//
// MessageImpl.cs
//
// Author:
//	Atsushi Enomoto <atsushi@ximian.com>
//
// Copyright (C) 2006 Novell, Inc.  http://www.novell.com
//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Runtime.Serialization;
using System.Xml;
using System.IO;

namespace System.ServiceModel.Channels
{
	// Apparently Microsoft should have split Message class into
	// two diffferent public classes such as IncomingMessage and
	// OutgoingMessage.
	internal class XmlReaderMessage : Message
	{
		MessageVersion version;
		XmlDictionaryReader reader;
		MessageHeaders headers;
		MessageProperties properties = new MessageProperties ();
		bool is_empty, is_fault, body_started, body_consumed;
		int max_headers;

		string body;

		public XmlReaderMessage (MessageVersion version, XmlDictionaryReader reader, int maxSizeOfHeaders)
		{
			this.version = version;
			this.reader = reader;
			this.max_headers = maxSizeOfHeaders;

			ReadEnvelopeStart ();
			// Headers and IsEmpty are consumed at this stage.
			// Body content is not.
			ReadBodyStart ();

			StringWriter sw = new StringWriter ();
			using (XmlDictionaryWriter bodyXml = XmlDictionaryWriter.CreateDictionaryWriter (XmlWriter.Create (sw))) {
				while (!reader.EOF && reader.NodeType != XmlNodeType.EndElement)
					bodyXml.WriteNode (reader, false);
			}
			this.body = sw.ToString ();
		}

		public override MessageHeaders Headers {
			get {
				if (headers == null)
					ReadHeaders ();
				return headers;
			}
		}

		public override bool IsEmpty {
			get {
				if (!body_started)
					ReadBodyStart ();
				return is_empty;
			}
		}

		public override bool IsFault {
			get {
				if (!body_started)
					ReadBodyStart ();
				return is_fault;
			}
		}

		public override MessageProperties Properties {
			get { return properties; }
		}

		public override MessageVersion Version {
			get { return version; }
		}

		protected override string OnGetBodyAttribute (
			string localName, string ns)
		{
			if (headers == null)
				ReadHeaders ();
			return reader.GetAttribute (localName, ns);
		}

		protected override XmlDictionaryReader OnGetReaderAtBodyContents ()
		{
			XmlDictionaryReader newReader = XmlDictionaryReader.CreateDictionaryReader (XmlReader.Create (new StringReader (this.body)));
			newReader.MoveToContent();
			return newReader;
		}

		protected override void OnWriteBodyContents (
			XmlDictionaryWriter writer)
		{
			XmlDictionaryReader reader = GetReaderAtBodyContents ();
			while (!reader.EOF && reader.NodeType != XmlNodeType.EndElement)
				writer.WriteNode (reader, false);
		}

		static readonly char [] whitespaceChars = new char [] {' ', '\t', '\r', '\n'};

		void ReadEnvelopeStart ()
		{
			reader.MoveToContent ();
			if (reader.IsEmptyElement)
				throw new ArgumentException ("Missing message content XML.");
			reader.ReadStartElement ("Envelope", Version.Envelope.Namespace);

			// SOAP Header
			reader.MoveToContent ();
		}

		void ReadHeaders ()
		{
			if (headers != null)
				throw new InvalidOperationException ("XmlReader at headers is already consumed.");

			string envNS = Version.Envelope.Namespace;

			headers = new MessageHeaders (version, max_headers);
			if (reader.LocalName != "Header" || reader.NamespaceURI != envNS)
				return;

			bool isEmptyHeader = reader.IsEmptyElement;
			reader.ReadStartElement ("Header", envNS);
			reader.MoveToContent ();
			if (isEmptyHeader)
				return;

			XmlDocument doc = null;
			while (!reader.EOF && reader.NodeType != XmlNodeType.EndElement) {
				if (doc == null)
					doc = new XmlDocument ();
				XmlElement el = doc.ReadNode (reader) as XmlElement;
				if (el != null)
					headers.Add (MessageHeader.CreateInternalHeader (el, envNS));
				// FIXME: handle UnderstoodHeaders as well.
				reader.MoveToContent ();
			}
			reader.ReadEndElement ();
			reader.MoveToContent ();
		}

		void ReadBodyStart ()
		{
			// read headers in advance.
			if (headers == null)
				ReadHeaders ();

			// SOAP Body
			body_started = true;
			is_empty = reader.IsEmptyElement;
			if (reader.MoveToAttribute ("Id", Constants.WsuNamespace)) {
				BodyId = reader.Value;
				reader.MoveToElement ();
			}
			reader.ReadStartElement ("Body", Version.Envelope.Namespace);
			if (reader.NodeType == XmlNodeType.EndElement) {
				is_empty = true;
				reader.Read ();
			} else {
				reader.MoveToContent ();
				if (reader.NodeType == XmlNodeType.Element &&
				    reader.LocalName == "Fault" &&
				    reader.NamespaceURI == Version.Envelope.Namespace)
					is_fault = true;
			}
		}
	}

	internal abstract class MessageImplBase : Message
	{
		MessageHeaders headers;
		MessageProperties properties = new MessageProperties ();

		public MessageImplBase (MessageVersion version, string action)
		{
			headers = new MessageHeaders (version);
			if (action != null)
				headers.Action = action;
		}

		public override MessageHeaders Headers {
			get { return headers; }
		}

		public override MessageProperties Properties {
			get { return properties; }
		}

		public override MessageVersion Version {
			get { return Headers.MessageVersion; }
		}
	}

	internal class EmptyMessage : MessageImplBase
	{
		public EmptyMessage (MessageVersion version, string action)
			: base (version, action)
		{
		}

		public override bool IsEmpty {
			get { return true; }
		}

		protected override void OnWriteBodyContents (
			XmlDictionaryWriter writer)
		{
		}

		protected override MessageBuffer OnCreateBufferedCopy (
			int maxBufferSize)
		{
			return new DefaultMessageBuffer (Headers, Properties);
		}
	}

	internal class SimpleMessage : MessageImplBase
	{
		BodyWriter body;
		bool is_fault;

		public SimpleMessage (MessageVersion version,
			string action, BodyWriter body, bool isFault)
			: base (version, action)
		{
			this.body = body;
			this.is_fault = isFault;
		}

		public override bool IsEmpty {
			get { return false; }
		}

		public override bool IsFault {
			get { return is_fault; }
		}

		protected override void OnWriteBodyContents (
			XmlDictionaryWriter writer)
		{
			body.WriteBodyContents (writer);
		}
	}
}