using System.Threading.Tasks;
using Azure.Storage;
using Azure.Storage.Blobs;
using Azure.Storage.Blobs.Models;

namespace TEAMModelOS.SDK.DI
{
    public static class AzureStorageBlobExtensions
    {
        /// <summary>
        /// 取得指定前置詞的 Blob 名稱的總大小(Bytes)，例如指定目錄名稱為前置詞
        /// </summary>      
        /// <param name="prefix">篩選開頭名稱，Null代表容器總大小</param>
        /// <returns>總大小(Bytes)，如果為Null代表查無前置詞或者發生錯誤</returns>
        public static async Task<long?> GetBlobsSize(this BlobContainerClient client, string prefix = null)
        {
            long? size = 0;
            try
            {                
                await foreach (var item in client.GetBlobsAsync(BlobTraits.None, BlobStates.None, prefix))
                {
                    size += item.Properties.ContentLength;
                };

                return size;
            }
            catch 
            {
                return null;
            }
        }
    }
}