using Unity.Collections;

namespace Unity.XR.CoreUtils
{
    /// <summary>
    /// Utility methods for working with <see cref="NativeArray{T}"/> objects.
    /// </summary>
    public static class NativeArrayUtils
    {
        /// <summary>
        /// Ensure that this array is large enough to contain the given capacity.
        /// </summary>
        /// <remarks>
        /// If the array does not have sufficient capacity, it is disposed and a new, empty array is created.
        /// </remarks>
        /// <typeparam name="T">The type of array element.</typeparam>
        /// <param name="array">The array reference. Overwritten if the original array has insufficient capacity.</param>
        /// <param name="capacity">The minimum number of elements that the array must be able to contain.</param>
        /// <param name="allocator">The allocator to use when creating a new array, if needed.</param>
        /// <param name="options">The options to use when creating the new array, if needed.</param>
        public static void EnsureCapacity<T>(ref NativeArray<T> array, int capacity, Allocator allocator, NativeArrayOptions options = NativeArrayOptions.ClearMemory) where T : struct
        {
            if (array.Length < capacity)
            {
                if (array.IsCreated)
                {
                    array.Dispose();
                }

                array = new NativeArray<T>(capacity, allocator, options);
            }
        }
    }
}