package de.intevation.flys.artifacts.model;

import java.util.List;

import net.sf.ehcache.Cache;
import net.sf.ehcache.Element;

import de.intevation.flys.artifacts.cache.CacheFactory;

import de.intevation.flys.backend.SessionHolder;

import org.apache.log4j.Logger;

import de.intevation.flys.model.River;
import de.intevation.flys.model.Wst;

import org.hibernate.Session;
import org.hibernate.Query;
import org.hibernate.SQLQuery;

import org.hibernate.type.StandardBasicTypes;

public class WstValueTableFactory2
{
    private static Logger log = Logger.getLogger(WstValueTableFactory2.class);

    public static final int DEFAULT_KIND = 0;

    // TODO: put this into a property file

    public static final String HQL_WST =
        "from Wst where river=:river and kind=:kind";

    public static final String SQL_SELECT_NAMES_POS =
        "SELECT position, name FROM wst_columns " +
        "WHERE wst_id = :wst_id ORDER BY position";

    public static final String SQL_SELECT_QS =
        "SELECT column_pos, q, a, b FROM wst_q_values " +
        "WHERE wst_id = :wst_id";

    public static final String SQL_SELECT_WS =
        "SELECT km, w, column_pos FROM wst_w_values " +
        "WHERE wst_id = :wst_id";

    private WstValueTableFactory2() {
    }

    public static WstValueTable getTable(River river) {
        return getTable(river, DEFAULT_KIND);
    }

    public static WstValueTable getTable(River river, int kind) {

        Cache cache = CacheFactory.getCache(WstValueTableCacheKey.CACHE_NAME);

        WstValueTableCacheKey cacheKey;

        if (cache != null) {
            cacheKey = new WstValueTableCacheKey(river.getId(), kind);
            Element element = cache.get(cacheKey);
            if (element != null) {
                log.debug("got wst value table from cache");
                return (WstValueTable)element.getValue();
            }
        }
        else {
            cacheKey = null;
        }

        WstValueTable valueTable = getTableUncached(river, kind);

        if (valueTable != null && cacheKey != null) {
            log.debug("store wst value table in cache");
            Element element = new Element(cacheKey, valueTable);
            cache.put(element);
        }

        return valueTable;
    }

    public static WstValueTable getTableUncached(River river) {
        return getTableUncached(river, DEFAULT_KIND);
    }

    public static WstValueTable getTableUncached(River river, int kind) {

        Session session = SessionHolder.HOLDER.get();

        Query query = session.createQuery(HQL_WST);
        query.setParameter("river", river);
        query.setInteger("kind",    kind);

        List<Wst> wsts = query.list();

        if (wsts.isEmpty()) {
            return null;
        }

        Wst wst = wsts.get(0);

        SQLQuery sqlQuery = session.createSQLQuery(SQL_SELECT_NAMES_POS)
            .addScalar("position",   StandardBasicTypes.INTEGER)
            .addScalar("name",       StandardBasicTypes.STRING);

        sqlQuery.setInteger("wst_id", wst.getId());

        List<Object []> columnNames = sqlQuery.list();

        WstValueTable.Column [] columns =
            new WstValueTable.Column[columnNames.size()];

        for (int i = 0; i < columns.length; ++i) {
            columns[i] = new WstValueTable.Column(
                (String)columnNames.get(i)[1]);
        }

        sqlQuery = session.createSQLQuery(SQL_SELECT_QS)
            .addScalar("column_pos", StandardBasicTypes.INTEGER)
            .addScalar("q",          StandardBasicTypes.DOUBLE)
            .addScalar("a",          StandardBasicTypes.DOUBLE)
            .addScalar("b",          StandardBasicTypes.DOUBLE);

        sqlQuery.setInteger("wst_id", wst.getId());

        Integer lastColumn = null;

        List<Object []> qRanges = sqlQuery.list();
        int start = -1;

        int Q = qRanges.size();

        for (int i = 0; i < Q; ++i) {
            Object [] qRange = qRanges.get(i);
            Integer columnId = (Integer)qRange[0];
            if (lastColumn == null) {
                lastColumn = columnId;
                start = i;
            }
            else if (!lastColumn.equals(columnId)) {
                QRangeTree qRangeTree = new QRangeTree(qRanges, start, i);
                columns[lastColumn].setQRangeTree(qRangeTree);
                lastColumn = columnId;
                start = i;
            }
        }

        if (start != -1) {
            QRangeTree qRangeTree = new QRangeTree(qRanges, start, Q);
            columns[lastColumn].setQRangeTree(qRangeTree);
        }

        /* This is debug code to visualize the q ranges trees 

        java.io.PrintWriter out = null;
        try {
            out = new java.io.PrintWriter(
                new java.io.FileWriter(
                    "/tmp/qranges" + System.currentTimeMillis() + ".dot"));

            out.println("graph \"Q ranges trees\" {");

            for (int i = 0; i < columns.length; ++i) {
                QRangeTree tree = columns[i].getQRangeTree();
                out.println(tree.toGraph());
            }

            out.println("}");

            out.flush();
        }
        catch (java.io.IOException ioe) {
            log.error(ioe);
        }
        finally {
            if (out != null) {
                out.close();
            }
        }
        */
        // TODO: Implement me!

        return null;
    }
}
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