// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
 
using System.Collections;
using System.Windows.Documents;
 
namespace System.Windows.Xps.Serialization
{
    /// <summary>
    /// 
    /// </summary>
    internal class ReachDocumentReferenceCollectionSerializerAsync :
                   ReachSerializerAsync
    {
        /// <summary>
        /// Creates new serializer for a DocumentReferenceCollection
        /// </summary>
        /// <param name="manager">serialization manager for this seriaizer</param>
        public
        ReachDocumentReferenceCollectionSerializerAsync(
            PackageSerializationManager manager
            ):
        base(manager)
        {
 
        }
 
        public
        override
        void
        AsyncOperation(
            ReachSerializerContext context
            )
        {
            switch (context.Action) 
            {
                case SerializerAction.endPersistObjectData:
                {
                    EndPersistObjectData();
                    break;
                }
 
                case SerializerAction.serializeNextDocumentReference:
                {
                    DocumentReferenceCollectionSerializerContext thisContext = 
                    context as DocumentReferenceCollectionSerializerContext;
 
                    if(thisContext != null)
                    {
                        SerializeNextDocumentReference(thisContext.Enumerator,
                                                       thisContext.ObjectContext);
                    }
 
                    break;
                }
                
                default:
                {
                    base.AsyncOperation(context);
                    break;
                }
            }
        }
 
        /// <summary>
        /// 
        /// </summary>
        internal
        override
        void
        PersistObjectData(
            SerializableObjectContext   serializableObjectContext
            )
        {
            ArgumentNullException.ThrowIfNull(serializableObjectContext);
 
            // get DocumentReferenceCollection
            System.Collections.Generic.IEnumerable<DocumentReference> enumerableObject = serializableObjectContext.TargetObject as System.Collections.Generic.IEnumerable<DocumentReference>;
 
            if (enumerableObject == null)
            {
                throw new XpsSerializationException(SR.Format(SR.MustBeOfType, "serializableObjectContext.TargetObject", typeof(System.Collections.Generic.IEnumerable<DocumentReference>)));
            }
 
            SerializeDocumentReferences(serializableObjectContext);
        }
 
        internal
        override
        void
        EndPersistObjectData(
            )
        {
            //
            // do nothing in this stage
            //
        }
 
        /// <summary>
        /// This is being called to serialize the DocumentReference items
        /// contained within the colleciton
        /// </summary>
        private
        void
        SerializeDocumentReferences(
            SerializableObjectContext   serializableObjectContext
            )
        {
            IEnumerator enumerator = 
            ((System.Collections.Generic.IEnumerable<DocumentReference>)serializableObjectContext.TargetObject).
            GetEnumerator();
 
            enumerator.Reset();
 
            DocumentReferenceCollectionSerializerContext
            context = new DocumentReferenceCollectionSerializerContext(this,
                                                                       serializableObjectContext,
                                                                       enumerator,
                                                                       SerializerAction.serializeNextDocumentReference);
 
            ((IXpsSerializationManagerAsync)SerializationManager).OperationStack.Push(context);
        }
 
        private
        void
        SerializeNextDocumentReference(
            IEnumerator                 enumerator,
            SerializableObjectContext   serializableObjectContext
            )
        {
            if(enumerator.MoveNext())
            {
 
                DocumentReferenceCollectionSerializerContext
                context = new DocumentReferenceCollectionSerializerContext(this,
                                                                           serializableObjectContext,
                                                                           enumerator,
                                                                           SerializerAction.serializeNextDocumentReference);
 
 
                ((IXpsSerializationManagerAsync)SerializationManager).OperationStack.Push(context);
 
                object documentReference = enumerator.Current;
 
                SerializeDocumentReference(documentReference);
            }
        }
 
 
        /// <summary>
        ///     Called to serialize a single DocumentReference
        /// </summary>
        private 
        void
        SerializeDocumentReference(
            object documentReference
            )
        {
            ReachSerializer serializer = SerializationManager.GetSerializer(documentReference);
 
            if(serializer!=null)
            {
                serializer.SerializeObject(documentReference);
            }
            else
            {
                // should we throw if this is not a DocumentReference or just not do anything?
                throw new XpsSerializationException(SR.ReachSerialization_NoSerializer);
            }
        }
    };
 
 
    internal class DocumentReferenceCollectionSerializerContext :
                   ReachSerializerContext
    {
        public
        DocumentReferenceCollectionSerializerContext(
            ReachSerializerAsync        serializer,
            SerializableObjectContext   objectContext,
            IEnumerator                 enumerator,
            SerializerAction            action
            ):
            base(serializer,objectContext,action)
        {
            this._enumerator = enumerator;
        }
 
 
        public
        IEnumerator
        Enumerator
        {
            get
            {
                return _enumerator;
            }
        }
 
        private
        IEnumerator     _enumerator;
    };
}