using System;
using System.Data;
using System.Configuration;
//Ini Jena libraries
using com.hp.hpl.jena.db;
using com.hp.hpl.jena.rdf.model;
using com.hp.hpl.jena.query;
using ikvm.lang;
using com.microsoft.sqlserver.jdbc;
//Fin Jena libraries
using System.Xml;
using System.Xml.XPath;

namespace wsGeoConceptsSemWebLayer
{
    /// <summary>
    /// Allows the access to an RDF Persitence Model
    /// Relational DataBase Jena Persistence Model is used.
    /// </summary>
    public class JenaPersistenceRDB : IDisposable
    {
        #region Class variables
        Model modelRDF;
        IDBConnection connRDB;
        #endregion Class variables

        #region Private variables
        private bool IsDisposed = false;
        #endregion Private variables

        #region Constructor
        /// <summary>
        /// Creates a new JenaPersitenceRDF object.
        /// Connects to an SQL Server 2005 RDB: dbserver, db, dbuser, dbpassword
        /// It opens the Jena model with "modelName". If it doesn't exist, the model is created.
        /// </summary>
        /// <param name="modelName">Jena model Name</param>
        /// <param name="dbserver">Server url and instance</param>
        /// <param name="db">Database name</param>
        /// <param name="dbuser">Datatabase user name</param>
        /// <param name="dbpass">Datababase user password</param>
        public JenaPersistenceRDB(String modelName, String dbserver, String db, String dbuser, String dbpass)
        {
            String M_DB_URL = "jdbc:microsft:sqlserver://" + dbserver + ";databaseName=" + db; // database URL
            String M_DB_USER = dbuser;     // database user id
            String M_DB_PASSWD = dbpass;   // database user password
            String M_DB = "MsSQL";  // database engine

            try
            {
                M_DB_URL = "jdbc:sqlserver://" + dbserver + ";databaseName=" + db;
                // Following line has some problems with some versions of MS jdbc driver.
                //System.Activator.CreateInstance("sqldriver", "com.microsoft.sqlserver.jdbc.SQLServerDriver");
                java.lang.Class.forName(typeof(com.microsoft.sqlserver.jdbc.SQLServerDriver).FullName);

                connRDB = new DBConnection(M_DB_URL, M_DB_USER, M_DB_PASSWD, M_DB);

                if (connRDB == null)
                {
                    // Exception management
                }
                else
                {
                    // create a model maker with the given connection parameters
                    ModelMaker mkModel = ModelFactory.createModelRDBMaker(connRDB);

                    if (!connRDB.containsModel(modelName))
                    {
                        // create a new model
                       modelRDF = mkModel.createModel(modelName);
                    }
                    else
                    {
                        // open a previously created model
                       modelRDF = mkModel.openModel(modelName);
                    }
                }
            }
            catch (Exception e)
            {
                throw (e);
            }
        }
        #endregion Constructor

        #region Destructor
        /// <summary>
        /// Close object's Database connection and Jena model
        /// </summary>
        public void CloseRDBConnection()
        {
            try
            {
                if (modelRDF != null && !modelRDF.isClosed())
                    modelRDF.close();

                if (connRDB != null)
                    connRDB.close();
            }
            catch (Exception ex)
            {
                throw (ex);
            }
        }
        /// <summary>
        /// Close object's model
        /// </summary>
        public void CloseModel()
        {
            try
            {
                if (modelRDF != null && !modelRDF.isClosed())
                    modelRDF.close();
            }
            catch (Exception ex)
            {
                throw (ex);
            }
        }
        /// <summary>
        /// Overrides standard Dispose method, to free open resources
        /// </summary>
        public void Dispose()
        {
            //Pass true in dispose method to clean managed resources too and say GC to skip finalize in next line.
            Dispose(true);
            //If dispose is called already then say GC to skip finalize on this instance.
            GC.SuppressFinalize(this);
        }

        /// <summary>
        /// Free open resources (Jena model and connection)
        /// </summary>
        /// <param name="disposedStatus"></param>
        protected virtual void Dispose(bool disposedStatus)
        {
            if (!IsDisposed)
            {
                IsDisposed = true;
                // Released unmanaged Resources
                if (disposedStatus)
                {
                    CloseModel();
                    CloseRDBConnection();
                }
            }
        }
        #endregion Destructor

        #region RDB Access Methods

        #endregion RDB Access Methods
    }
}