Scheme of Persistence

using System;
using System.Collections;
using System.Reflection;
using System.Xml;

namespace SQLSPMapping
{
	
	[AttributeUsage(AttributeTargets.Class | AttributeTargets.Property | AttributeTargets.Field)]
	public class Persistent:Attribute
	{
		static Hashtable persistentClass=new Hashtable();
		private readonly Class cl=new Class();
		public Class Class{get{return cl;}}
		public Persistent(Type type)
		{
			if(persistentClass.Contains(type.GUID))
			{
				cl=(Class)persistentClass[type.GUID];
			}
			else
			{
				Load(cl,type);	
				persistentClass[type.GUID]=cl;
			}
		}

		
		private void Load(Class cl,Type tipo)
		{	
			cl.Name=tipo.FullName.Substring(tipo.FullName.LastIndexOf('.')+1);
			string lugAssembly=tipo.Assembly.Location;
			string trayClass=tipo.FullName.Substring(0,tipo.FullName.Length-cl.Name.Length-1).Replace(".","/");
			string nomArc=lugAssembly.Substring(0,lugAssembly.LastIndexOf('.'))+".pers.xml";
			string trayCnTipo="Mapping/"+trayClass+"/Class[@name='"+cl.Name+"']";
			string traySPTipo="Mapping/"+trayClass+"/Class[@name='"+cl.Name+"']/Procedure";
			string traySelTipo="Mapping/"+trayClass+"/Class[@name='"+cl.Name+"']/Select";
			string nomProc="";
			string nomSP="";
			string assemblyConnection="";
			string assemblyConnClass="";
			string assemblyConnString="";
			string typeAsmConnection="";
			string typeConnClass="";
			string typeConnString="";
			string procedureAsmConnection="";
			string procedureConnClass="";
			string procedureConnString="";
			Procedure proc;
			XmlDocument doc=new XmlDocument();
			doc.Load (nomArc);
			XmlNode nodoSel=doc.SelectSingleNode("Mapping");
			if(nodoSel!=null)
			{
				GetValuesConnection(ref assemblyConnection,ref assemblyConnClass,ref assemblyConnString,nodoSel);
			}
			nodoSel=doc.SelectSingleNode(trayCnTipo);
			if(nodoSel!=null)
			{
				GetValuesConnection(ref typeAsmConnection,ref typeConnClass,ref typeConnString,nodoSel);
			}

			nodoSel=doc.SelectSingleNode(traySelTipo);
			if(nodoSel!=null)
			{
				XmlNode nodoSel1=nodoSel.SelectSingleNode("Query");
				if(nodoSel!=null)
				{
					cl.QuerySelect=nodoSel1.InnerText;
				}
				else
				{
					throw new ApplicationException("Statement 'Select' without query for class"+cl.Name);
				}
				LoadParameter(nodoSel,cl.SelectParameters,"Parameters/parameter");
			}


			XmlNodeList nodos=doc.SelectNodes(traySPTipo);
			foreach(XmlNode nodo in nodos)
			{
				procedureAsmConnection="";
				procedureConnClass="";
				procedureConnString="";
				GetValuesConnection(ref procedureAsmConnection,ref procedureConnClass,ref procedureConnString,nodo);
				nomProc=nodo.Attributes["Method"].Value;
				nomSP=nodo.Attributes["StoreProcedure"].Value;
				proc=new Procedure(nomSP,nomProc);
				proc.Connection=nodo.Attributes["Connection"]==null ? "" : nodo.Attributes["Connection"].Value;
				LoadParameter(nodo,proc.InputParameters,"InputParameters/parameter");
				LoadParameter(nodo,proc.OutputParamters,"OutputParameters/parameter");
				proc.AssemblyConnection=procedureAsmConnection.Length!=0?procedureAsmConnection:typeAsmConnection.Length!=0?typeAsmConnection:assemblyConnection;
				proc.ClsConnection=procedureConnClass.Length!=0?procedureConnClass:typeConnClass.Length!=0?typeConnClass:assemblyConnClass;
				proc.Connection=procedureConnString.Length!=0?procedureConnString:typeConnString.Length!=0?typeConnString:assemblyConnString;
				cl.Methods.Add(nomProc,proc);
			}
		}
		
		private void LoadParameter(XmlNode nodo,ArrayList al,string query)
		{
			XmlNodeList parameters=nodo.SelectNodes(query);
			try
			{
				Parameter p;
				string nameProp;
				string nameSP;
				foreach(XmlNode parameter in parameters)
				{
					nameProp=parameter.Attributes["Property"].Value;
					nameSP=parameter.Attributes["ParameterBD"].Value;
					p=new Parameter(nameSP,nameProp,0);
					al.Add(p);
				}
			}
			catch(Exception)
			{
				throw new ApplicationException("No estan bien definidos los parametros");
			}
		}
		

		private void GetValuesConnection(ref string assm,ref string className,ref string connectionString,XmlNode nodo)
		{
			if(nodo.Attributes["Assembly"]!=null)
			{
				assm=nodo.Attributes["Assembly"].Value;
			}
			if(nodo.Attributes["ConnectionClass"]!=null)
			{
				className=nodo.Attributes["ConnectionClass"].Value;
			}
			if(nodo.Attributes["Connection"]!=null)
			{
				connectionString=nodo.Attributes["Connection"].Value;
			}
		}
	}
}