//
// WebMessageEncoder.cs
//
// Author:
//	Atsushi Enomoto  <atsushi@ximian.com>
//
// Copyright (C) 2008 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.IO;
using System.Runtime.Serialization.Json;
using System.ServiceModel;
using System.ServiceModel.Dispatcher;
using System.Text;
using System.Xml;

namespace System.ServiceModel.Channels
{
	internal class WebMessageEncoder : MessageEncoder
	{
		internal const string ScriptPropertyName = "618BC2B0-38AA-21A3-DB4A-404FC87B9B11"; // randomly generated

		WebMessageEncodingBindingElement source;

		public WebMessageEncoder (WebMessageEncodingBindingElement source)
		{
			this.source = source;
		}

		public override string ContentType {
#if NET_2_1
			get { return MediaType; }
#else
			get { return MediaType + "; charset=" + source.WriteEncoding.HeaderName; }
#endif
		}

		// FIXME: find out how it can be customized.
		public override string MediaType {
			get { return "application/xml"; }
		}

		public override MessageVersion MessageVersion {
			get { return MessageVersion.None; }
		}

		public override bool IsContentTypeSupported (string contentType)
		{
			if (contentType == null)
				throw new ArgumentNullException ("contentType");
			return true; // anything is accepted.
		}

		public override Message ReadMessage (ArraySegment<byte> buffer, BufferManager bufferManager, string contentType)
		{
			throw new NotImplementedException ();
		}

		public override Message ReadMessage (Stream stream, int maxSizeOfHeaders, string contentType)
		{
			if (stream == null)
				throw new ArgumentNullException ("stream");

			contentType = contentType ?? "application/octet-stream";

			Encoding enc = Encoding.UTF8;
			var ct = new System.Net.Mime.ContentType (contentType);
			if (ct.CharSet != null)
				enc = Encoding.GetEncoding (ct.CharSet);

			WebContentFormat fmt = WebContentFormat.Xml;
			if (source.ContentTypeMapper != null)
				fmt = source.ContentTypeMapper.GetMessageFormatForContentType (contentType);
			else {
				switch (ct.MediaType) {
				case "application/json":
					fmt = WebContentFormat.Json;
					break;
				case "application/xml":
					fmt = WebContentFormat.Xml;
					break;
				default:
					fmt = WebContentFormat.Raw;
					break;
				}
			}

			Message msg = null;
			WebBodyFormatMessageProperty wp = null;
			switch (fmt) {
			case WebContentFormat.Xml:
				// FIXME: is it safe/unsafe/required to keep XmlReader open?
				msg = Message.CreateMessage (MessageVersion.None, null, XmlReader.Create (new StreamReader (stream, enc)));
				wp = new WebBodyFormatMessageProperty (WebContentFormat.Xml);
				break;
			case WebContentFormat.Json:
				// FIXME: is it safe/unsafe/required to keep XmlReader open?
#if NET_2_1
				msg = Message.CreateMessage (MessageVersion.None, null, JsonReaderWriterFactory.CreateJsonReader (stream, source.ReaderQuotas));
#else
				msg = Message.CreateMessage (MessageVersion.None, null, JsonReaderWriterFactory.CreateJsonReader (stream, enc, source.ReaderQuotas, null));
#endif
				wp = new WebBodyFormatMessageProperty (WebContentFormat.Json);
				break;
			case WebContentFormat.Raw:
				msg = new WebMessageFormatter.RawMessage (stream);
				wp = new WebBodyFormatMessageProperty (WebContentFormat.Raw);
				break;
			default:
				throw new SystemException ("INTERNAL ERROR: cannot determine content format");
			}
			if (wp != null)
				msg.Properties.Add (WebBodyFormatMessageProperty.Name, wp);
			msg.Properties.Encoder = this;
			return msg;
		}

		WebContentFormat GetContentFormat (Message message)
		{
			string name = WebBodyFormatMessageProperty.Name;
			if (message.Properties.ContainsKey (name))
				return ((WebBodyFormatMessageProperty) message.Properties [name]).Format;

			switch (MediaType) {
			case "application/xml":
			case "text/xml":
				return WebContentFormat.Xml;
			case "application/json":
			case "text/json":
				return WebContentFormat.Json;
			case "application/octet-stream":
				return WebContentFormat.Raw;
			default:
				return WebContentFormat.Default;
			}
		}

		public override void WriteMessage (Message message, Stream stream)
		{
			if (message == null)
				throw new ArgumentNullException ("message");

			// Handle /js and /jsdebug as the special cases.
			var script = message.Properties [ScriptPropertyName] as string;
			if (script != null) {
				var bytes = source.WriteEncoding.GetBytes (script);
				stream.Write (bytes, 0, bytes.Length);
				return;
			}

			if (!MessageVersion.Equals (message.Version))
				throw new ProtocolException (String.Format ("MessageVersion {0} is not supported", message.Version));
			if (stream == null)
				throw new ArgumentNullException ("stream");

			switch (GetContentFormat (message)) {
			case WebContentFormat.Xml:
#if NET_2_1
				using (XmlWriter w = XmlDictionaryWriter.CreateDictionaryWriter (XmlWriter.Create (new StreamWriter (stream, source.WriteEncoding))))
					message.WriteMessage (w);
#else
				using (XmlWriter w = XmlDictionaryWriter.CreateTextWriter (stream, source.WriteEncoding, false))
					message.WriteMessage (w);
#endif
				break;
			case WebContentFormat.Json:
				using (XmlWriter w = JsonReaderWriterFactory.CreateJsonWriter (stream, source.WriteEncoding, false))
					message.WriteMessage (w);
				break;
			case WebContentFormat.Raw:
				var rmsg = (WebMessageFormatter.RawMessage) message;
				var src = rmsg.Stream;
				if (src == null) // null output
					break;

				int len = 0;
				byte [] buffer = new byte [4096];
				while ((len = src.Read (buffer, 0, buffer.Length)) > 0)
					stream.Write (buffer, 0, len);
				break;
			case WebContentFormat.Default:
				throw new SystemException ("INTERNAL ERROR: cannot determine content format");
			}
		}

		public override ArraySegment<byte> WriteMessage (Message message, int maxMessageSize, BufferManager bufferManager,
								 int messageOffset)
		{
			throw new NotImplementedException ();
		}
	}
}