using System.Collections.Generic;
using System.Collections.ObjectModel;

namespace JD.TeaBoxAddinSystem.Addins.Description
{
    /// <summary>
    /// A keyed collection of <see cref="AddinObject"/>s.
    /// </summary>
    internal abstract class AddinObjectKeyedCollection<K, V> : KeyedCollection<K, V> where V : AddinObject
    {
        #region Variables

        private Module m_owner;

        #endregion

        #region Constructor

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

        /// <summary>
        /// Constructor.
        /// </summary>
        /// <param name="owner"></param>
        internal AddinObjectKeyedCollection(Module owner)
            : this(owner, null)
        {
        }

        /// <summary>
        /// Constructor.
        /// </summary>
        /// <param name="owner"></param>
        /// <param name="keyComparer"></param>
        internal AddinObjectKeyedCollection(Module owner, IEqualityComparer<K> keyComparer)
            : base(keyComparer)
        {
            m_owner = owner;
        }

        #endregion

        #region Properties

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

                    foreach (V item in this)
                    {
                        item.Module = m_owner;
                    }
                }
            }
        }

        #endregion

        #region Methods

        /// <summary>
        /// Overriden.
        /// </summary>
        /// <param name="index"></param>
        /// <param name="item"></param>
        protected override void InsertItem(int index, V item)
        {
            ThrowIfLoaded();

            base.InsertItem(index, item);
            item.Module = m_owner;
        }

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

            this[index].Module = null;
            base.RemoveItem(index);
        }

        /// <summary>
        /// Overriden.
        /// </summary>
        /// <param name="index"></param>
        /// <param name="item"></param>
        protected override void SetItem(int index, V item)
        {
            ThrowIfLoaded();

            this[index].Module = null;
            base.SetItem(index, item);
            item.Module = m_owner;
        }

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

            foreach (V item in this)
            {
                item.Module = null;
            }

            base.ClearItems();
        }

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

        #endregion
    }
}