//
// System.Net.HttpWebResponse
//
// Authors:
// 	Lawrence Pit (loz@cable.a2000.nl)
// 	Gonzalo Paniagua Javier (gonzalo@ximian.com)
//      Daniel Nauck    (dna(at)mono-project(dot)de)
//
// (c) 2002 Lawrence Pit
// (c) 2003 Ximian, Inc. (http://www.ximian.com)
// (c) 2008 Daniel Nauck
//

//
// 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.Collections;
using System.Globalization;
using System.IO;
using System.Net.Sockets;
using System.Runtime.Serialization;
using System.Text;
#if NET_2_0
using System.IO.Compression;
#endif

namespace System.Net 
{
	[Serializable]
	public class HttpWebResponse : WebResponse, ISerializable, IDisposable
	{
		Uri uri;
		WebHeaderCollection webHeaders;
		CookieCollection cookieCollection;
		string method;
		Version version;
		HttpStatusCode statusCode;
		string statusDescription;
		long contentLength;
		string contentType;
		CookieContainer cookie_container;

		bool disposed;
		Stream stream;
		
		// Constructors
		
		internal HttpWebResponse (Uri uri, string method, WebConnectionData data, CookieContainer container)
		{
			this.uri = uri;
			this.method = method;
			webHeaders = data.Headers;
			version = data.Version;
			statusCode = (HttpStatusCode) data.StatusCode;
			statusDescription = data.StatusDescription;
			stream = data.stream;
			contentLength = -1;

			try {
				string cl = webHeaders ["Content-Length"];
#if NET_2_0
				if (String.IsNullOrEmpty (cl) || !Int64.TryParse (cl, out contentLength))
					contentLength = -1;
#else
				if (cl != null && cl != String.Empty)
					contentLength = (long) UInt64.Parse (cl);
#endif
			} catch (Exception) {
				contentLength = -1;
			}

			if (container != null) {
				this.cookie_container = container;	
				FillCookies ();
			}
#if NET_2_0
			string content_encoding = webHeaders ["Content-Encoding"];
			if (content_encoding == "gzip" && (data.request.AutomaticDecompression & DecompressionMethods.GZip) != 0)
				stream = new GZipStream (stream, CompressionMode.Decompress);
			else if (content_encoding == "deflate" && (data.request.AutomaticDecompression & DecompressionMethods.Deflate) != 0)
				stream = new DeflateStream (stream, CompressionMode.Decompress);
#endif
		}

#if NET_2_0
		[Obsolete ("Serialization is obsoleted for this type", false)]
#endif
		protected HttpWebResponse (SerializationInfo serializationInfo, StreamingContext streamingContext)
		{
			SerializationInfo info = serializationInfo;

			uri = (Uri) info.GetValue ("uri", typeof (Uri));
			contentLength = info.GetInt64 ("contentLength");
			contentType = info.GetString ("contentType");
			method = info.GetString ("method");
			statusDescription = info.GetString ("statusDescription");
			cookieCollection = (CookieCollection) info.GetValue ("cookieCollection", typeof (CookieCollection));
			version = (Version) info.GetValue ("version", typeof (Version));
			statusCode = (HttpStatusCode) info.GetValue ("statusCode", typeof (HttpStatusCode));
		}
		
		// Properties
		
		public string CharacterSet {
			// Content-Type   = "Content-Type" ":" media-type
			// media-type     = type "/" subtype *( ";" parameter )
			// parameter      = attribute "=" value
			// 3.7.1. default is ISO-8859-1
			get { 
				string contentType = ContentType;
				if (contentType == null)
					return "ISO-8859-1";
				string val = contentType.ToLower (); 					
				int pos = val.IndexOf ("charset=");
				if (pos == -1)
					return "ISO-8859-1";
				pos += 8;
				int pos2 = val.IndexOf (';', pos);
				return (pos2 == -1)
				     ? contentType.Substring (pos) 
				     : contentType.Substring (pos, pos2 - pos);
			}
		}
		
		public string ContentEncoding {
			get {
				CheckDisposed ();
				string h = webHeaders ["Content-Encoding"];
				return h != null ? h : "";
			}
		}
		
		public override long ContentLength {		
			get {
				return contentLength;
			}
		}
		
		public override string ContentType {		
			get {
				CheckDisposed ();

				if (contentType == null)
					contentType = webHeaders ["Content-Type"];

				return contentType;
			}
		}
		
		public CookieCollection Cookies {
			get {
				CheckDisposed ();
				if (cookieCollection == null)
					cookieCollection = new CookieCollection ();
				return cookieCollection;
			}
			set {
				CheckDisposed ();
				cookieCollection = value;
			}
		}
		
		public override WebHeaderCollection Headers {		
			get {
#if ONLY_1_1
				CheckDisposed ();
#endif
				return webHeaders; 
			}
		}

#if NET_2_0
		static Exception GetMustImplement ()
		{
			return new NotImplementedException ();
		}
		
		[MonoTODO]
		public override bool IsMutuallyAuthenticated
		{
			get {
				throw GetMustImplement ();
			}
		}
#endif
		
		public DateTime LastModified {
			get {
				CheckDisposed ();
				try {
					string dtStr = webHeaders ["Last-Modified"];
					return MonoHttpDate.Parse (dtStr);
				} catch (Exception) {
					return DateTime.Now;	
				}
			}
		}
		
		public string Method {
			get {
				CheckDisposed ();
				return method; 
			}
		}
		
		public Version ProtocolVersion {
			get {
				CheckDisposed ();
				return version; 
			}
		}
		
		public override Uri ResponseUri {		
			get {
				CheckDisposed ();
				return uri; 
			}
		}		
		
		public string Server {
			get {
				CheckDisposed ();
				return webHeaders ["Server"]; 
			}
		}
		
		public HttpStatusCode StatusCode {
			get {
				return statusCode; 
			}
		}
		
		public string StatusDescription {
			get {
				CheckDisposed ();
				return statusDescription; 
			}
		}

		// Methods
#if !NET_2_0
		public override int GetHashCode ()
		{
			return base.GetHashCode ();
		}
#endif
		
		public string GetResponseHeader (string headerName)
		{
			CheckDisposed ();
			string value = webHeaders [headerName];
			return (value != null) ? value : "";
		}

		internal void ReadAll ()
		{
			WebConnectionStream wce = stream as WebConnectionStream;
			if (wce == null)
				return;
				
			try {
				wce.ReadAll ();
			} catch {}
		}

		public override Stream GetResponseStream ()
		{
			CheckDisposed ();
			if (stream == null)
				return Stream.Null;  
			if (0 == String.Compare (method, "HEAD", true)) // see par 4.3 & 9.4
				return Stream.Null;  

			return stream;
		}
		
		void ISerializable.GetObjectData (SerializationInfo serializationInfo,
		   				  StreamingContext streamingContext)
		{
			GetObjectData (serializationInfo, streamingContext);
		}

#if NET_2_0
		protected override
#endif
		void GetObjectData (SerializationInfo serializationInfo,
				    StreamingContext streamingContext)
		{
			SerializationInfo info = serializationInfo;

			info.AddValue ("uri", uri);
			info.AddValue ("contentLength", contentLength);
			info.AddValue ("contentType", contentType);
			info.AddValue ("method", method);
			info.AddValue ("statusDescription", statusDescription);
			info.AddValue ("cookieCollection", cookieCollection);
			info.AddValue ("version", version);
			info.AddValue ("statusCode", statusCode);
		}

		// Cleaning up stuff

		public override void Close ()
		{
			((IDisposable) this).Dispose ();
		}
		
		void IDisposable.Dispose ()
		{
			Dispose (true);
			GC.SuppressFinalize (this);  
		}

#if !NET_2_0
		protected virtual
#endif
		void Dispose (bool disposing) 
		{
			if (this.disposed)
				return;
			this.disposed = true;
			
			if (disposing) {
				// release managed resources
				uri = null;
#if !NET_2_0
				webHeaders = null;
#endif
				cookieCollection = null;
				method = null;
				version = null;
				statusDescription = null;
			}
			
			// release unmanaged resources
			Stream st = stream;
			stream = null;
			if (st != null)
				st.Close ();
		}
		
		private void CheckDisposed () 
		{
			if (disposed)
				throw new ObjectDisposedException (GetType ().FullName);
		}

		void FillCookies ()
		{
			if (webHeaders == null)
				return;

			string [] values = webHeaders.GetValues ("Set-Cookie");
			if (values != null) {
				foreach (string va in values)
					SetCookie (va);
			}

			values = webHeaders.GetValues ("Set-Cookie2");
			if (values != null) {
				foreach (string va in values)
					SetCookie2 (va);
			}
		}

		void SetCookie (string header)
		{
			string name, val;
			Cookie cookie = null;
			CookieParser parser = new CookieParser (header);

			while (parser.GetNextNameValue (out name, out val)) {
				if ((name == null || name == "") && cookie == null)
					continue;

				if (cookie == null) {
					cookie = new Cookie (name, val);
					continue;
				}

				name = name.ToUpper ();
				switch (name) {
				case "COMMENT":
					if (cookie.Comment == null)
						cookie.Comment = val;
					break;
				case "COMMENTURL":
					if (cookie.CommentUri == null)
						cookie.CommentUri = new Uri (val);
					break;
				case "DISCARD":
					cookie.Discard = true;
					break;
				case "DOMAIN":
					if (cookie.Domain == "")
						cookie.Domain = val;
					break;
#if NET_2_0
				case "HTTPONLY":
					cookie.HttpOnly = true;
					break;
#endif
				case "MAX-AGE": // RFC Style Set-Cookie2
					if (cookie.Expires == DateTime.MinValue) {
						try {
						cookie.Expires = cookie.TimeStamp.AddSeconds (UInt32.Parse (val));
						} catch {}
					}
					break;
				case "EXPIRES": // Netscape Style Set-Cookie
					if (cookie.Expires != DateTime.MinValue)
						break;

					cookie.Expires = TryParseCookieExpires (val);
					break;
				case "PATH":
					cookie.Path = val;
					break;
				case "PORT":
					if (cookie.Port == null)
						cookie.Port = val;
					break;
				case "SECURE":
					cookie.Secure = true;
					break;
				case "VERSION":
					try {
						cookie.Version = (int) UInt32.Parse (val);
					} catch {}
					break;
				}
			}

			if (cookieCollection == null)
				cookieCollection = new CookieCollection ();

			if (cookie.Domain == "")
				cookie.Domain = uri.Host;

			cookieCollection.Add (cookie);
			if (cookie_container != null)
				cookie_container.Add (uri, cookie);
		}

		void SetCookie2 (string cookies_str)
		{
			string [] cookies = cookies_str.Split (',');
	
			foreach (string cookie_str in cookies)
				SetCookie (cookie_str);
		}

		string[] cookieExpiresFormats =
			new string[] { "r",
					"ddd, dd'-'MMM'-'yyyy HH':'mm':'ss 'GMT'",
					"ddd, dd'-'MMM'-'yy HH':'mm':'ss 'GMT'" };

		DateTime TryParseCookieExpires (string value)
		{
			if (value == null || value.Length == 0)
				return DateTime.MinValue;

			for (int i = 0; i < cookieExpiresFormats.Length; i++)
			{
				try {
					DateTime cookieExpiresUtc = DateTime.ParseExact (value, cookieExpiresFormats [i], CultureInfo.InvariantCulture);

					//convert UTC/GMT time to local time
#if NET_2_0
					cookieExpiresUtc = DateTime.SpecifyKind (cookieExpiresUtc, DateTimeKind.Utc);
					return TimeZone.CurrentTimeZone.ToLocalTime (cookieExpiresUtc);
#else
					//DateTime.Kind is only available on .NET 2.0, so do some calculation
					TimeSpan localOffset = TimeZone.CurrentTimeZone.GetUtcOffset (cookieExpiresUtc.Date);
					return cookieExpiresUtc.Add (localOffset);
#endif
				} catch {}
			}

			//If we can't parse Expires, use cookie as session cookie (expires is DateTime.MinValue)
			return DateTime.MinValue;
		}
	}	

	class CookieParser {
		string header;
		int pos;
		int length;

		public CookieParser (string header) : this (header, 0)
		{
		}

		public CookieParser (string header, int position)
		{
			this.header = header;
			this.pos = position;
			this.length = header.Length;
		}

		public bool GetNextNameValue (out string name, out string val)
		{
			name = null;
			val = null;

			if (pos >= length)
				return false;

			name = GetCookieName ();
			if (pos < header.Length && header [pos] == '=') {
				pos++;
				val = GetCookieValue ();
			}

			if (pos < length && header [pos] == ';')
				pos++;

			return true;
		}

		string GetCookieName ()
		{
			int k = pos;
			while (k < length && Char.IsWhiteSpace (header [k]))
				k++;

			int begin = k;
			while (k < length && header [k] != ';' &&  header [k] != '=')
				k++;

			pos = k;
			return header.Substring (begin, k - begin).Trim ();
		}

		string GetCookieValue ()
		{
			if (pos >= length)
				return null;

			int k = pos;
			while (k < length && Char.IsWhiteSpace (header [k]))
				k++;

			int begin;
			if (header [k] == '"'){
				int j;
				begin = ++k;

				while (k < length && header [k] != '"')
					k++;

				for (j = k; j < length && header [j] != ';'; j++)
					;
				pos = j;
			} else {
				begin = k;
				while (k < length && header [k] != ';')
					k++;
				pos = k;
			}
				
			return header.Substring (begin, k - begin).Trim ();
		}
	}
}