// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using System;

namespace Microsoft.Extensions.Options
{
    /// <summary>
    /// Implementation of <see cref="IConfigureOptions{TOptions}"/>.
    /// </summary>
    /// <typeparam name="TOptions">Options type being configured.</typeparam>
    public class ConfigureOptions<TOptions> : IConfigureOptions<TOptions> where TOptions : class
    {
        /// <summary>
        /// Initializes a new instance of <see cref="ConfigureOptions{TOptions}"/>.
        /// </summary>
        /// <param name="action">The action to register.</param>
        public ConfigureOptions(Action<TOptions>? action)
        {
            Action = action;
        }

        /// <summary>
        /// Gets the configuration action.
        /// </summary>
        public Action<TOptions>? Action { get; }

        /// <summary>
        /// Invokes the registered configure <see cref="Action"/>.
        /// </summary>
        /// <param name="options">The options instance to configure.</param>
        public virtual void Configure(TOptions options)
        {
            ArgumentNullException.ThrowIfNull(options);

            Action?.Invoke(options);
        }
    }
}