//Controller
[HttpPost]
[DisableRequestSizeLimit]
[Route("Register")]
public async Task<IActionResult> Register([FromForm] UserViewModel uvm)
{
    try
    {
        var formCollection = await Request.ReadFormAsync();

        // Retrieves the first file from the form data, which is expected to be the user's photo.
        var photo = formCollection.Files.FirstOrDefault();

        // Attempts to find an existing user by the provided email.
        var user = await _userManager.FindByEmailAsync(uvm.Email);

        // If the user is not found, proceed with registration.
        if (user == null)
        {
            // Uses a memory stream to process the photo file.
            using (var memoryStream = new MemoryStream())
            {
                // Copies the photo file data into the memory stream asynchronously.
                await photo.CopyToAsync(memoryStream);

                // Converts the memory stream data into a byte array.
                var fileBytes = memoryStream.ToArray();

                // Encodes the byte array to a base64 string.
                string base64Image = Convert.ToBase64String(fileBytes);

                // Creates a new user object with the provided details and hashed password.
                user = new User
                {
                    UserName = uvm.Email,
                    Email = uvm.Email,
                    PasswordHash = _userManager.PasswordHasher.HashPassword(null, uvm.Password),
                    Photo = base64Image // Stores the base64 string in the user's profile.
                };

                // Attempts to create the new user asynchronously.
                IdentityResult result = await _userManager.CreateAsync(user);

                // If the user creation is successful, return a success response.
                if (result.Succeeded)
                {
                    return Ok(new { Status = "Success", Message = "User created successfully!" });
                }
                // If user creation fails, return an error response with the first error message.
                else
                {
                    return StatusCode(StatusCodes.Status500InternalServerError, result.Errors.FirstOrDefault()?.Description);
                }
            }
        }
        // If the user already exists, return a forbidden response.
        else
        {
            return Forbid("Account already exists.");
        }
    }
    catch (Exception ex)
    {
        // If an exception occurs, return a generic error response.
        return StatusCode(StatusCodes.Status500InternalServerError, "An error occurred while processing your request.");
    }
}

//program cs
// Configure FormOptions for file uploads
builder.Services.Configure<FormOptions>(o =>
{
    o.ValueLengthLimit = int.MaxValue;
    o.MultipartBodyLengthLimit = int.MaxValue;
    o.MemoryBufferThreshold = int.MaxValue;
});