Pong/Assets/Scripts/GameUI.cs

using System;
using System.Collections.Generic;
using System.Linq;
using Game;
using UnityEngine;
using UnityEngine.Assertions;
using UnityEngine.UIElements;

public class GameUI : MonoBehaviour {

	private UIDocument document;
	public static GameUI Singleton;
	private void Awake() {
		Singleton = this;
		document = GetComponent<UIDocument>();
		PreparePlayerPanels();
	}
	
	private List<VisualElement> PlayerPanels => document.rootVisualElement.Children().Where(e => e.ClassListContains("player_panel")).ToList();

	public VisualElement PlayerPanel(Side side) {
		return side switch {
			Side.Top => PlayerPanels[0],
			Side.Bottom => PlayerPanels[1],
			_ => throw new ArgumentOutOfRangeException(nameof(side), side, null)
		};
	}
	
	// TODO create correct visual element, attach it to panel with background-image and return it
	public static VisualElement AddModification(VisualElement playerPanel, ActiveModification modification) {
		VisualElement listElement = ModsList(playerPanel, modification.Properties.Type);
		
		return listElement;
	}

	private static VisualElement ModsList(VisualElement player, ModType type) {
		return type switch {
			ModType.Buff => player.Children().First(e => e.ClassListContains("mods_list")),
			ModType.Nerf => player.Children().Last(e => e.ClassListContains("mods_list")),
			_ => throw new ArgumentOutOfRangeException(nameof(type), type, null)
		};
	}

	void PreparePlayerPanels() {
		var players = PlayerPanels;
		Assert.AreEqual(players.Count, 2);

		float heightPercentage = Dimensions.Singleton.panelHeightPercentage;
		foreach (var playerPanel in players)
			playerPanel.style.height = Length.Percent(heightPercentage);
	}
}