// X2chAuthenticateThreadReader.cs

namespace Twin.Bbs
{
	using System;
	using System.Net;
	using System.IO.Compression;
	using Twin.Util;
	using System.IO;
	using System.Text;

	/// <summary>
	/// 認証を使って２ちゃんねる (www.2ch.net) のスレッドを読み込む機能を提供
	/// </summary>
	public class X2chAuthenticateThreadReader : X2chThreadReader
	{
		private HttpWebResponse _res = null;
		private bool firstRead = true;

		public X2chRokkaResponseState RokkaResponseState { get; private set; }

		public X2chAuthenticateThreadReader() : base()
		{
			RokkaResponseState = X2chRokkaResponseState.None;
		}

		/// <summary>
		/// スレッドを開く
		/// </summary>
		/// <param name="th"></param>
		public override bool Open(ThreadHeader header)
		{
			if (header == null) 
			{
				throw new ArgumentNullException("header");
			}
			if (IsOpen) 
			{
				throw new InvalidOperationException("既にストリームが開かれています");
			}

			headerInfo = header;
			firstRead = true;
			RokkaResponseState = X2chRokkaResponseState.None;

			if (header.Pastlog)
				return false;

			X2chAuthenticator authenticator = X2chAuthenticator.GetInstance();
			if (authenticator.HasSession)
			{
				X2chThreadHeader x2chHeader = header as X2chThreadHeader;
				if (x2chHeader != null)
				{
					HttpWebRequest req = (HttpWebRequest)WebRequest.Create(x2chHeader.AuthenticateUrl);
					req.Timeout = 15000;
					req.UserAgent = UserAgent;
					req.AllowAutoRedirect = false;
					
					// ** 9/26 削除 **
					// req.Headers.Add("Accept-Encoding", "gzip");
					
					// ** 9/26 追加 **
					req.AutomaticDecompression = DecompressionMethods.GZip;

					req.Headers.Add("Pragma", "no-cache");
					req.Headers.Add("Cache-Control", "no-cache");

					if (x2chHeader.ETag != String.Empty)
						req.Headers.Add("If-None-Match", x2chHeader.ETag);

					_res = (HttpWebResponse)req.GetResponse();

					//baseStream = _res.GetResponseStream();
					baseStream = FileUtility.CreateMemoryStream( _res.GetResponseStream() );
					baseStream.Position = 0;
					length = (int)baseStream.Length;

					RokkaResponseState = ParseRokkaFirstline( baseStream );

					if (_res.StatusCode == HttpStatusCode.OK)
					{
						/* 9 26削除
						using (GZipStream gzipInp = new GZipStream(_res.GetResponseStream(), CompressionMode.Decompress))
							baseStream = FileUtility.CreateMemoryStream(gzipInp);
						*/

						x2chHeader.ETag = _res.Headers["ETag"];
						x2chHeader.LastModified = _res.LastModified;

						index = header.GotResCount + 1;
						position = 0;
						isOpen = true;
					}
					else OnPastlog(new PastlogEventArgs(header));
				}
			}
			else
				OnPastlog(new PastlogEventArgs(header));

			// 過去ログなのでdat落ちに設定
			headerInfo.Pastlog = true;

			return isOpen;
		}

		//public override int Read( ResSetCollection resSets , out int byteParsed )
		//{
		//	if ( firstRead )
		//	{
		//		byte[] buf = new byte[1];
		//		int c;

		//		do
		//		{
		//			c = baseStream.Read( buf , 0 , buf.Length );
		//			// 最初の改行が来るまで読み飛ばす
		//		} while ( c != 0 && buf[0] != '\n' );

		//		firstRead = false;
		//	}

		//	return base.Read( resSets , out byteParsed );
		//}

		public override void Close()
		{
			base.Close();
			if (_res != null)
			{
				_res.Close();
				_res = null;
			}
		}


		private X2chRokkaResponseState ParseRokkaFirstline(Stream responseStream)
		{
			if (responseStream == null)
				throw new ArgumentNullException();

			var statusbytes = new System.Collections.Generic.List<byte>();
			byte[] buf = new byte[1];
			int c;
			do
			{
				c = baseStream.Read( buf , 0 , buf.Length );
				// 最初の改行が来るまで読み飛ばす
				// 2013/09/10 初めの行を処理結果コードエリアと定義＆宣言したので文字に取り込んでおく
				// http://q...content-available-to-author-only...h.net/test/read.cgi/operate/1366640919/119
				statusbytes.Add( buf[0] );
			} while ( c != 0 && buf[0] != '\n' );

			var line = base.dataParser.Encoding.GetString( statusbytes.ToArray() );

			//byte[] buf = new byte[256];
			//long firstpos = responseStream.Position;
			//responseStream.Read( buf , 0 , buf.Length );

			//using ( StringReader s = new StringReader( base.dataParser.Encoding.GetString( buf ) ) )
			//using ( StreamReader s = new StreamReader( responseStream ) )
			//{
			//	string line = s.ReadLine();
				//responseStream.Position += base.dataParser.Encoding.GetByteCount( line ); // 最初の1行分だけストリームを進めておく

				if (line.StartsWith("Success")) return X2chRokkaResponseState.Success;
				else if (line.StartsWith("Error 8008135")) return X2chRokkaResponseState.InvalidServerOrBoardOrThread;
				else if (line.StartsWith("Error 69")) return X2chRokkaResponseState.AuthenticationError;
				else if (line.StartsWith("Error 666")) return X2chRokkaResponseState.UrlError;
				else if (line.StartsWith("Error 420")) return X2chRokkaResponseState.TimeLimitError;
				else
				{
					// ステータスが見つからなかった場合は、ストリームの位置を元に戻しておく
					//responseStream.Position = firstpos;
					return X2chRokkaResponseState.Unknown;
				}
			//}
		}
	}

	
	/*
	   "Success"　　- The process has successfuly done. Following lines are achieved message with dat format
	    Error codes: 
　　　　inputError = "Error 8008135"　　　　　　invalid SERVER or BOARD or THREAD
　　　　authenticationError = "Error 69"　　　　invalid SID
　　　　urlError = "Error 666"　　　　　　　　　invalid OPTIONS
　　　　timeLimitError = "Error 420"　　　　　　 access too fast, interval between requests required
	 */
	public enum X2chRokkaResponseState
	{
		None = -2,
		Unknown = -1, // ステータスが不明
		Success = 0,
		InvalidServerOrBoardOrThread = 8008135,
		AuthenticationError = 89,
		UrlError = 666,
		TimeLimitError = 420,
	}
}