From 5b96a6c0ab5610ba6ebb4a23f4c8562e96dadced Mon Sep 17 00:00:00 2001
From: Jericho <desautelsj@hotmail.com>
Date: Thu, 28 Jan 2021 15:51:29 -0500
Subject: [PATCH] (GH-368) Add missing 'limit' and 'offset' parameters to
 IpAddresses.GetUnassignedAsync

---
 .../Tests/IpAddresses.cs                      |  2 +-
 Source/StrongGrid/Extensions/Public.cs        | 25 ++++++++++++++-----
 Source/StrongGrid/Utilities/Utils.cs          |  4 +++
 3 files changed, 24 insertions(+), 7 deletions(-)

diff --git a/Source/StrongGrid.IntegrationTests/Tests/IpAddresses.cs b/Source/StrongGrid.IntegrationTests/Tests/IpAddresses.cs
index 6f0009f2..a5590afc 100644
--- a/Source/StrongGrid.IntegrationTests/Tests/IpAddresses.cs
+++ b/Source/StrongGrid.IntegrationTests/Tests/IpAddresses.cs
@@ -40,7 +40,7 @@ public async Task RunAsync(IBaseClient client, TextWriter log, CancellationToken
 			await log.WriteLineAsync($"There are {assigned.Length} assigned IP addresses").ConfigureAwait(false);
 
 			// GET THE UNASSIGNED IP ADDRESSES
-			var unAssigned = await client.IpAddresses.GetUnassignedAsync(cancellationToken).ConfigureAwait(false);
+			var unAssigned = await client.IpAddresses.GetUnassignedAsync(cancellationToken: cancellationToken).ConfigureAwait(false);
 			await log.WriteLineAsync($"There are {unAssigned.Length} unassigned IP addresses").ConfigureAwait(false);
 
 			// GET THE REMAINING IP ADDRESSES
diff --git a/Source/StrongGrid/Extensions/Public.cs b/Source/StrongGrid/Extensions/Public.cs
index e2f6d6c5..1f7c6fb1 100644
--- a/Source/StrongGrid/Extensions/Public.cs
+++ b/Source/StrongGrid/Extensions/Public.cs
@@ -1130,19 +1130,32 @@ public static Task<Segment> UpdateAsync(this ISegments segments, string segmentI
 		/// Retrieve unassigned IP addresses.
 		/// </summary>
 		/// <param name="ipAddresses">The IP addresses resource.</param>
+		/// <param name="limit">The number of IPs you want returned at the same time.</param>
+		/// <param name="offset">The offset for the number of IPs that you are requesting.</param>
 		/// <param name="cancellationToken">Cancellation token.</param>
 		/// <returns>
 		/// An array of <see cref="IpAddress">Ip addresses</see>.
 		/// </returns>
-		public static async Task<IpAddress[]> GetUnassignedAsync(this IIpAddresses ipAddresses, CancellationToken cancellationToken = default)
+		public static async Task<IpAddress[]> GetUnassignedAsync(this IIpAddresses ipAddresses, int limit = 10, int offset = 0, CancellationToken cancellationToken = default)
 		{
-			var allIpAddresses = await ipAddresses.GetAllAsync(cancellationToken: cancellationToken).ConfigureAwait(false);
+			var unassignedIpAddresses = new List<IpAddress>(limit);
+			var currentOffset = 0;
 
-			var unassignedIpAddresses = allIpAddresses.Records
-				.Where(ip => ip.Pools == null || !ip.Pools.Any())
-				.ToArray();
+			while (true)
+			{
+				var allIpAddresses = await ipAddresses.GetAllAsync(limit: Utils.MaxSendGridPagingLimit, offset: currentOffset, cancellationToken: cancellationToken).ConfigureAwait(false);
+				unassignedIpAddresses.AddRange(allIpAddresses.Records.Where(ip => ip.Pools == null || !ip.Pools.Any()));
+
+				if (unassignedIpAddresses.Count >= offset + limit) break;
+				if (allIpAddresses.Next == null) break;
 
-			return unassignedIpAddresses;
+				currentOffset += Utils.MaxSendGridPagingLimit;
+			}
+
+			return unassignedIpAddresses
+				.Skip(offset)
+				.Take(limit)
+				.ToArray();
 		}
 
 	}
diff --git a/Source/StrongGrid/Utilities/Utils.cs b/Source/StrongGrid/Utilities/Utils.cs
index 88a05a84..0b113cec 100644
--- a/Source/StrongGrid/Utilities/Utils.cs
+++ b/Source/StrongGrid/Utilities/Utils.cs
@@ -11,6 +11,10 @@ internal static class Utils
 	{
 		private static readonly byte[] Secp256R1Prefix = Convert.FromBase64String("MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAE");
 
+		public const int MaxSendGridPagingLimit = 500;
+
+		public static DateTime Epoch { get; } = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
+
 		public static RecyclableMemoryStreamManager MemoryStreamManager { get; } = new RecyclableMemoryStreamManager();
 
 		/// <summary>