using System.Net;

namespace AMWD.Common.Tests.Extensions
{
	[TestClass]
	public class IPAddressExtensionsTest
	{
		[TestMethod]
		public void ShouldIncrementLastByte()
		{
			// arrange
			var ipAddress = IPAddress.Parse("192.168.178.22");

			// act
			var incremented = ipAddress.Increment();

			// assert
			Assert.AreEqual("192.168.178.23", incremented.ToString());
		}

		[TestMethod]
		public void ShouldIncrementAllBytes()
		{
			// arrange
			var ipAddress = IPAddress.Parse("192.255.255.255");

			// act
			var incremented = ipAddress.Increment();

			// assert
			Assert.AreEqual("193.0.0.0", incremented.ToString());
		}

		[TestMethod]
		public void ShouldIncrementOverflow()
		{
			// arrange
			var ipAddress = IPAddress.Parse("255.255.255.255");

			// act
			var incremented = ipAddress.Increment();

			// assert
			Assert.AreEqual("0.0.0.0", incremented.ToString());
		}

		[TestMethod]
		public void ShouldDecrementLastByte()
		{
			// arrange
			var ipAddress = IPAddress.Parse("192.168.178.22");

			// act
			var decremented = ipAddress.Decrement();

			// assert
			Assert.AreEqual("192.168.178.21", decremented.ToString());
		}

		[TestMethod]
		public void ShouldDecrementAllBytes()
		{
			// arrange
			var ipAddress = IPAddress.Parse("192.0.0.0");

			// act
			var decremented = ipAddress.Decrement();

			// assert
			Assert.AreEqual("191.255.255.255", decremented.ToString());
		}

		[TestMethod]
		public void ShouldDecrementUnderflow()
		{
			// arrange
			var ipAddress = IPAddress.Parse("0.0.0.0");

			// act
			var decremented = ipAddress.Decrement();

			// assert
			Assert.AreEqual("255.255.255.255", decremented.ToString());
		}
	}
}