using System;
using JD.Kernel.Classes;
using JD.Kernel.StaticHelpers;
using JD.Kernel.Structs;
using JD.TeaBoxAddinSystem.Addins.Internal;

namespace JD.TeaBoxAddinSystem.Addins
{
    /// <summary>
    /// Base class for all lazy references.
    /// </summary>
    [LazyReferenceConverter]
    public abstract class LazyReference<T> : Reference<T>, IEquatable<LazyReference<T>>
    {
        #region Variables

        private readonly Node m_node;
        private readonly string m_resourceName;

        #endregion

        #region Constructor

        /// <summary>
        /// Constructor.
        /// </summary>
        /// <param name="node"></param>
        /// <param name="resourcename"></param>
        public LazyReference(Node node, string resourcename)
        {
            Throw.IfNull(node, "node");
            Throw.IfEmpty(resourcename, "resourcename");

            m_node = node;
            m_resourceName = resourcename;
        }

        /// <summary>
        /// Copy constructor.
        /// </summary>
        /// <param name="reference"></param>
        protected LazyReference(LazyReference<T> reference)
        {
            System.Diagnostics.Debug.Assert(reference != null);

            m_node = reference.m_node;
            m_resourceName = reference.m_resourceName;
        }

        #endregion

        #region Properties

        /// <summary>
        /// Gets the file location to log an error.
        /// </summary>
        public string ResourceName
        {
            get { return m_resourceName; }
        }

        /// <summary>
        /// Gets the file location to log an error.
        /// </summary>
        protected FileLocation FileLocation
        {
            get { return m_node.FileLocation; }
        }

        /// <summary>
        /// Gets the node associated with the lazy reference.
        /// </summary>
        protected Node Node
        {
            get { return m_node; }
        }

        #endregion

        #region IEquatable<LazyReference<T>> Members

        bool IEquatable<LazyReference<T>>.Equals(LazyReference<T> other)
        {
            return other != null &&
                   other.GetType() == GetType() &&
                   other.m_node == m_node &&
                   other.m_resourceName == m_resourceName;
        }

        #endregion
    }
}