using System.Collections.Generic;
using UnityEngine;

namespace UltimateWater.Internal
{
	public class UtilityShaderVariants
	{
		private readonly Dictionary<int, Material> _Materials;

		private static UtilityShaderVariants _Instance;

		public static UtilityShaderVariants Instance
		{
			get
			{
				if (_Instance == null)
				{
					return _Instance = new UtilityShaderVariants();
				}
				return _Instance;
			}
		}

		public Material GetVariant(Shader shader, string keywords)
		{
			int key = shader.GetInstanceID() ^ keywords.GetHashCode();
			if (!_Materials.TryGetValue(key, out var value))
			{
				value = new Material(shader)
				{
					hideFlags = HideFlags.DontSave,
					shaderKeywords = keywords.Split(' ')
				};
				_Materials[key] = value;
			}
			return value;
		}

		private UtilityShaderVariants()
		{
			_Materials = new Dictionary<int, Material>();
		}
	}
}