package de.intevation.flys.artifacts;

import java.io.File;

import java.util.ArrayList;
import java.util.List;

import java.util.regex.Pattern;
import java.util.regex.Matcher;

import org.w3c.dom.Document;

import org.apache.log4j.Logger;

import org.hibernate.impl.SessionFactoryImpl;

import com.vividsolutions.jts.geom.Envelope;

import de.intevation.artifacts.Artifact;
import de.intevation.artifacts.ArtifactFactory;
import de.intevation.artifacts.CallMeta;

import de.intevation.artifacts.common.utils.FileTools;

import de.intevation.artifactdatabase.data.DefaultStateData;
import de.intevation.artifactdatabase.state.Facet;
import de.intevation.artifactdatabase.state.State;


import de.intevation.flys.backend.SessionFactoryProvider;

import de.intevation.flys.artifacts.resources.Resources;
import de.intevation.flys.artifacts.states.DefaultState;
import de.intevation.flys.artifacts.model.map.WMSDBLayerFacet;
import de.intevation.flys.utils.FLYSUtils;
import de.intevation.flys.utils.MapfileGenerator;


public abstract class WMSDBArtifact extends StaticFLYSArtifact {

    private static final Logger logger = Logger.getLogger(WMSDBArtifact.class);

    public static final Pattern DB_URL_PATTERN =
        Pattern.compile("(.*)\\/\\/(.*):([0-9]+)\\/([a-zA-Z]+)");

    public static final Pattern DB_PSQL_URL_PATTERN =
        Pattern.compile("(.*)\\/\\/(.*):([0-9]+)\\/([a-zA-Z0-9]+)");


    @Override
    public void setup(
        String          identifier,
        ArtifactFactory factory,
        Object          context,
        CallMeta        callMeta,
        Document        data)
    {
        logger.debug("WMSDBArtifact.setup");

        super.setup(identifier, factory, context, callMeta, data);

        String ids = getDatacageIDValue(data);

        if (ids != null && ids.length() > 0) {
            addData("ids", new DefaultStateData("ids", null, null, ids));
        }
        else {
            throw new IllegalArgumentException("No attribute 'ids' found!");
        }

        List<Facet> fs = new ArrayList<Facet>();

        WMSDBState state = (WMSDBState) getCurrentState(context);
        state.computeInit(this, hash(), context, callMeta, fs);

        if (!fs.isEmpty()) {
            addFacets(getCurrentStateId(), fs);
        }
    }


    @Override
    protected void initialize(
        Artifact artifact,
        Object   context,
        CallMeta callMeta)
    {
        // do nothing
    }


    @Override
    protected State getState(Object context, String stateID) {
        return getCurrentState(context);
    }


    /**
     * Get a list containing the one and only State.
     * @param  context ignored.
     * @return list with one and only state.
     */
    @Override
    protected List<State> getStates(Object context) {
        ArrayList<State> states = new ArrayList<State>();
        states.add(getCurrentState(context));

        return states;
    }



    public static abstract class WMSDBState extends DefaultState {
        private static final Logger logger = Logger.getLogger(WMSDBState.class);

        protected FLYSArtifact artifact;

        protected String name;
        protected int    riverId;


        public WMSDBState() {}

        public WMSDBState(FLYSArtifact artifact) {
            this.artifact = artifact;
            this.name     = null;
            this.riverId  = 0;
        }

        @Override
        public Object computeInit(
            FLYSArtifact artifact,
            String       hash,
            Object       context,
            CallMeta     meta,
            List<Facet>  facets
        ) {
            logger.debug("WMSDBState.computeInit");

            String type = getFacetType();

            WMSDBLayerFacet facet = new WMSDBLayerFacet(
                0,
                type,
                getTitle(meta),
                ComputeType.INIT,
                getID(), hash,
                getUrl());

            String name = type + "-" + artifact.identifier();

            facet.addLayer(name);
            facet.setExtent(getExtent());
            facet.setOriginalExtent(getExtent(true));
            facet.setSrid(getSrid());
            facet.setData(getDataString());
            facet.setFilter(getFilter());
            facet.setGeometryType(getGeometryType());
            facet.setConnection(getConnection());
            facet.setConnectionType(getConnectionType());
            facet.setLabelItem(getLabelItem());

            facets.add(facet);

            return null;
        }

        /**
         * This method returns a connection string for databases used by
         * Mapserver's Mapfile.
         *
         * @return A connection string for Mapserver.
         */
        protected String getConnection() {
            SessionFactoryImpl sf = (SessionFactoryImpl)
                SessionFactoryProvider.getSessionFactory();

            String user = SessionFactoryProvider.getUser(sf);
            String pass = SessionFactoryProvider.getPass(sf);
            String url  = SessionFactoryProvider.getURL(sf);

            logger.debug("Parse connection url: " + url);

            Matcher m = DB_URL_PATTERN.matcher(url);
            if (!m.matches()) {
                logger.warn("Could not parse Connection string." +
                	"Try to parse PostgreSQL string.");
                // maybe this is a PostgreSQL connection...
                return getPostgreSQLConnection();
            }

            logger.debug("Groups for connection string: " + m.groupCount());
            int groups = m.groupCount();

            for (int i = 0; i <= groups; i++) {
                logger.debug("Group " + i + ": " + m.group(i));
            }

            String connection = null;

            if (FLYSUtils.isUsingOracle()) {
                if (groups < 3) {
                    logger.warn("Could only partially parse connection string.");
                    return null;
                }

                String host = m.group(2);
                String port = m.group(3);

                connection = user + "/" + pass + "@" + host;
            }
            else {
                if (groups < 4) {
                    logger.warn("Could only partially parse connection string.");
                    return null;
                }

                String host = m.group(2);
                String port = m.group(3);
                String db   = m.group(4);

                StringBuilder sb = new StringBuilder();
                sb.append("dbname=" + db);
                sb.append("host='" + host + "'");
                sb.append("port=" + port);
                sb.append("password='" + pass + "'");
                sb.append("sslmode=disable");

                connection = sb.toString();
            }

            logger.debug("Created connection: '" + connection + "'");

            return connection;
        }

        protected String getPostgreSQLConnection() {
            SessionFactoryImpl sf = (SessionFactoryImpl)
                SessionFactoryProvider.getSessionFactory();

            String user = SessionFactoryProvider.getUser(sf);
            String pass = SessionFactoryProvider.getPass(sf);
            String url  = SessionFactoryProvider.getURL(sf);

            Matcher m = DB_PSQL_URL_PATTERN.matcher(url);
            if (!m.matches()) {
                logger.warn("Could not parse PostgreSQL Connection string.");
                return null;
            }

            int groups = m.groupCount();
            logger.debug("Groups for PostgreSQL connection string: " + groups);

            if (logger.isDebugEnabled()) {
                for (int i = 0; i <= groups; i++) {
                    logger.debug("Group " + i + ": " + m.group(i));
                }
            }

            String connection = null;

            if (groups < 4) {
                logger.warn("Could only partially parse connection string.");
                return null;
            }

            String host = m.group(2);
            String port = m.group(3);
            String db   = m.group(4);

            StringBuilder sb = new StringBuilder();
            sb.append("dbname=" + db);
            sb.append(" host='" + host + "'");
            sb.append(" port=" + port);
            sb.append(" user=" + user);
            sb.append(" password='" + pass + "'");
            sb.append(" sslmode=disable");

            connection = sb.toString();

            logger.debug("Created connection: '" + connection + "'");

            return connection;
        }

        protected String getConnectionType() {
            return FLYSUtils.isUsingOracle() ? "oraclespatial" : "postgis";
        }

        protected String getLabelItem() {
            return null;
        }

        public int getRiverId() {
            if (riverId == 0) {
                String   ids   = artifact.getDataAsString("ids");
                String[] parts = ids.split(";");

                try {
                    riverId = Integer.parseInt(parts[0]);
                }
                catch (NumberFormatException nfe) {
                    logger.error("Cannot parse river id from '" + parts[0] + "'");
                }
            }

            return riverId;
        }

        /**
         * Returns the name of the WMS layer. This method extracts the name
         * from 'ids' data string. It is expected, that the 'ids' string is
         * seperated by ';' and that the name is placed at index 1.
         *
         * @return the name of the WMS layer.
         */
        public String getName() {
            if (name == null) {
                String ids = artifact.getDataAsString("ids");

                String parts[] = ids != null ? ids.split(";") : null;

                if (parts != null && parts.length >= 2) {
                    name = parts[1];
                }
            }

            return name;
        }


        /**
         * Returns the name of the layer (returned by getName()) or the layer
         * type if the name is empty. The layer type is created by an i18n
         * string of getFacetType().
         *
         * @param meta A CallMeta used for i18n.
         *
         * @return the name of the layer or its type if name is empty.
         */
        protected String getTitle(CallMeta meta) {
            String name = getName();

            return name != null && name.length() > 0
                ? name
                : Resources.getMsg(
                    meta,
                    getFacetType(),
                    getFacetType());
        }


        @Override
        public void endOfLife(Artifact owner, Object context) {
            logger.info("Destroy WMSDBState: " + getID());

            String p = FLYSUtils.getXPathString(FLYSUtils.XPATH_SHAPEFILE_DIR);
            File dir = new File(p, owner.identifier());

            if (dir != null && dir.exists()) {
                logger.debug("Try to delete directory '" + dir + "'");

                FileTools.deleteRecursive(dir);
                MapfileGenerator.getInstance().update();
            }
        }

        /**
         * This method returns the extent of a DB layer in the projection of the
         * database.
         *
         * @return the extent of the DB layer in the projection of the database.
         */
        protected Envelope getExtent() {
            return getExtent(false);
        }


        protected abstract String getFacetType();

        protected abstract String getUrl();

        protected abstract String getSrid();

        /**
         * This method returns the extent of the DB layer. The projection of the
         * extent depends on the <i>reproject</i> parameter. If reproject is set,
         * the extent is reprojected into the original projection which is
         * specified in the configuration. Otherwise, the projection of the
         * database is used.
         *
         * @param reproject True, to reproject the extent into the projection
         * specified in the configuration.
         *
         * @return the extent of the database layer.
         */
        protected abstract Envelope getExtent(boolean reproject);

        protected abstract String getFilter();

        protected abstract String getDataString();

        protected abstract String getGeometryType();
    } // end of WMSDBState
}
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