// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
using System;
using System.IO;
using System.Reflection;
 
namespace TestResources
{
    internal static class ResourceLoader
    {
        private static Stream GetResourceStream(string name)
        {
            var assembly = typeof(ResourceLoader).GetTypeInfo().Assembly;
 
            var stream = assembly.GetManifestResourceStream(name);
            if (stream == null)
            {
                throw new InvalidOperationException($"Resource '{name}' not found in {assembly.FullName}.");
            }
 
            return stream;
        }
 
        private static byte[] GetResourceBlob(string name)
        {
            using (var stream = GetResourceStream(name))
            {
                var bytes = new byte[stream.Length];
                using (var memoryStream = new MemoryStream(bytes))
                {
                    stream.CopyTo(memoryStream);
                }
 
                return bytes;
            }
        }
 
        public static byte[] GetOrCreateResource(ref byte[] resource, string name)
        {
            if (resource == null)
            {
                resource = GetResourceBlob(name);
            }
 
            return resource;
        }
    }
}