/*
 *                    BioJava development code
 *
 * This code may be freely distributed and modified under the
 * terms of the GNU Lesser General Public Licence.  This should
 * be distributed with the code.  If you do not have a copy,
 * see:
 *
 *      http://www.gnu.org/copyleft/lesser.html
 *
 * Copyright for this code is held jointly by the individual
 * authors.  These should be listed in @author doc comments.
 *
 * For more information on the BioJava project and its aims,
 * or to join the biojava-l mailing list, visit the home page
 * at:
 *
 *      http://www.biojava.org/
 *
 */

package org.biojavax.bio.db.biosql;
import java.lang.reflect.Method;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import org.biojava.bio.BioException;
import org.biojava.bio.seq.db.IllegalIDException;
import org.biojava.utils.ChangeEvent;
import org.biojava.utils.ChangeSupport;
import org.biojava.utils.ChangeVetoException;
import org.biojavax.bio.BioEntry;
import org.biojavax.bio.db.AbstractBioEntryDB;
import org.biojavax.bio.db.BioEntryDB;
import org.biojavax.bio.db.BioEntryDBLite;
import org.biojavax.bio.db.HashBioEntryDB;


/**
 *
 * @author Richard Holland
 * @author David Scott
 * @since 1.5
 */
public class BioSQLBioEntryDB extends AbstractBioEntryDB {
    
    private Object session;
    private String name;
    
    private Method createQuery;
    private Method setParameter;
    private Method list;
    private Method delete;
    private Method saveOrUpdate;
    
    /** Creates a new instance of BioSQLBioEntryDB */
    public BioSQLBioEntryDB(Object session) {
        this(null,session);
    }
    
    /** Creates a new instance of BioSQLBioEntryDB */
    public BioSQLBioEntryDB(String name, Object session) {
        this.name = name;
        this.session = session;
        try {
            // Lazy load the Session class from Hibernate.
            Class hibernateSession = session.getClass();
            Class realHibernateSession = Class.forName("org.hibernate.Session");
            // Test to see if our parameter is really a Session
            if (!realHibernateSession.isAssignableFrom(hibernateSession))
                throw new IllegalArgumentException("Parameter must be a org.hibernate.Session object");
            this.session = session;
            // Lookup the createQuery method
            this.createQuery = hibernateSession.getMethod("createQuery", new Class[]{String.class});
            this.delete = hibernateSession.getMethod("delete", new Class[]{String.class,Object.class});
            this.saveOrUpdate = hibernateSession.getMethod("saveOrUpdate", new Class[]{String.class,Object.class});
            // Lazy load the Query class from Hibernate.
            Class hibernateQuery = Class.forName("org.hibernate.Query");
            // Lookup the setParameter and uniqueQuery methods
            this.setParameter = hibernateQuery.getMethod("setParameter", new Class[]{int.class,Object.class});
            this.list = hibernateQuery.getMethod("list", new Class[]{});
        } catch (ClassNotFoundException e) {
            throw new RuntimeException(e);
        } catch (NoSuchMethodException e) {
            throw new RuntimeException(e);
        }
    }
    
    public String getName() {
        return this.name;
    }
    
    public Object getHibernateSession() {
        return this.session;
    }
    
    public Set ids() {
        try {
            // Build the query object
            String queryText = "select distinct name from BioEntry";
            Object query = this.createQuery.invoke(this.session, new Object[]{queryText});
            // Get the results
            List result = (List)this.list.invoke(query, (Object[])null);
            // Return the found object, if found - null if not.
            return new HashSet(result);
        } catch (Exception e) {
            // Throw the exception with our nice message
            throw new RuntimeException("Error while trying to load all names",e);
        }
    }
    
    public BioEntry getBioEntry(String id) throws IllegalIDException, BioException {
        try {
            // Build the query object
            String queryText = "from BioEntry where name = ?";
            Object query = this.createQuery.invoke(this.session, new Object[]{queryText});
            // Set the parameters
            query = this.setParameter.invoke(query, new Object[]{new Integer(0), id});
            // Get the results
            List result = (List)this.list.invoke(query, (Object[])null);
            // If the result doesn't just have a single entry, throw an exception
            if (result.size()==0) throw new IllegalIDException("Id not found: "+id);
            else if (result.size()>1) throw new IllegalIDException("Multiple records found with that id - use getBioEntrys: "+id);
            // Return the found object, if found - null if not.
            return (BioEntry)result.get(0);
        } catch (Exception e) {
            // Throw the exception with our nice message
            throw new RuntimeException("Error while trying to load by id: "+id,e);
        }
    }
    
    public BioEntryDB getBioEntrys(Set ids) throws BioException, IllegalIDException {
        return this.getBioEntrys(ids,null);
    }
    
    public BioEntryDB getBioEntrys(Set ids, BioEntryDB db) throws BioException, IllegalIDException {
        if (db==null) db = new HashBioEntryDB();
        try {
            for (Iterator i = ids.iterator(); i.hasNext(); ) {
                String id = (String)i.next();
                // Build the query object
                String queryText = "from BioEntry where name = ?";
                Object query = this.createQuery.invoke(this.session, new Object[]{queryText});
                // Set the parameters
                query = this.setParameter.invoke(query, new Object[]{new Integer(0), id});
                // Get the results
                List result = (List)this.list.invoke(query, (Object[])null);
                // If the result doesn't just have a single entry, throw an exception
                if (result.size()==0) throw new IllegalIDException("Id not found: "+id);
                // Add the results to the results db.
                for (Iterator j = result.iterator(); j.hasNext(); ) db.addBioEntry((BioEntry)j.next());
            }
        } catch (Exception e) {
            // Throw the exception with our nice message
            throw new RuntimeException("Error while trying to load by ids: "+ids,e);
        }
        return db;
    }
    
    public void removeBioEntry(String id) throws IllegalIDException, BioException, ChangeVetoException {
        if(!hasListeners(BioEntryDBLite.BIOENTRYS)) {
            this._removeBioEntry(id);
        } else {
            ChangeSupport changeSupport = getChangeSupport(BioEntryDBLite.BIOENTRYS);
            synchronized(changeSupport) {
                ChangeEvent ce = new ChangeEvent(
                        this,
                        BioEntryDBLite.BIOENTRYS,
                        null,
                        id
                        );
                changeSupport.firePreChangeEvent(ce);
                this._removeBioEntry(id);
                changeSupport.firePostChangeEvent(ce);
            }
        }
    }
    
    private void _removeBioEntry(String id) throws IllegalIDException, BioException, ChangeVetoException {
        try {
            // Find the object
            BioEntry be = this.getBioEntry(id);
            // Get the results
            this.delete.invoke(this.session, new Object[]{"BioEntry",be});
        } catch (Exception e) {
            // Throw the exception with our nice message
            throw new RuntimeException("Error while trying to delete by id: "+id,e);
        }
    }
    
    public void addBioEntry(BioEntry seq) throws IllegalIDException, BioException, ChangeVetoException {
        if(!hasListeners(BioEntryDBLite.BIOENTRYS)) {
            this._addBioEntry(seq);
        } else {
            ChangeSupport changeSupport = getChangeSupport(BioEntryDBLite.BIOENTRYS);
            synchronized(changeSupport) {
                ChangeEvent ce = new ChangeEvent(
                        this,
                        BioEntryDBLite.BIOENTRYS,
                        null,
                        seq
                        );
                changeSupport.firePreChangeEvent(ce);
                this._addBioEntry(seq);
                changeSupport.firePostChangeEvent(ce);
            }
        }
    }
    
    public void _addBioEntry(BioEntry seq) throws IllegalIDException, BioException, ChangeVetoException {
        try {
            // Get the results
            this.saveOrUpdate.invoke(this.session, new Object[]{"BioEntry",seq});
        } catch (Exception e) {
            // Throw the exception with our nice message
            throw new RuntimeException("Error while trying to save BioEntry with id: "+seq.getName(),e);
        }
    }
    
}