package de.intevation.flys.importer;

import java.util.Iterator;
import java.util.Map;
import java.util.HashMap;

import java.math.BigDecimal;

import org.hibernate.SessionFactory;
import org.hibernate.Session;
import org.hibernate.Query;

import de.intevation.flys.backend.SessionFactoryProvider;

import de.intevation.flys.model.WstColumnValue;
import de.intevation.flys.model.WstColumn;

public class ImporterSession
{
    private static final ThreadLocal<ImporterSession> SESSION =
        new ThreadLocal<ImporterSession>() {
            @Override
            protected ImporterSession initialValue() {
                return new ImporterSession();
            }
        };

    protected Session databaseSession;

    protected Map<WstColumnValueKey, WstColumnValue> wstColumnValues;

    public static ImporterSession getInstance() {
        return SESSION.get();
    }

    public ImporterSession() {
        SessionFactory sessionFactory =
            SessionFactoryProvider.createSessionFactory();
        databaseSession = sessionFactory.openSession();
    }

    public Session getDatabaseSession() {
        return databaseSession;
    }

    public WstColumnValue getWstColumnValue(
        WstColumn  column,
        BigDecimal position,
        BigDecimal w
    ) {
        if (wstColumnValues == null) {
            loadWstColumnValues();
        }

        WstColumnValueKey key = new WstColumnValueKey(
            column.getId(),
            position.doubleValue(),
            w.doubleValue());

        WstColumnValue wcv = wstColumnValues.get(key);

        if (wcv != null) {
            return wcv;
        }

        wcv = new WstColumnValue(column, position, w);

        databaseSession.save(wcv);

        wstColumnValues.put(key, wcv);

        return wcv;
    }

    protected void loadWstColumnValues() {
        wstColumnValues = new HashMap<WstColumnValueKey, WstColumnValue>();

        Query query = databaseSession.createQuery("from WstColumnValue");

        for (Iterator iter = query.iterate(); iter.hasNext();) {
            WstColumnValue wcv = (WstColumnValue)iter.next();
            wstColumnValues.put(new WstColumnValueKey(wcv), wcv);
        }
    }
}
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