using System;
using System.Collections.ObjectModel;
using JD.Kernel.StaticHelpers;

namespace JD.TeaBoxAddinSystem.Addins.Description
{
    /// <summary>
    /// A collection of objects that becomes readonly when the addin that it belongs to is loaded.
    /// </summary>
    /// <remarks>NOT a collection of addins :)</remarks>
    internal class AddinCollection<T> : Collection<T>
    {
        #region Variables

        private Module m_owner;

        #endregion

        #region Constructor

        /// <summary>
        /// Constructor.
        /// </summary>
        internal AddinCollection()
            : this(null)
        {
        }

        /// <summary>
        /// Constructor.
        /// </summary>
        /// <param name="owner"></param>
        internal AddinCollection(Module owner)
        {
            m_owner = owner;
        }

        #endregion

        #region Properties

        internal Module Owner
        {
            get
            {
                return m_owner;
            }
            set
            {
                if (m_owner != value)
                {
                    m_owner = value;

                    OnOwnerChanged(EventArgs.Empty);
                }
            }
        }

        #endregion

        #region Methods

        /// <summary>
        /// OnOwnerChanged.
        /// </summary>
        /// <param name="e"></param>
        internal virtual void OnOwnerChanged(EventArgs e)
        {
        }

        private void ThrowIfLoaded()
        {
            if (Owner != null)
            {
                Owner.ThrowIfLoaded();
            }
        }

        /// <summary>
        /// Overriden.
        /// </summary>
        /// <param name="index"></param>
        /// <param name="item"></param>
        protected override void InsertItem(int index, T item)
        {
            Throw.IfNull(item, "item");
            ThrowIfLoaded();
            base.InsertItem(index, item);
        }

        /// <summary>
        /// Overriden.
        /// </summary>
        /// <param name="index"></param>
        protected override void RemoveItem(int index)
        {
            ThrowIfLoaded();
            base.RemoveItem(index);
        }

        /// <summary>
        /// Overriden.
        /// </summary>
        /// <param name="index"></param>
        /// <param name="item"></param>
        protected override void SetItem(int index, T item)
        {
            Throw.IfNull(item, "item");
            ThrowIfLoaded();
            base.SetItem(index, item);
        }

        /// <summary>
        /// Overriden.
        /// </summary>
        protected override void ClearItems()
        {
            ThrowIfLoaded();
            base.ClearItems();
        }

        #endregion
    }
}