//---------------------------------------------------------------------
// <copyright file="EntitySetBaseCollection.cs" company="Microsoft">
//      Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>
//
// @owner       Microsoft
// @backupOwner Microsoft
//---------------------------------------------------------------------

using System;
using System.Collections;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Data.Common;
using System.Reflection;
using System.Text;
using System.Diagnostics;

namespace System.Data.Metadata.Edm
{
    /// <summary>
    /// Class representing a collection of entity set objects
    /// </summary>
    internal sealed class EntitySetBaseCollection : MetadataCollection<EntitySetBase>
    {
        // This collection allows changes to be intercepted before and after they are passed to MetadataCollection.  The interception
        // is required to update the EntitySet's back-reference to the EntityContainer.

        #region Constructors
        /// <summary>
        /// Default constructor for constructing an empty collection
        /// </summary>
        /// <param name="entityContainer">The entity container that has this entity set collection</param>
        /// <exception cref="System.ArgumentNullException">Thrown if the argument entityContainer is null</exception>
        internal EntitySetBaseCollection(EntityContainer entityContainer)
            : this(entityContainer, null)
        {
        }

        /// <summary>
        /// The constructor for constructing the collection with the given items
        /// </summary>
        /// <param name="entityContainer">The entity container that has this entity set collection</param>
        /// <param name="items">The items to populate the collection</param>
        /// <exception cref="System.ArgumentNullException">Thrown if the argument entityContainer is null</exception>
        internal EntitySetBaseCollection(EntityContainer entityContainer, IEnumerable<EntitySetBase> items)
            : base(items)
        {
            EntityUtil.GenericCheckArgumentNull(entityContainer, "entityContainer");
            _entityContainer = entityContainer;
        }
        #endregion

        #region Fields
        private readonly EntityContainer _entityContainer;
        #endregion

        #region Properties
        /// <summary>
        /// Gets an item from the collection with the given index
        /// </summary>
        /// <param name="index">The index to search for</param>
        /// <returns>An item from the collection</returns>
        /// <exception cref="System.ArgumentOutOfRangeException">Thrown if the index is out of the range for the Collection</exception>
        /// <exception cref="System.InvalidOperationException">Always thrown on setter</exception>
        public override EntitySetBase this[int index]
        {
            get
            {
                return base[index];
            }
            set
            {
                throw EntityUtil.OperationOnReadOnlyCollection();
            }
        }

        /// <summary>
        /// Gets an item from the collection with the given identity
        /// </summary>
        /// <param name="identity">The identity of the item to search for</param>
        /// <returns>An item from the collection</returns>
        /// <exception cref="System.ArgumentNullException">Thrown if identity argument passed in is null</exception>
        /// <exception cref="System.ArgumentException">Thrown if the Collection does not have an EntitySet with the given identity</exception>
        /// <exception cref="System.InvalidOperationException">Always thrown on setter</exception>
        public override EntitySetBase this[string identity]
        {
            get
            {
                return base[identity];
            }
            set
            {
                throw EntityUtil.OperationOnReadOnlyCollection();
            }
        }
        #endregion

        #region Methods
        /// <summary>
        /// Adds an item to the collection 
        /// </summary>
        /// <param name="item">The item to add to the list</param>
        /// <exception cref="System.ArgumentNullException">Thrown if item argument is null</exception>
        /// <exception cref="System.InvalidOperationException">Thrown if the item passed in or the collection itself instance is in ReadOnly state</exception>
        /// <exception cref="System.ArgumentException">Thrown if the EntitySetBase that is being added already belongs to another EntityContainer</exception>
        /// <exception cref="System.ArgumentException">Thrown if the EntitySetCollection already contains an EntitySet with the same identity</exception>
        public override void Add(EntitySetBase item)
        {
            EntityUtil.GenericCheckArgumentNull(item, "item");
            // Check to make sure the given entity set is not associated with another type
            ThrowIfItHasEntityContainer(item, "item");
            base.Add(item);

            // Fix up the declaring type
            item.ChangeEntityContainerWithoutCollectionFixup(_entityContainer);
        }

        /// <summary>
        /// Checks if the given entity set already has a entity container, if so, throw an exception
        /// </summary>
        /// <param name="entitySet">The entity set to check for</param>
        /// <param name="argumentName">The name of the argument from the caller</param>
        private static void ThrowIfItHasEntityContainer(EntitySetBase entitySet, string argumentName)
        {
            EntityUtil.GenericCheckArgumentNull(entitySet, argumentName);
            if (entitySet.EntityContainer != null)
            {
                throw EntityUtil.EntitySetInAnotherContainer(argumentName);
            }
        }
        #endregion
    }
}