// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
 
/*++
                                                                              
                                                                              
    Abstract:
        This file contains the definition of a class that defines
        the common functionality required to serialize a 
        UIElementCollection
 
                                                                       
--*/
using System.Collections;
using System.Windows.Media;
 
namespace System.Windows.Xps.Serialization
{
    /// <summary>
    /// Class defining common functionality required to
    /// serialize a UIElementCollection.
    /// </summary>
    internal class ReachUIElementCollectionSerializerAsync :
                   ReachSerializerAsync
    {
        #region Constructor
 
        /// <summary>
        /// Constructor for class ReachUIElementCollectionSerializer
        /// </summary>
        /// <param name="manager">
        /// The serialization manager, the services of which are
        /// used later in the serialization process of the type.
        /// </param>
        public
        ReachUIElementCollectionSerializerAsync(
            PackageSerializationManager manager
            ):
        base(manager)
        {
 
        }
 
        #endregion Constructor
 
        #region Public Methods
        public
        override
        void
        AsyncOperation(
            ReachSerializerContext context
            )
        {
            if(context == null)
            {
 
            }
           
            switch (context.Action) 
            {
                case SerializerAction.endPersistObjectData:
                {
                    EndPersistObjectData();
                    break;
                }
 
                case SerializerAction.serializeNextUIElement:
                {
                    UIElementCollectionSerializerContext thisContext = context as UIElementCollectionSerializerContext;
 
                    if(thisContext != null)
                    {
                        SerializeNextUIElement(thisContext.Enumerator,
                                               thisContext.ObjectContext);
                    }
 
                    break;
                }
                
                default:
                {
                    base.AsyncOperation(context);
                    break;
                }
            }
        }
 
        /// <summary>
        /// The main method that is called to serialize a UIElementCollection.
        /// </summary>
        /// <param name="serializedObject">
        /// Instance of object to be serialized.
        /// </param>
        public
        override
        void
        SerializeObject(
            Object serializedObject
            )
        {
            base.SerializeObject(serializedObject);
        }
 
        #endregion Public Methods
 
        #region Internal Methods
        
        /// <summary>
        /// The method is called once the object data is discovered at that 
        /// point of the serialization process.
        /// </summary>
        /// <param name="serializableObjectContext">
        /// The context of the object to be serialized at this time.
        /// </param>
        internal
        override
        void
        PersistObjectData(
            SerializableObjectContext   serializableObjectContext
            )
        {
            ArgumentNullException.ThrowIfNull(serializableObjectContext);
 
            IEnumerable enumerableObject = serializableObjectContext.TargetObject as IEnumerable;
 
            if (enumerableObject == null)
            {
                throw new XpsSerializationException(SR.Format(SR.MustBeOfType, "serializableObjectContext.TargetObject", typeof(IEnumerable)));
            }
 
            //
            // Serialize the PageContent Items contained within the collection 
            //
            SerializeUIElements(serializableObjectContext);
        }
 
        #endregion Internal Methods
 
 
        #region Private Methods
 
        /// <summary>
        /// This is being called to serialize the Page Content items
        /// contained within the collection
        /// </summary>
        private
        void 
        SerializeUIElements(
            SerializableObjectContext   serializableObjectContext
            )
        {
            //
            // Serialize each PageContent in PageContentCollection
            //
            IEnumerator enumerator = ((IEnumerable)serializableObjectContext.TargetObject).GetEnumerator();
 
            enumerator.Reset();
 
            UIElementCollectionSerializerContext context = new UIElementCollectionSerializerContext(this,
                                                                                                    serializableObjectContext,
                                                                                                    enumerator,
                                                                                                    SerializerAction.serializeNextUIElement);
 
            ((IXpsSerializationManagerAsync)SerializationManager).OperationStack.Push(context);
        }
 
 
        private
        void
        SerializeNextUIElement(
            IEnumerator                 enumerator,
            SerializableObjectContext   serializableObjectContext
            )
        {
            if(enumerator.MoveNext())
            {
 
                UIElementCollectionSerializerContext context = new UIElementCollectionSerializerContext(this,
                                                                                                        serializableObjectContext,
                                                                                                        enumerator,
                                                                                                        SerializerAction.serializeNextUIElement);
 
 
                ((IXpsSerializationManagerAsync)SerializationManager).OperationStack.Push(context);
 
                object uiElement = enumerator.Current;
 
                SerializeUIElement(uiElement);
            }
        }
 
        /// <summary>
        /// Called to serialize a single UIElement
        /// </summary>
        private 
        void 
        SerializeUIElement(
            object uiElement
            )
        {
            Visual visual = uiElement as Visual;
 
            if(visual != null)
            {
                ReachSerializer serializer = SerializationManager.GetSerializer(visual);
 
                if(serializer!=null)
                {
                    serializer.SerializeObject(visual);
                }
                else
                {
                    throw new XpsSerializationException(SR.ReachSerialization_NoSerializer);
                }
            }
        }
 
        #endregion Private Methods
    };
 
    internal class UIElementCollectionSerializerContext :
                   ReachSerializerContext
    {
        public
        UIElementCollectionSerializerContext(
            ReachSerializerAsync        serializer,
            SerializableObjectContext   objectContext,
            IEnumerator                 enumerator,
            SerializerAction            action
            ):
            base(serializer,objectContext,action)
        {
            this._enumerator = enumerator;
        }
 
 
        public
        IEnumerator
        Enumerator
        {
            get
            {
                return _enumerator;
            }
        }
 
        private
        IEnumerator     _enumerator;
    };
}