[UploadApiService]

UploadApiService.cs

using Microsoft.WindowsAzure.Storage.Blob;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.IO;
using System.Net.Http;
using System.Threading.Tasks;
using PNG.ContentHub.GifConversion.Utils;
using PNG.ContentHub.GifConversion.Helpers;
using Microsoft.Extensions.Logging;

namespace PNG.ContentHub.GifConversion.Services
{
    internal class UploadApiService
    {
        private const string RequestUploadUrl = "api/v1.0/upload";
        private const string UploadAlternativeFileUrl = "api/v1.0/upload/assets/{0}/alternative";
        private const string GifContentType = "image/gif";
        private readonly ILogger _logger;

        private string _fileSize;
        private string _fileName;
        private byte[] _fileAsByteArray;


        public UploadApiService(Uri gifUrl, string fileName, ILogger logger)
        {
            _fileName = fileName;
            _fileAsByteArray = gifUrl.ToByteArray();
            _fileSize = _fileAsByteArray.Length.ToString();
            _logger = logger;
        }

        internal async Task SetAlternativeFileToAsset(long entityId)
        {
            var client = MConnector.Client.Raw;

            //First step
            try
            {            
                HttpResponseMessage uploadUrlResponse;
                uploadUrlResponse = await client.SendAsync(GetUploadUrlRequestMessage);
                _logger.LogTrace($"Upload Url request has been sent");

                uploadUrlResponse.EnsureSuccessStatusCode();
                var uploadUrlResponseBody = JObject.Parse(await uploadUrlResponse.Content.ReadAsStringAsync());
                
                //Retrieving direct url for Azure BlockBlob location
                var uploadUrl = uploadUrlResponse.Headers.Location;            
                _logger.LogDebug($"Upload Url response body is: {uploadUrlResponseBody}");
                _logger.LogTrace($"Upload Url is: {uploadUrl}");

                //Second step is to upload Gif url into Azure           
                var cloudBlockBlob = new CloudBlockBlob(uploadUrl);
                
                cloudBlockBlob.Properties.ContentType = GifContentType;
                cloudBlockBlob.Metadata.Add("Filename", _fileName);
                await cloudBlockBlob.UploadFromStreamAsync(new MemoryStream(_fileAsByteArray));
                _logger.LogDebug($"'{_fileName}' file has been uploaded to Azure Blob Storage: {uploadUrlResponseBody}");

                //Third step is to update alternative file
                var json = JsonConvert.SerializeObject(uploadUrlResponseBody);
                var httpContent = new StringContent(json, System.Text.Encoding.UTF8, "application/json");
                var alternativeFileUrlWithId = string.Format(UploadAlternativeFileUrl, entityId);
                var uploadAlternativeFileResponse = await client.PostAsync($"{AppSettings.Host}{alternativeFileUrlWithId}", httpContent);
                uploadAlternativeFileResponse.EnsureSuccessStatusCode();
                var uploadAlternativeFileResponseBody = JObject.Parse(await uploadAlternativeFileResponse.Content.ReadAsStringAsync());
                _logger.LogDebug($"Upload alternative file request has been sent. Response status is: {uploadAlternativeFileResponse.StatusCode}");
                _logger.LogInformation($"Upload alternative file is finished.\nResponse is: {uploadAlternativeFileResponseBody}");
            }
            catch (Exception e)
            {
                _logger.LogError($"Error during alternative file update. Exception: {e.Message}");
                _logger.LogError($"{e.StackTrace}");
            }
        }

        private HttpRequestMessage GetUploadUrlRequestMessage()
        {
            var uploadUrlRequest = new HttpRequestMessage(HttpMethod.Post, $"{AppSettings.Host}{RequestUploadUrl}");            
            uploadUrlRequest.Content = new FormUrlEncodedContent(new Dictionary<string, string>
            {
                { "fileName", _fileName },
                { "fileSize", _fileSize }
            });
            return uploadUrlRequest;
        }
    }
}