[HttpPost]
        public async Task<ActionResult<ProductOwner>> PostProductOwner(ProductOwner productOwner)
        {
          if (_context.ProductOwners == null)
          {
              return Problem("Entity set 'ApplicationDbContext.ProductOwners'  is null.");
          }

            // Configure warranty expiration date and status
            var warrantyDetail = new WarrantyDetail
            {
                ExpirationDate = DateTime.Now.AddYears(2).Date,
                WarrantyStatus = "Active",
            };


            productOwner.ProductSerialNumber = await GenerateUniqueSerialNumberAsync();
            
            // Query ProductDetail
            var productDetail = await _context.ProductDetails.FirstOrDefaultAsync(pd => pd.ProductDetailId == productOwner.ProductDetailId);

            if (productDetail == null) { 
                return BadRequest();
            }
            
            
            var newProductOwner = new ProductOwner
            {
                OwnerFirstName = productOwner.OwnerFirstName,
                OwnerLastName = productOwner.OwnerLastName,
                EmailAddress = productOwner.EmailAddress,
                PhoneNum = productOwner.PhoneNum,
                ProductSerialNumber = productOwner.ProductSerialNumber,
                ProductDetailId = productOwner.ProductDetailId,
                ProductDetail = productDetail,
                WarrantyDetail = warrantyDetail
            };

            // Setting the reverse navigation property
            warrantyDetail.ProductOwner = newProductOwner;
            productDetail.ProductOwners.Add(newProductOwner);

            _context.ProductOwners.Add(newProductOwner);
            await _context.SaveChangesAsync();

            return Ok(await _context.ProductOwners.ToListAsync());
        }

[HttpPost]
        public async Task<ActionResult<ProductOwner>> PostProductOwner(ProductOwner productOwner)
        {
          if (_context.ProductOwners == null)
          {
              return Problem("Entity set 'ApplicationDbContext.ProductOwners'  is null.");
          }

            // Configure warranty expiration date and status
            var warrantyDetail = new WarrantyDetail
            {
                ExpirationDate = DateTime.Now.AddYears(2).Date,
                WarrantyStatus = "Active",
            };


            productOwner.ProductSerialNumber = await GenerateUniqueSerialNumberAsync();
            
            // Query ProductDetail
            var productDetail = await _context.ProductDetails.FirstOrDefaultAsync(pd => pd.ProductDetailId == productOwner.ProductDetailId);

            if (productDetail == null) { 
                return BadRequest();
            }
            
            
            var newProductOwner = new ProductOwner
            {
                OwnerFirstName = productOwner.OwnerFirstName,
                OwnerLastName = productOwner.OwnerLastName,
                EmailAddress = productOwner.EmailAddress,
                PhoneNum = productOwner.PhoneNum,
                ProductSerialNumber = productOwner.ProductSerialNumber,
                ProductDetailId = productOwner.ProductDetailId,
                ProductDetail = productDetail,
                WarrantyDetail = warrantyDetail
            };

            // Setting the reverse navigation property
            warrantyDetail.ProductOwner = newProductOwner;
            productDetail.ProductOwners.Add(newProductOwner);

            _context.ProductOwners.Add(newProductOwner);
            await _context.SaveChangesAsync();

            return Ok(await _context.ProductOwners.ToListAsync());
        }

 public ProductOwner? ProductOwner 

 public ProductOwner? ProductOwner 

public class WarrantyDetail
    {
        [Key]
        public int WarrantyDetailId { get; set; }
        [DisplayFormat(DataFormatString = "{0:dd:MM:yyyy}", ApplyFormatInEditMode = true)]
        public DateTime ExpirationDate { get; set; }
        public string WarrantyStatus { get; set; } = "";
        public ProductOwner? ProductOwner { get; set; }

    }

public class WarrantyDetail
    {
        [Key]
        public int WarrantyDetailId { get; set; }
        [DisplayFormat(DataFormatString = "{0:dd:MM:yyyy}", ApplyFormatInEditMode = true)]
        public DateTime ExpirationDate { get; set; }
        public string WarrantyStatus { get; set; } = "";
        public ProductOwner? ProductOwner { get; set; }

    }