// Copyright (c) Six Labors.
// Licensed under the Six Labors Split License.

using System;

namespace SixLabors.ImageSharp.Drawing.Helpers {
  /// <summary>
  /// Extension methods for arrays.
  /// </summary>
  internal static class ArrayExtensions
  {
      /// <summary>
      /// Concatenates two arrays into one.
      /// </summary>
      /// <typeparam name="T">The element type.</typeparam>
      /// <param name="source1">The first source array.</param>
      /// <param name="source2">The second source array.</param>
      /// <returns>
      /// A new array containing the elements of both source arrays, or <paramref name="source1"/>
      /// when <paramref name="source2"/> is empty.
      /// </returns>
      public static T[] Concat<T>(this T[] source1, T[] source2)
      {
          if (source2 is null || source2.Length == 0)
          {
              return source1;
          }

          T[] target = new T[source1.Length + source2.Length];
          source1.AsSpan().CopyTo(target);
          source2.AsSpan().CopyTo(target.AsSpan(source1.Length));

          return target;
      }
  }
}