using UnityEngine.Events;

namespace AssetManagement
{
    // 2020.01.04 - Blastom：因为当前版本UnityWebRequest不支持下载https
    // 现在下载部分无法重用AsyncLoadHub
    // 快速解决方案是复制AsyncLoadHub 修改为支持BestHttp的流程
    // BestHttp当前没有找到 支持直接下载到文件流的方法，暂时只能下载到内存，然后转存到硬盘
    public class BundleDownloader
    {
        private AssetUpdateDownloader _downloader;
        private AssetPathHub pathHub;
        public string name { get; private set; }
        public int priority { get; set; }
        public string error { get; private set; }

        public AsyncLoadUnitState state { get; private set; }
        public AssetUpdateDownloaderTick.DownloadTimer downloadTimer { get; private set; }

        // 失败重试次数
        public int failCount { get; private set; }

        public event UnityAction<BundleDownloader> onComplete;

        // 等待时间结束
        public event UnityAction<BundleDownloader> onWaitUp;

        public void SetRetry(float time)
        {
            failCount++;
            state = AsyncLoadUnitState.Idle;
            downloadTimer = AssetUpdateDownloaderTick.instance.AddTimer(time, OnWaitFinish);
        }

        public void Init(AssetPathHub pathHub, string assetName, int priority)
        {
            name = assetName;
            this.priority = priority;
            this.pathHub = pathHub;
        }

        public void Load()
        {
            if (state != AsyncLoadUnitState.Loading)
            {
                error = string.Empty;
                var uriPath = pathHub.GetDownloadPath(name) + AssetConst.bundleVariant;
                _downloader =
                    new AssetUpdateDownloader(uriPath, pathHub.GetPersistPath(name + AssetConst.bundleVariant))
                        {onComplete = OnComplete};
                _downloader.Start(30f);
            }
        }

        // 取消下载，仅仅在关闭App时调用
        public void Dispose()
        {
            if (_downloader != null)
            {
                _downloader.onComplete = null;
                _downloader.Dispose();
            }

            _downloader = null;
        }

        public float GetProgress()
        {
            return _downloader == null ? 0f : _downloader.progress;
        }

        private void OnWaitFinish()
        {
            AssetUpdateDownloaderTick.instance.RemoveTimer(OnWaitFinish);
            downloadTimer = null;
            if (onWaitUp != null)
                onWaitUp(this);
        }

        private void OnComplete(AssetUpdateDownloader downloader)
        {
            if (downloader.error == AssetUpdateManager.AssetUpdateError.FileCreateError)
                error = string.Format("File Create Error: failed to create file for {0}!", name);
            else if (downloader.error != AssetUpdateManager.AssetUpdateError.Success)
                error = string.Format("Download Error: failed to download file for {0}!", name);
            else
                error = string.Empty;
            state = AsyncLoadUnitState.Done;
            if (onComplete != null)
                onComplete(this);
        }
    }
}