 && sheets == null)
        {
            loadInitalReplacementSheets();
        }
        float screenWidthInMeters = ((float)Screen.width / Screen.dpi) * 0.0254f;

        int breakpoint;
        for (breakpoint = 0; breakpoint < breakpoints.Length; breakpoint++)
        {
            if (screenWidthInMeters < breakpoints[breakpoint])
            {
                break;
            }
        }

        ScreenSizePrefix prefix = (ScreenSizePrefix)breakpoint;

        List<StyleSheet> newStyleSheets = sheets[prefix];
        List<StyleSheet> sheetsToRemove = loadedStylesheets.FindAll((loaded) => !newStyleSheets.Contains(loaded));
        List<StyleSheet> sheetsToAdd = newStyleSheets.FindAll((news) => !loadedStylesheets.Contains(news));

        foreach (var sheet in sheetsToRemove)
        {
            loadedStylesheets.Remove(sheet);
            root.rootVisualElement.styleSheets.Remove(sheet);
        }

        foreach (var sheet in sheetsToAdd)
        {
            loadedStylesheets.Add(sheet);
            root.rootVisualElement.styleSheets.Add(sheet);
        }

        if (sheetsToAdd.Count > 0 || sheetsToRemove.Count > 0)
        {
            Debug.Log(string.Format("Loaded Stylesheets for {0}. Screen size: {1}cm. Sheets:",
                Enum.GetName(typeof(ScreenSizePrefix), prefix), screenWidthInMeters * 100.0f));
            foreach (var sheet in loadedStylesheets)
            {
                Debug.Log(sheet.name);
            }
        }
    }

    private void loadInitalReplacementSheets()
    {
        // Debug.Log("Loading pseudo size stylesheets. Root styles: " + root.rootVisualElement.styleSheets.count);
        sheets = new Dictionary<ScreenSizePrefix, List<StyleSheet>>();
        int totalSheetsLoaded = 0;
        for(int i = 0; i < root.rootVisualElement.styleSheets.count; i++)
        {
            var sheet = root.rootVisualElement.styleSheets[i];
            foreach (ScreenSizePrefix prefix in Enum.GetValues(typeof(ScreenSizePrefix)))
            {
                if (!sheets.ContainsKey(prefix))
                {
                    sheets.Add(prefix, new List<StyleSheet>());
                }

                string sheetPath = Enum.GetName(typeof(ScreenSizePrefix), prefix) + "_" + sheet.name;
                StyleSheet ls =
                    Resources.Load<StyleSheet>(sheetPath);
                if (ls != null)
                {
                    sheets[prefix].Add(ls);
                    totalSheetsLoaded++;
                }
                else
                {
                    Debug.LogWarning("Failed to load: " + sheetPath);
                }
            }
        }
        // Debug.Log("Pseudosheets loaded: " + totalSheetsLoaded);
    }
}