From 43fd348fae4e150570eef1214a81215899a45718 Mon Sep 17 00:00:00 2001
From: Austin Noska <austin.noska@profound-tech.com>
Date: Tue, 13 Apr 2021 12:09:31 -0400
Subject: [PATCH] feat: Add enum extension method for cycling to next enum
 value

---
 CHANGELOG.md                                  |  1 +
 .../Extensions/EnumExtensionsTest.cs          | 12 ++++++++++
 ICD.Common.Utils/Extensions/EnumExtensions.cs | 22 +++++++++++++++++++
 ICD.Common.Utils/Extensions/ListExtensions.cs | 16 ++++++++++++++
 4 files changed, 51 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f2b11fe..c7a1d62 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 
 ## [Unreleased]
 ### Added
+ - Added enum extension method for cycling to the next enum value
  - Added GetLocalTimeZoneName method to IcdEnvironment
  - Added MatchAny method to RegexUtils
  - Added OnSystemDeviceAddedRemoved and associated raise methods to IcdEnvironment for NETSTANDARD
diff --git a/ICD.Common.Utils.Tests/Extensions/EnumExtensionsTest.cs b/ICD.Common.Utils.Tests/Extensions/EnumExtensionsTest.cs
index d81f22c..0b94167 100644
--- a/ICD.Common.Utils.Tests/Extensions/EnumExtensionsTest.cs
+++ b/ICD.Common.Utils.Tests/Extensions/EnumExtensionsTest.cs
@@ -32,5 +32,17 @@ namespace ICD.Common.Utils.Tests.Extensions
 		{
 			Assert.AreEqual(expected, value.HasFlags(flags));
 		}
+
+		[TestCase(eTestEnum.A, eTestEnum.B)]
+		[TestCase(eTestEnum.B, eTestEnum.C)]
+		[TestCase(eTestEnum.C, eTestEnum.A)]
+		[TestCase(eTestEnum.A | eTestEnum.B, null)]
+		public void CycleNextTest(eTestEnum value, eTestEnum? expected)
+		{
+			if (EnumUtils.HasMultipleFlags(value))
+				Assert.Catch(typeof(InvalidOperationException), () => value.CycleNext());
+			else
+				Assert.AreEqual(expected, value.CycleNext());
+		}
 	}
 }
diff --git a/ICD.Common.Utils/Extensions/EnumExtensions.cs b/ICD.Common.Utils/Extensions/EnumExtensions.cs
index 559bb7c..fbbb9d0 100644
--- a/ICD.Common.Utils/Extensions/EnumExtensions.cs
+++ b/ICD.Common.Utils/Extensions/EnumExtensions.cs
@@ -1,4 +1,6 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
 using ICD.Common.Properties;
 
 namespace ICD.Common.Utils.Extensions
@@ -83,5 +85,25 @@ namespace ICD.Common.Utils.Extensions
 		{
 			return EnumUtils.ToStringUndefined(extends);
 		}
+
+		/// <summary>
+		/// Returns the next defined enum value for the enum type.
+		/// </summary>
+		/// <typeparam name="T"></typeparam>
+		/// <param name="extends"></param>
+		/// <returns></returns>
+		public static T CycleNext<T>(this T extends)
+			where T : struct, IConvertible
+		{
+			if (EnumUtils.IsFlagsEnum(typeof(T)) && !EnumUtils.HasSingleFlag(extends))
+				throw new InvalidOperationException(string.Format("Cannot cycle enum with multiple flags - {0}", extends));
+
+			IEnumerable<T> values = EnumUtils.GetValues<T>();
+			IList<T> list = values as IList<T> ?? values.ToArray();
+
+			int index = list.BinarySearch(extends);
+
+			return index == list.Count - 1 ? list[0] : list[index + 1];
+		}
 	}
 }
diff --git a/ICD.Common.Utils/Extensions/ListExtensions.cs b/ICD.Common.Utils/Extensions/ListExtensions.cs
index dd41884..5646e17 100644
--- a/ICD.Common.Utils/Extensions/ListExtensions.cs
+++ b/ICD.Common.Utils/Extensions/ListExtensions.cs
@@ -349,6 +349,22 @@ namespace ICD.Common.Utils.Extensions
 
 		#region Binary Search
 
+		/// <summary>
+		/// Returns the index of the item in the list.
+		/// </summary>
+		/// <typeparam name="T"></typeparam>
+		/// <param name="extends"></param>
+		/// <param name="item"></param>
+		/// <returns></returns>
+		[PublicAPI]
+		public static int BinarySearch<T>([NotNull] this IList<T> extends, T item)
+		{
+			if (extends == null)
+				throw new ArgumentNullException("extends");
+
+			return extends.BinarySearch(item, Comparer<T>.Default);
+		}
+
 		/// <summary>
 		/// Returns the index of the item in the list.
 		/// </summary>