namespace YooAsset
{
	internal class VirtualBundleFileLoader : BundleLoaderBase
	{
		private enum ESteps
		{
			None,
			CheckFile,
			Done,
		}

		private ESteps _steps = ESteps.None;

		public VirtualBundleFileLoader(AssetSystemImpl impl, BundleInfo bundleInfo) : base(impl, bundleInfo)
		{
		}

		/// <summary>
		/// 轮询更新
		/// </summary>
		public override void Update()
		{
			if (_steps == ESteps.Done)
				return;

			if (_steps == ESteps.None)
			{
				if (MainBundleInfo.LoadMode == BundleInfo.ELoadMode.LoadFromEditor)
				{
					_steps = ESteps.CheckFile;
				}
				else
				{
					throw new System.NotImplementedException(MainBundleInfo.LoadMode.ToString());
				}
			}

			// 1. 检测结果
			if (_steps == ESteps.CheckFile)
			{
				// 设置下载进度
				DownloadProgress = 1f;
				DownloadedBytes = (ulong)MainBundleInfo.Bundle.FileSize;

				_steps = ESteps.Done;
				Status = EStatus.Succeed;
			}
		}

		/// <summary>
		/// 主线程等待异步操作完毕
		/// </summary>
		public override void WaitForAsyncComplete()
		{
			int frame = 1000;
			while (true)
			{
				// 保险机制
				// 注意：如果需要从远端下载资源，可能会触发保险机制！
				frame--;
				if (frame == 0)
				{
					if (IsDone() == false)
					{
						Status = EStatus.Failed;
						LastError = $"WaitForAsyncComplete failed ! Try load bundle : {MainBundleInfo.Bundle.BundleName} from remote with sync load method !";
						YooLogger.Error(LastError);
					}
					break;
				}

				// 驱动流程
				Update();

				// 完成后退出
				if (IsDone())
					break;
			}
		}
	}
}