ImageHelper.cs

// Part Of SmartTech.NGOIPPF.Application
// All rights reserved © 2021  AlBannaTechno(OsamaAlBanna)

using System.Drawing;
using System.Drawing.Imaging;
using System.IO;

namespace SmartTech.NGOIPPF.Helper
{
    /// <summary>
    /// some image non related helpers
    /// <b>this class should only tested with unit test</b>
    /// </summary>
    public static class ImageHelper
    {
        /// <summary>
        /// <b>be aware of the performance of this method, since this will firstly convert
        /// the byte array to image</b>
        /// </summary>
        /// <param name="arr"></param>
        /// <returns></returns>
        public static string GetExtension(byte[] arr)
        {
            var img = ByteArrayToImage(arr);
            if (Equals(img.RawFormat, ImageFormat.Png))
            {
                return nameof(ImageFormat.Png);
            }
            if (Equals(img.RawFormat, ImageFormat.Jpeg))
            {
                return nameof(ImageFormat.Jpeg);
            }
            if (Equals(img.RawFormat, ImageFormat.Gif))
            {
                return nameof(ImageFormat.Gif);
            }
            return null;
        }
        
        public static Image ByteArrayToImage( byte[] bmpBytes )
        {
            Image image = null;
            using( MemoryStream stream = new MemoryStream( bmpBytes ) )
            {
                image = Image.FromStream( stream );
            }

            return image;
        }
    }
}

ProfileAppService.cs

        /// <summary>
        /// Update user profile with the next  cases
        /// * Update username
        /// * Update email
        /// * Update Image: image file can be both base64 or link
        /// * link, should exist as it
        /// * base64 should decrypted back to the original file, then uploaded to the server
        /// </summary>
        /// <param name="profile"></param>
        public async Task UpdateProfile(UpdateProfileInput profile)
        {
            var user = await UserManager.FindByNameAsync(profile.Name);
            if (user == null) { return; }
            var result = UploadProfileImageToLocalStorage(profile.Image, user.Id);

            if (result.isLink)
            {
                // ?
            }
            
            var attachment = new CreateOrEditAttachmentDto
            {
                Extension = result.ext,
                FileName = result.filename,
                FilePath = result.filepath,
                ObjectType = ObjectTypeEnum.UserProfileImage,
                // TODO: check this || invalid conversion || try to parse
                ObjectTypeId = user.TenantId,
                // specified from the team, must be with the same value in the first seeding
                AttachmentTypeId = 2,
                CreatedOn = DateTime.Now
            };
            await _attachmentsAppService.CreateOrEdit(attachment);

            // ?
            user.ProfilePictureId = attachment.Id;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="file"></param>
        /// <param name="id"></param>
        /// <returns>Extension extracted from metadata</returns>
        private (string filename, string filepath, string ext, bool isLink) UploadProfileImageToLocalStorage(string file, long id)
        {
            if (file.StartsWith("http"))
            {
                return (file, file, null, true);
            }
            
            // TODO: must test this logic
            var base64 = file.Substring(file.IndexOf(',') + 1);
            var data = Convert.FromBase64String(base64);
            // TODO: this method should replaced due to high CPU costs
            var ext = ImageHelper.GetExtension(data);
            var filename = $"{DateTime.Now.Millisecond.ToString()}.{ext}";
            var filePath = $"attachment\\{ObjectTypeEnum.UserProfileImage}\\{id}\\{filename}";
            File.WriteAllBytes($"{_environment.WebRootPath}\\{filePath}", data);
            filePath = _configurationRoot["App:ServerRootAddress"] + filePath.Replace('\\', '/');
            return (filename, filePath, ext, false);
        }

UpdateProfileInput.cs

// Part Of SmartTech.NGOIPPF.Application.Shared

using System.ComponentModel.DataAnnotations;
using Abp.Authorization.Users;

namespace SmartTech.NGOIPPF.Authorization.Users.Profile.Dto
{
    public class UpdateProfileInput
    {
        [Required]
        [StringLength(UserConsts.MaxPhoneNumberLength)]
        public string PhoneNumber { get; set; }
        
        [Required]
        [StringLength(AbpUserBase.MaxNameLength)]
        public string Name { get; set; }
        
        [StringLength(AbpUserBase.MaxEmailAddressLength)]
        public string Email { get; set; }
        public string Image { get; set; }
    }
}