RSS Feed Aggregator and Blogging Smart Client

// Copyright � 2005 by Omar Al Zabir. All rights are reserved.
// 
// If you like this code then feel free to go ahead and use it.
// The only thing I ask is that you don't remove or alter my copyright notice.
//
// Your use of this software is entirely at your own risk. I make no claims or
// warrantees about the reliability or fitness of this code for any particular purpose.
// If you make changes or additions to this code please mark your code as being yours.
// 
// website http://www.oazabir.com, email OmarAlZabir@gmail.com, msn oazabir@hotmail.com
using System;
using System.IO;
using System.Text;
using System.Xml;
using System.Web;
using System.Net;
using System.Net.Sockets;
using System.Diagnostics;
using System.Xml.XPath;
using System.Collections;
using System.Security.Cryptography;
using System.Configuration;

namespace RSSBlogAPI
{
	/// <summary>
	/// Metaweblog API for WordPress and B2Evolution
	/// </summary>
	public class MetaWeblog : BlogAPIBase
	{
		private WebLog _WebLog;

		private readonly string _GetCategoriesMethodName;
		private readonly string _PostMethodName;

		public MetaWeblog( WebLog log )
		{
			this._WebLog = log;

			// Different blog engines have different method names
			if( log.Engine == EngineEnum.B2Evolution )
			{
				_GetCategoriesMethodName = "b2.getCategories";
				_PostMethodName = "b2.newPost";
			}
			else
			{
				_GetCategoriesMethodName = "metaWeblog.getCategories";
				_PostMethodName = "metaWeblog.newPost";
			}
		}
		public override bool HasCategories
		{
			get { return true; }
		}

		public override bool HasBlogId
		{
			get { return true; }
		}
		public override string EngineName
		{
			get { return "MetaWebLog (Movable type, dasBlog, wordpress)"; }
		}

		public override string HelpText
		{
			get { return "Movable type, dasBlog, wordpress"; }
		}

		
		public override void Test()
		{
			this.GetCategories();
		}

		/// <summary>
		/// Get categories from the blog engine.
		/// </summary>
		/// <returns></returns>
		public override Category [] GetCategories()
		{
			HttpWebRequest request = CreateRequest( "POST" );

			byte [] xml = BuildXmlRpc( this._GetCategoriesMethodName, this.BlogId, this.Username, this.Password );
			request.ContentLength = xml.Length;

			using( Stream requestStream = request.GetRequestStream())
				requestStream.Write( xml, 0, xml.Length );

			using( HttpWebResponse response = request.GetResponse() as HttpWebResponse )
			{
				if ( response.StatusCode != HttpStatusCode.OK )
					throw new ApplicationException( response.StatusDescription );

				using( Stream responseStream = response.GetResponseStream() )
					using( StreamReader reader = new StreamReader( responseStream, Encoding.UTF8 ) )
						return DeserializeCategoriesXml( reader );
			}
		}

		/// <summary>
		/// Post to weblog
		/// </summary>
		/// <param name="post"></param>
		/// <returns></returns>
		public override string PostItem( Post post )
		{
			HttpWebRequest request = CreateRequest( "POST" );

			byte [] xml;
			if( EngineEnum.B2Evolution ==  this._WebLog.Engine )
			{
				// B2 Supports special format
				xml = BuildXmlRpc( this._PostMethodName, 
					this.BlogId, string.Empty,
					this.Username, this.Password, 
					post.Text, true, post.Title, post.Categories[0].Id.ToString(), 
					post.Date.ToString( "yyyy-MM-dd hh:mm:sszzz" ) );
			}
			else
			{
				xml = BuildXmlRpc( this._PostMethodName, this.BlogId, 
					this.Username, this.Password, post, true );
			}

			request.ContentLength = xml.Length;

			using( Stream requestStream = request.GetRequestStream())
				requestStream.Write( xml, 0, xml.Length );

			using( HttpWebResponse response = request.GetResponse() as HttpWebResponse )
			{
				if ( response.StatusCode != HttpStatusCode.OK )
					throw new ApplicationException( response.StatusDescription );

				using( Stream responseStream = response.GetResponseStream() )
					using( StreamReader reader = new StreamReader( responseStream, Encoding.UTF8 ) )
						return DeserializePostXml( reader );
			}
		}

		private Category [] DeserializeCategoriesXml( StreamReader reader )
		{
			ArrayList list = new ArrayList();

			XPathDocument xDoc = new XPathDocument( reader );
			XPathNavigator navigator = xDoc.CreateNavigator();

			XPathNodeIterator fault = navigator.Select( "/methodResponse/fault/value" );

			if ( fault.Count == 0 )
			{
				XPathNodeIterator values = navigator.Select( "/methodResponse/params/param/value/array/data/value" );

				while( values.MoveNext() )
				{
					Category category = GetCategory( values.Current );

					if ( category != null )
						list.Add( category );
				}

				return list.ToArray( typeof( Category ) ) as Category [];
			}
			else
			{
				fault.MoveNext();
				throw new ApplicationException("Invalid content in XML: " + fault.Current.Value);
			}
		}

		private string DeserializePostXml( StreamReader reader )
		{
			ArrayList list = new ArrayList();

#if(DEBUG)
			string response = reader.ReadToEnd();
			Debug.WriteLine( response );
			XPathDocument xDoc = new XPathDocument( new StringReader( response ) );
#else
			XPathDocument xDoc = new XPathDocument( reader );
#endif
			
			XPathNavigator navigator = xDoc.CreateNavigator();

			XPathNodeIterator fault = navigator.Select( "/methodResponse/fault/value" );

			if ( fault.Count != 0 )
			{
				fault.MoveNext();
				throw new ApplicationException( GetFault( fault.Current ) );
			}
			else
			{
				XPathNodeIterator postID = navigator.Select( "/methodResponse/params/param/value/string" );
				if( postID.Count != 0 )
				{
					return postID.Current.Value;
				}
				else
				{
					return string.Empty;
				}
			}
		}

		private Category GetCategory( XPathNavigator navigator )
		{
			Category category = new Category();

			XPathNodeIterator members = navigator.Select( "struct/member" );

			while( members.MoveNext() )
			{
				string memberName = ( string )members.Current.Evaluate( "string(name/text())" );
				string memberValue = ( string )members.Current.Evaluate( "string(value/string/text())" );

				if ( memberName.ToLower() == "categoryid" )
					category.Id = memberValue;
				else if ( memberName.ToLower() == "title" || 
						  memberName.ToLower() == "categoryname" )
					category.Title = memberValue;
			}

			return ( category.Title != string.Empty && category.Id != string.Empty ) ? category : null;
		}

		private string GetFault( XPathNavigator navigator )
		{
			XPathNodeIterator members = navigator.Select( "struct/member" );

			while( members.MoveNext() )
			{
				string memberName = ( string )members.Current.Evaluate( "string(name/text())" );
				string memberValue = ( string )members.Current.Evaluate( "string(value/string/text())" );
				if ( memberName.ToLower() == "faultstring" )
					return memberValue;
			}

			return string.Empty;
		}

		private byte [] BuildXmlRpc( string method, params object [] args )
		{
			using( MemoryStream mStream = new MemoryStream() )
			{
				XmlTextWriter xWriter = new XmlTextWriter( mStream, Encoding.UTF8 );

				xWriter.Indentation = 1;
				xWriter.Formatting = Formatting.Indented;
				xWriter.IndentChar = '\t';
				xWriter.QuoteChar = '"';

				xWriter.WriteStartDocument();
				xWriter.WriteStartElement( "methodCall" );
				xWriter.WriteElementString( "methodName", method );

				xWriter.WriteStartElement( "params" );

				foreach( object param in args )
				{
					xWriter.WriteStartElement( "param" );
					xWriter.WriteStartElement( "value" );

					if ( param is string )
						xWriter.WriteElementString( "string", param.ToString() );
					else if ( param is bool )
						xWriter.WriteElementString( "boolean", ( ( bool ) param ) ? "1" : "0" );
					else if( param is DateTime )
						xWriter.WriteElementString( "dateTime.iso8601", ((DateTime)param).ToString( "yyyyMMddThh:mm:sszzz" ) );
					else if ( param is Post )
					{
						xWriter.WriteStartElement( "struct" );
						WritePost( xWriter, ( Post )param );
						xWriter.WriteEndElement();
					}
                    
					xWriter.WriteEndElement();
					xWriter.WriteEndElement();
				}

				xWriter.WriteEndElement();
				xWriter.WriteEndElement();

				xWriter.Flush();

				return mStream.ToArray();
			}
		}

		private void WritePost( XmlTextWriter xWriter, Post post )
		{
			// This format is for Word Press
			string date = post.Date.ToString( "yyyyMMddThh:mm:sszzz" );
			//string date = "20050701T09:18:58Z";

			//WriteMember( xWriter, "dateTime", "dateCreated", date );
			WriteMember( xWriter, "dateTime.iso8601", "dateCreated", date );
			WriteMember( xWriter, "string", "description", post.Text );
			WriteMember( xWriter, "string", "title", post.Title );
			WriteCategories( xWriter, "categories", post.Categories );
			WriteMember( xWriter, "string", "link", string.Empty );
			WriteMember( xWriter, "string", "permalink", string.Empty );
			WriteMember( xWriter, "string", "postid", string.Empty );
		}

		private void WriteMember( XmlTextWriter xWriter, string type, string name, string val )
		{
			xWriter.WriteStartElement( "member" );
			xWriter.WriteElementString( "name", name );
			xWriter.WriteStartElement( "value" );
			xWriter.WriteElementString( type, val );
			xWriter.WriteEndElement();
			xWriter.WriteEndElement();
		}

		private void WriteCategories( XmlTextWriter xWriter, string name, Category [] val )
		{
			xWriter.WriteStartElement( "member" );
			xWriter.WriteElementString( "name", "categories" );
			xWriter.WriteStartElement( "value" );
			xWriter.WriteStartElement( "array" );
			xWriter.WriteStartElement( "data" );

			foreach( Category cat in val )
			{
				xWriter.WriteStartElement( "value" );
				xWriter.WriteElementString( "string", cat.Title );
				xWriter.WriteEndElement();
			}

			xWriter.WriteEndElement();
			xWriter.WriteEndElement();
			xWriter.WriteEndElement();
			xWriter.WriteEndElement();
		}
	}
}