using System.Text;
using Microsoft.AspNetCore.Http;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Moq;
using Newtonsoft.Json;

namespace UnitTests.AspNetCore.Extensions
{
	[TestClass]
	[System.Diagnostics.CodeAnalysis.ExcludeFromCodeCoverage]
	public class SessionExtensionsTests
	{
		private Mock<ISession> sessionMock;

		private string sessionKey;
		private byte[] sessionValue;

		private TestModel model;

		internal class TestModel
		{
			public string ValueA { get; set; }

			public string ValueB { get; set; }
		}

		[TestInitialize]
		public void InitializeTests()
		{
			sessionKey = null;
			sessionValue = null;

			model = new TestModel
			{
				ValueA = "A",
				ValueB = "B"
			};
		}

		[TestMethod]
		public void ShouldCheckKeyExists()
		{
			// arrange
			sessionKey = "exists";
			var session = GetSession();

			// act
			bool result1 = session.HasKey("exists");
			bool result2 = session.HasKey("somewhere");

			// assert
			Assert.IsTrue(result1);
			Assert.IsFalse(result2);
		}

		[TestMethod]
		public void ShouldGetValue()
		{
			// arrange
			sessionKey = "test";
			sessionValue = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(model));
			var session = GetSession();

			// act
			var result = session.GetValue<TestModel>(sessionKey);

			// assert
			Assert.IsNotNull(result);
			Assert.AreEqual(model.ValueA, result.ValueA);
			Assert.AreEqual(model.ValueB, result.ValueB);
		}

		[TestMethod]
		public void ShouldGetNull()
		{
			// arrange
			sessionKey = "foo";
			sessionValue = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(model));
			var session = GetSession();

			// act
			var result = session.GetValue<TestModel>("bar");

			// assert
			Assert.IsNull(result);
		}

		[TestMethod]
		public void ShouldGetValueWithFallback()
		{
			// arrange
			sessionKey = "test";
			sessionValue = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(model));
			var session = GetSession();

			// act
			var result = session.GetValue(sessionKey, new TestModel());

			// assert
			Assert.IsNotNull(result);
			Assert.AreEqual(model.ValueA, result.ValueA);
			Assert.AreEqual(model.ValueB, result.ValueB);
		}

		[TestMethod]
		public void ShouldGetFallback()
		{
			// arrange
			sessionKey = "foo";
			sessionValue = Encoding.UTF8.GetBytes(JsonConvert.SerializeObject(model));
			var session = GetSession();

			// act
			var result = session.GetValue("bar", new TestModel());

			// assert
			Assert.IsNotNull(result);
			Assert.AreEqual(null, result.ValueA);
			Assert.AreEqual(null, result.ValueB);
		}

		[TestMethod]
		public void ShouldSetValue()
		{
			// arrange
			string key = "foobar";
			var session = GetSession();

			// act
			session.SetValue(key, model);

			// arrange
			Assert.AreEqual(key, sessionKey);
			Assert.AreEqual(JsonConvert.SerializeObject(model), Encoding.UTF8.GetString(sessionValue));
		}

		private ISession GetSession()
		{
			string[] keys = new[] { sessionKey };

			sessionMock = new Mock<ISession>();
			sessionMock
				.Setup(s => s.TryGetValue(It.IsAny<string>(), out sessionValue))
				.Returns<string, byte[]>((key, value) => sessionKey == key);
			sessionMock
				.Setup(s => s.Set(It.IsAny<string>(), It.IsAny<byte[]>()))
				.Callback<string, byte[]>((key, value) =>
				{
					sessionKey = key;
					sessionValue = value;
				});
			sessionMock
				.Setup(s => s.Keys)
				.Returns(keys);

			return sessionMock.Object;
		}
	}
}