using System;
using System.Collections.Generic;
using System.Net;
using Microsoft.AspNetCore.Antiforgery;
using Microsoft.AspNetCore.Http;
using Microsoft.VisualStudio.TestTools.UnitTesting;
using Moq;

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

		private string tokenName;
		private string tokenValue;

		private Dictionary<string, string> requestHeaders;
		private Dictionary<string, string> requestQueries;
		private Dictionary<object, object> items;

		private IPAddress remote;

		[TestInitialize]
		public void InitializeTests()
		{
			tokenName = null;
			tokenValue = null;

			requestHeaders = new Dictionary<string, string>();
			requestQueries = new Dictionary<string, string>();
			items = new Dictionary<object, object>();

			remote = IPAddress.Loopback;
		}

		#region Antiforgery

		[TestMethod]
		public void ShouldReturnAntiforgery()
		{
			// arrange
			tokenName = "af-token";
			tokenValue = "security_first";

			var context = GetContext();

			// act
			var result = context.GetAntiforgeryToken();

			// assert
			Assert.AreEqual(tokenName, result.Name);
			Assert.AreEqual(tokenValue, result.Value);
		}

		[TestMethod]
		public void ShouldReturnAntiforgeryNullService()
		{
			// arrange
			tokenName = "af-token";
			tokenValue = "security_first";

			var context = GetContext(hasAntiforgery: false);

			// act
			var result = context.GetAntiforgeryToken();

			// assert
			Assert.AreEqual(null, result.Name);
			Assert.AreEqual(null, result.Value);
		}

		[TestMethod]
		public void ShouldReturnAntiforgeryNullToken()
		{
			// arrange
			var context = GetContext();

			// act
			var result = context.GetAntiforgeryToken();

			// assert
			Assert.AreEqual(null, result.Name);
			Assert.AreEqual(null, result.Value);
		}

		#endregion Antiforgery

		#region RemoteAddres

		[TestMethod]
		public void ShouldReturnRemoteAddress()
		{
			// arrange
			remote = IPAddress.Parse("1.2.3.4");

			var context = GetContext();

			// act
			var result = context.GetRemoteIpAddress();

			// assert
			Assert.AreEqual(remote, result);
		}

		[TestMethod]
		public void ShouldReturnDefaultHeader()
		{
			// arrange
			remote = IPAddress.Parse("1.2.3.4");
			var header = IPAddress.Parse("5.6.7.8");
			requestHeaders.Add("X-Forwarded-For", header.ToString());

			var context = GetContext();

			// act
			var result = context.GetRemoteIpAddress();

			// assert
			Assert.AreNotEqual(remote, result);
			Assert.AreEqual(header, result);
		}

		[TestMethod]
		public void ShouldReturnCustomHeader()
		{
			// arrange
			remote = IPAddress.Parse("1.2.3.4");
			string headerName = "FooBar";
			var headerIp = IPAddress.Parse("5.6.7.8");
			requestHeaders.Add(headerName, headerIp.ToString());

			var context = GetContext();

			// act
			var result = context.GetRemoteIpAddress(headerName: headerName);

			// assert
			Assert.AreNotEqual(remote, result);
			Assert.AreEqual(headerIp, result);
		}

		[TestMethod]
		public void ShouldReturnAddressInvalidHeader()
		{
			// arrange
			remote = IPAddress.Parse("1.2.3.4");
			requestHeaders.Add("X-Forwarded-For", "1.2.3:4");

			var context = GetContext();

			// act
			var result = context.GetRemoteIpAddress();

			// assert
			Assert.AreEqual(remote, result);
		}

		#endregion RemoteAddres

		#region Local Request

		[TestMethod]
		public void ShouldReturnTrueOnLocal()
		{
			// arrange
			remote = IPAddress.Loopback;

			var context = GetContext();

			// act
			bool result = context.IsLocalRequest();

			// assert
			Assert.IsTrue(result);
		}

		[TestMethod]
		public void ShouldReturnFalseOnRemote()
		{
			// arrange
			remote = IPAddress.Parse("1.2.3.4");

			var context = GetContext();

			// act
			bool result = context.IsLocalRequest();

			// assert
			Assert.IsFalse(result);
		}

		[TestMethod]
		public void ShouldReturnTrueOnDefaultHeader()
		{
			// arrange
			remote = IPAddress.Parse("1.2.3.4");
			var headerIp = IPAddress.Loopback;
			requestHeaders.Add("X-Forwarded-For", headerIp.ToString());

			var context = GetContext();

			// act
			bool result = context.IsLocalRequest();

			// assert
			Assert.IsTrue(result);
		}

		[TestMethod]
		public void ShouldReturnTrueOnCustomHeader()
		{
			// arrange
			remote = IPAddress.Parse("1.2.3.4");
			string headerName = "FooBar";
			var headerIp = IPAddress.Loopback;
			requestHeaders.Add(headerName, headerIp.ToString());

			var context = GetContext();

			// act
			bool result = context.IsLocalRequest(headerName: headerName);

			// assert
			Assert.IsTrue(result);
		}

		[TestMethod]
		public void ShouldReturnFalseOnDefaultHeader()
		{
			// arrange
			var headerIp = IPAddress.Parse("1.2.3.4");
			requestHeaders.Add("X-Forwarded-For", headerIp.ToString());

			var context = GetContext();

			// act
			bool result = context.IsLocalRequest();

			// assert
			Assert.IsFalse(result);
		}

		[TestMethod]
		public void ShouldReturnFalseOnCustomHeader()
		{
			// arrange
			string headerName = "FooBar";
			var headerIp = IPAddress.Parse("1.2.3.4");
			requestHeaders.Add(headerName, headerIp.ToString());

			var context = GetContext();

			// act
			bool result = context.IsLocalRequest(headerName: headerName);

			// assert
			Assert.IsFalse(result);
		}

		#endregion Local Request

		#region ReturnUrl

		[TestMethod]
		public void ShouldReturnNull()
		{
			// arrange
			var context = GetContext();

			// act
			string result = context.GetReturnUrl();

			// assert
			Assert.IsNull(result);
		}

		[TestMethod]
		public void ShouldReturnOriginalRequest()
		{
			// arrange
			string request = "abc";
			string query = "def";

			items.Add("OriginalRequest", request);
			requestQueries.Add("ReturnUrl", query);

			var context = GetContext();

			// act
			string result = context.GetReturnUrl();

			// assert
			Assert.AreEqual(request, result);
			Assert.AreNotEqual(query, result);
		}

		[TestMethod]
		public void ShouldReturnUrl()
		{
			// arrange
			string query = "def";
			requestQueries.Add("ReturnUrl", query);

			var context = GetContext();

			// act
			string result = context.GetReturnUrl();

			// assert
			Assert.AreEqual(query, result);
		}

		#endregion ReturnUrl

		#region Session

		[TestMethod]
		public void ShouldClearSession()
		{
			// arrange
			var context = GetContext();

			// act
			context.ClearSession();

			// assert
			sessionMock.Verify(s => s.Clear(), Times.Once);
		}

		[TestMethod]
		public void ShouldSkipWhenNoSession()
		{
			// arrange
			var context = GetContext(hasSession: false);

			// act
			context.ClearSession();

			// assert
			sessionMock.Verify(s => s.Clear(), Times.Never);
		}

		#endregion Session

		private HttpContext GetContext(bool hasAntiforgery = true, bool hasSession = true)
		{
			// Request
			var requestHeaderMock = new Mock<IHeaderDictionary>();
			foreach (var header in requestHeaders)
			{
				requestHeaderMock
					.Setup(h => h.ContainsKey(header.Key))
					.Returns(true);
				requestHeaderMock
					.Setup(h => h[header.Key])
					.Returns(header.Value);
			}

			var requestQueryMock = new Mock<IQueryCollection>();
			foreach (var query in requestQueries)
			{
				requestQueryMock
					.Setup(h => h.ContainsKey(query.Key))
					.Returns(true);
				requestQueryMock
					.Setup(h => h[query.Key])
					.Returns(query.Value);
			}

			var requestMock = new Mock<HttpRequest>();
			requestMock
				.Setup(r => r.Headers)
				.Returns(requestHeaderMock.Object);
			requestMock
				.Setup(r => r.Query)
				.Returns(requestQueryMock.Object);

			// Request Services
			var requestServicesMock = new Mock<IServiceProvider>();
			if (hasAntiforgery)
			{
				var antiforgeryMock = new Mock<IAntiforgery>();
				antiforgeryMock
					.Setup(af => af.GetAndStoreTokens(It.IsAny<HttpContext>()))
					.Returns(string.IsNullOrWhiteSpace(tokenName) ? null : new AntiforgeryTokenSet(tokenValue, tokenValue, tokenName, tokenName));

				requestServicesMock
					.Setup(rs => rs.GetService(typeof(IAntiforgery)))
					.Returns(antiforgeryMock.Object);
			}

			// Connection
			var connectionInfoMock = new Mock<ConnectionInfo>();
			connectionInfoMock
				.Setup(ci => ci.LocalIpAddress)
				.Returns(IPAddress.Loopback);
			connectionInfoMock
				.Setup(ci => ci.RemoteIpAddress)
				.Returns(remote);

			// Session
			sessionMock = new Mock<ISession>();

			var contextMock = new Mock<HttpContext>();
			contextMock
				.Setup(c => c.Request)
				.Returns(requestMock.Object);
			contextMock
				.Setup(c => c.RequestServices)
				.Returns(requestServicesMock.Object);
			contextMock
				.Setup(c => c.Connection)
				.Returns(connectionInfoMock.Object);
			contextMock
				.Setup(c => c.Items)
				.Returns(items);
			if (hasSession)
			{
				contextMock
					.Setup(c => c.Session)
					.Returns(sessionMock.Object);
			}

			return contextMock.Object;
		}
	}
}