using JD.Kernel.Classes;
using JD.Kernel.StaticHelpers;

namespace JD.TeaBoxAddinSystem.Addins
{
    /// <summary>
    /// Create a delay between the assignation of a value and its creation. Perfect for lazy loading.
    /// </summary>
    /// <typeparam name="T">Type of its internal value.</typeparam>
    public class ThreadSafeReference<T> : Reference<T>
    {
        #region Variables

        private readonly object m_lock = new object();
        private readonly Provider<T> m_provider;

        #endregion

        #region Constructor/Destructor

        private ThreadSafeReference(Provider<T> provider)
        {
            m_provider = provider;
        }

        public new static ThreadSafeReference<T> FromDelegate(Provider<T> provider)
        {
            return new ThreadSafeReference<T>(provider);
        }

        #endregion

        #region Properties

        public override T Value
        {
            get
            {
                if (!IsInitialized)
                {
                    lock (m_lock)
                    {
                        return base.Value;
                    }
                }

                return base.Value;
            }
        }

        #endregion

        #region Methods

        protected override T LoadValue()
        {
            return m_provider();
        }

        #endregion
    }
}