//------------------------------------------------------------------------------
// <copyright file="CopyNodeSetAction.cs" company="Microsoft">
//     Copyright (c) Microsoft Corporation.  All rights reserved.
// </copyright>                                                                
// <owner current="true" primary="true">[....]</owner>
//------------------------------------------------------------------------------

namespace System.Xml.Xsl.XsltOld {
    using Res = System.Xml.Utils.Res;
    using System;
    using System.Diagnostics;
    using System.Xml;
    using System.Xml.XPath;

    internal sealed class CopyNodeSetAction : Action {
        private const int BeginEvent    = 2;
        private const int Contents      = 3;
        private const int Namespaces    = 4;
        private const int Attributes    = 5;
        private const int Subtree       = 6;
        private const int EndEvent      = 7;

        private static CopyNodeSetAction s_Action = new CopyNodeSetAction();

        internal static CopyNodeSetAction GetAction() {
            Debug.Assert(s_Action != null);
            return s_Action;
        }

        internal override void Execute(Processor processor, ActionFrame frame) {
            Debug.Assert(processor != null && frame != null);
            while (processor.CanContinue) {
                switch (frame.State) {
                case Initialized:
                    if (frame.NextNode(processor)) {
                        frame.State = BeginEvent;
                        goto case BeginEvent;
                    }
                    else {
                        frame.Finished();
                        break;
                    }
                case BeginEvent:
                    Debug.Assert(frame.State == BeginEvent);

                    if (SendBeginEvent(processor, frame.Node) == false) {
                        // This one wasn't output
                        break;
                    }
                    frame.State = Contents;
                    continue;

                case Contents:
                    Debug.Assert(frame.State == Contents);
                    XPathNodeType nodeType = frame.Node.NodeType;

                    if (nodeType == XPathNodeType.Element || nodeType == XPathNodeType.Root) {
                        processor.PushActionFrame(CopyNamespacesAction.GetAction(), frame.NodeSet);
                        frame.State = Namespaces;
                        break;
                    }

                    if (SendTextEvent(processor, frame.Node) == false) {
                        // This one wasn't output
                        break;
                    }
                    frame.State = EndEvent;
                    continue;

                case Namespaces:
                    processor.PushActionFrame(CopyAttributesAction.GetAction(), frame.NodeSet);
                    frame.State = Attributes;
                    break;

                case Attributes:
                    if (frame.Node.HasChildren) {
                        processor.PushActionFrame(GetAction(), frame.Node.SelectChildren(XPathNodeType.All));
                        frame.State = Subtree;
                        break;
                    }
                    frame.State = EndEvent;
                    goto case EndEvent;

                case Subtree:
                    //frame.Node.MoveToParent();
                    frame.State = EndEvent;
                    continue;

                case EndEvent:
                    Debug.Assert(frame.State == EndEvent);

                    if (SendEndEvent(processor, frame.Node) == false) {
                        // This one wasn't output
                        break;
                    }

                    frame.State = Initialized;
                    continue;
                }

                break;
            }
        }

        private static bool SendBeginEvent(Processor processor, XPathNavigator node) {
            return processor.CopyBeginEvent(node, node.IsEmptyElement);
        }

        private static bool SendTextEvent(Processor processor, XPathNavigator node) {
            return processor.CopyTextEvent(node);
        }

        private static bool SendEndEvent(Processor processor, XPathNavigator node) {
            return processor.CopyEndEvent(node);
        }
    }
}