package org.apache.torque.engine.database.transform;

 /*

  * Licensed to the Apache Software Foundation (ASF) under one

  * or more contributor license agreements.  See the NOTICE file

  * distributed with this work for additional information

  * regarding copyright ownership.  The ASF licenses this file

  * to you under the Apache License, Version 2.0 (the

  * "License"); you may not use this file except in compliance

  * with the License.  You may obtain a copy of the License at

  *

  *   http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing,

  * software distributed under the License is distributed on an

  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY

  * KIND, either express or implied.  See the License for the

  * specific language governing permissions and limitations

  * under the License.

  */

 import java.io.BufferedInputStream;

 import java.io.BufferedReader;

 import java.io.File;

 import java.io.FileInputStream;

 import java.io.FileReader;

 import java.io.IOException;

 import java.io.Reader;

 import java.net.MalformedURLException;

 import java.net.URL;

 import java.util.ArrayList;

 import java.util.List;

 import javax.xml.parsers.SAXParser;

 import javax.xml.parsers.SAXParserFactory;

 import org.apache.commons.lang.StringUtils;

 import org.apache.commons.logging.Log;

 import org.apache.commons.logging.LogFactory;

 import org.apache.torque.engine.database.model.Column;

 import org.apache.torque.engine.database.model.Database;

 import org.apache.torque.engine.database.model.Table;

 import org.xml.sax.Attributes;

 import org.xml.sax.EntityResolver;

 import org.xml.sax.InputSource;

 import org.xml.sax.SAXException;

 import org.xml.sax.helpers.DefaultHandler;

 /**

  * A Class that is used to parse an input xml schema file and creates and AppData java structure.

  * 

  * @author <a href="mailto:leon@opticode.co.za">Leon Messerschmidt</a>

  * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>

  * @author <a href="mailto:mpoeschl@marmot.at">Martin Poeschl</a>

  * @author <a href="mailto:fedor.karpelevitch@home.com">Fedor Karpelevitch</a>

  * @version $Id: XmlToData.java,v 1.1 2007-10-21 07:57:26 abyrne Exp $

  */

 public class XmlToData extends DefaultHandler implements EntityResolver {

         /** Logging class from commons.logging */

         private static Log log = LogFactory.getLog(XmlToData.class);

         private Database database;

         private List<Object> data;

         private File dtdFile;

         private static SAXParserFactory saxFactory;

         static {

                 saxFactory = SAXParserFactory.newInstance();

                 saxFactory.setValidating(true);

         }

         /**

          * Default custructor

          */

         public XmlToData(Database database, String dtdFilePath) throws MalformedURLException, IOException {

                 this.database = database;

                 this.dtdFile = new File(dtdFilePath);

         }

         /**

      *

      */

         public List<?> parseFile(String xmlFile) throws Exception {

                 data = new ArrayList<Object>();

                 SAXParser parser = saxFactory.newSAXParser();

                 Reader r = new BufferedReader(new FileReader(xmlFile));

                 try {

                         InputSource is = new InputSource(r);

                         is.setSystemId(dtdFile.getAbsolutePath());

                         parser.parse(is, this);

                 } finally {

                         r.close();

                 }

                 return data;

         }

         /**

          * Handles opening elements of the xml file.

          */

         public void startElement(String uri, String localName, String rawName, Attributes attributes) throws SAXException {

                 try {

                         if (rawName.equals("dataset")) {

                                 // ignore <dataset> for now.

                         } else {

                                 Table table = database.getTableByJavaName(rawName);

                                 if (table == null) {

                                         throw new SAXException("Table '" + rawName + "' unknown");

                                 }

                                 List<ColumnValue> columnValues = new ArrayList<ColumnValue>();

                                 for (int i = 0; i < attributes.getLength(); i++) {

                                         Column col = table.getColumnByJavaName(attributes.getQName(i));

                                         if (col == null) {

                                                 throw new SAXException("Column " + attributes.getQName(i) + " in table " + rawName + " unknown.");

                                         }

                                         String value = attributes.getValue(i);

                                         columnValues.add(new ColumnValue(col, value));

                                 }

                                 data.add(new DataRow(table, columnValues));

                         }

                 } catch (Exception e) {

                         throw new SAXException(e);

                 }

         }

         /**

          * called by the XML parser

          * 

          * @return an InputSource for the database.dtd file

          */

         public InputSource resolveEntity(String publicId, String systemId) throws SAXException {

                 try {

                         File systemIdFile = new File(systemId);

                         if (dtdFile.equals(systemIdFile)) {

                                 log.debug("Resolver: -> used " + dtdFile.getPath());

                                 return new InputSource(new BufferedInputStream(new FileInputStream(dtdFile)));

                         } else {

                                 log.debug("Resolver: -> used " + systemId);

                                 return getInputSource(systemId);

                         }

                 } catch (IOException e) {

                         throw new SAXException(e);

                 }

         }

         /**

          * get an InputSource for an URL String

          * 

          * @param urlString

          * @return an InputSource for the URL String

          */

         public InputSource getInputSource(String urlString) throws IOException {

                 URL url = new URL(urlString);

                 InputSource src = new InputSource(url.openStream());

                 return src;

         }

         /**

      *

      */

         public class DataRow {

                 private Table table;

                 private List<ColumnValue> columnValues;

                 public DataRow(Table table, List<ColumnValue> columnValues) {

                         this.table = table;

                         this.columnValues = columnValues;

                 }

                 public Table getTable() {

                         return table;

                 }

                 public List<?> getColumnValues() {

                         return columnValues;

                 }

         }

         /**

      *

      */

         public class ColumnValue {

                 private Column col;

                 private String val;

                 public ColumnValue(Column col, String val) {

                         this.col = col;

                         this.val = val;

                 }

                 public Column getColumn() {

                         return col;

                 }

                 public String getValue() {

                         return val;

                 }

                 public String getEscapedValue() {

                         StringBuffer sb = new StringBuffer();

                         sb.append("'");

                         sb.append(StringUtils.replace(val, "'", "''"));

                         sb.append("'");

                         return sb.toString();

                 }

         }

 }