using System.Security.Cryptography;
using System.Text;

namespace Connected.Security.Cryptography
{
	internal class CryptographyService : ICryptographyService
	{
		public byte[]? Hash(string value)
		{
			if (string.IsNullOrEmpty(value))
				return null;

			using var md = MD5.Create();

			return GetHash(md, value);
		}

		private static byte[] GetHash(MD5 hash, string value)
		{
			return hash.ComputeHash(Encoding.UTF8.GetBytes(value));
		}

		public bool Verify(string value, byte[] existing)
		{
			if (value is null && existing is null)
				return false;

			if (!value.Any() && !existing.Any())
				return false;

			using var md = MD5.Create();

			var hash = GetHash(md, value);

			if (value.Length != hash.Length)
				return false;

			for (var i = 0; i < value.Length; i++)
			{
				if (value[i] != hash[i])
					return false;
			}

			return true;
		}
	}
}