//
// System.Web.Services.Protocols.WebServiceHelper.cs
//
// Author:
//   Lluis Sanchez Gual (lluis@ximian.com)
//
// Copyright (C) Ximian, Inc. 2003
//

//
// 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.Net;
using System.Text;
using System.Xml;
using System.Xml.Schema;
using System.Xml.Serialization;
using System.Web.Services.Description;

namespace System.Web.Services.Protocols
{
	internal class WebServiceHelper
	{
		public const string SoapEnvelopeNamespace = "http://schemas.xmlsoap.org/soap/envelope/";
		static readonly char [] trimChars = { '"', '\'' };
		static readonly bool prettyXml;
		
		static WebServiceHelper ()
		{
			string pxml = Environment.GetEnvironmentVariable ("MONO_WEBSERVICES_PRETTYXML");
			prettyXml = (pxml != null && pxml != "no");
		}
		
		public static XmlTextWriter CreateXmlWriter (Stream s)
		{
			// What a waste of UTF8encoders, but it has to be thread safe.
			XmlTextWriter xtw = new XmlTextWriter (s, new UTF8Encoding (false));
				
			if (prettyXml)
				xtw.Formatting = Formatting.Indented;
				
			return xtw;
		}
		
		public static Encoding GetContentEncoding (string cts, out string content_type)
		{
			string encoding;

			encoding = "utf-8";
			int start = 0;
			int idx = cts.IndexOf (';');
			if (idx == -1)
				content_type = cts;
			else
				content_type = cts.Substring (0, idx);

			content_type = content_type.Trim ();
			for (start = idx + 1; idx != -1;)
			{
				idx = cts.IndexOf (";", start);
				string body;
				if (idx == -1)
					body = cts.Substring (start);
				else 
				{
					body = cts.Substring (start, idx - start);
					start = idx + 1;
				}
				body = body.Trim ();
				if (body.StartsWith ("charset="))
				{
					encoding = body.Substring (8);
					encoding = encoding.TrimStart (trimChars).TrimEnd (trimChars);
				}
			}

			return Encoding.GetEncoding (encoding);
		}

		public static void WriteSoapMessage (XmlTextWriter xtw, SoapTypeStubInfo info, SoapBindingUse methodUse, XmlSerializer bodySerializer, object bodyContent, SoapHeaderCollection headers)
		{
			xtw.WriteStartDocument ();
			xtw.WriteStartElement ("soap", "Envelope", WebServiceHelper.SoapEnvelopeNamespace);
			xtw.WriteAttributeString ("xmlns", "xsi", null, XmlSchema.InstanceNamespace);
			xtw.WriteAttributeString ("xmlns", "xsd", null, XmlSchema.Namespace);

			// Serialize headers
			if (headers != null)
			{
				foreach (SoapHeader header in headers) 
				{
					XmlSerializer ser = info.GetHeaderSerializer (header.GetType(), methodUse);
					xtw.WriteStartElement ("soap", "Header", WebServiceHelper.SoapEnvelopeNamespace);
					ser.Serialize (xtw, header);
					xtw.WriteEndElement ();
				}
			}

			// Serialize body
			xtw.WriteStartElement ("soap", "Body", WebServiceHelper.SoapEnvelopeNamespace);
			bodySerializer.Serialize (xtw, bodyContent);

			xtw.WriteEndElement ();
			xtw.WriteEndElement ();
			xtw.Flush ();
		}

		public static void ReadSoapMessage (XmlTextReader xmlReader, SoapTypeStubInfo typeStubInfo, SoapBindingUse methodUse, XmlSerializer bodySerializer, out object body, out SoapHeaderCollection headers)
		{
			xmlReader.MoveToContent ();
			xmlReader.ReadStartElement ("Envelope", WebServiceHelper.SoapEnvelopeNamespace);

			headers = ReadHeaders (typeStubInfo, methodUse, xmlReader);

			xmlReader.MoveToContent ();
			xmlReader.ReadStartElement ("Body", WebServiceHelper.SoapEnvelopeNamespace);
			xmlReader.MoveToContent ();
			
			if (xmlReader.LocalName == "Fault" && xmlReader.NamespaceURI == SoapEnvelopeNamespace)
				bodySerializer = Fault.Serializer;

			body = bodySerializer.Deserialize (xmlReader);
		}

		static SoapHeaderCollection ReadHeaders (SoapTypeStubInfo typeStubInfo, SoapBindingUse methodUse, XmlTextReader xmlReader)
		{
			SoapHeaderCollection headers = new SoapHeaderCollection ();
			while (! (xmlReader.NodeType == XmlNodeType.Element && xmlReader.LocalName == "Body" && xmlReader.NamespaceURI == WebServiceHelper.SoapEnvelopeNamespace))
			{
				if (xmlReader.NodeType == XmlNodeType.Element && xmlReader.LocalName == "Header" 
				    && xmlReader.NamespaceURI == WebServiceHelper.SoapEnvelopeNamespace && !xmlReader.IsEmptyElement)
				{
					xmlReader.ReadStartElement ();
					xmlReader.MoveToContent ();
					XmlQualifiedName qname = new XmlQualifiedName (xmlReader.LocalName, xmlReader.NamespaceURI);
					XmlSerializer headerSerializer = typeStubInfo.GetHeaderSerializer (qname, methodUse);
					if (headerSerializer != null)
					{
						SoapHeader header = (SoapHeader) headerSerializer.Deserialize (xmlReader);
						headers.Add (header);
					}
					else
					{
						while (xmlReader.NodeType == XmlNodeType.EndElement)
							xmlReader.Skip ();	// TODO: Check if the header has mustUnderstand=true
						xmlReader.Skip ();
					}
				}
				else
					xmlReader.Skip ();
			}
			return headers;
		}

		public static void InvalidOperation (string message, WebResponse response, Encoding enc)
		{
			if (response == null)
				throw new InvalidOperationException (message);

			if (enc == null)
				enc = Encoding.UTF8;

			StringBuilder sb = new StringBuilder ();
			sb.Append (message);
			sb.Append ("\r\nResponse error message:\r\n--\r\n");

			try {
				StreamReader resp = new StreamReader (response.GetResponseStream (), enc);
				sb.Append (resp.ReadToEnd ());
			} catch (Exception) {
			}

			throw new InvalidOperationException (sb.ToString ());
		}
	}
}