using System;
using JD.Kernel.StaticHelpers;

namespace JD.Reflection.Interfaces
{
    /// <summary>
    /// Allows an import that creates an indefinite amount of the exported object.
    /// </summary>
    public class ExportFactory<T>
    {
        #region Variables

        private readonly Func<T> m_creator;

        #endregion

        #region Constructor

        internal ExportFactory(Func<T> creator)
        {
            Throw.IfNull(creator, "creator");
            m_creator = creator;
        }

        #endregion

        #region Methods

        /// <summary>
        /// Creates an instance of the exported object.
        /// </summary>
        /// <returns></returns>
        public T Create()
        {
            return m_creator();
        }

        #endregion
    }

    /// <summary>
    /// Allows an import that creates an indefinite amount of the exported object, with access to metadata.
    /// </summary>
    public class ExportFactory<T, TMetadata> : ExportFactory<T>
    {
        #region Variables

        private readonly TMetadata m_metadata;

        #endregion

        #region Constructor

        internal ExportFactory(Func<T> creator, TMetadata metadata)
            : base(creator)
        {
            m_metadata = metadata;
        }

        #endregion

        #region Properties

        public TMetadata Metadata
        {
            get { return m_metadata; }
        }

        #endregion
    }
}