/*
    * Copyright 2005-2007 The Kuali Foundation
    *
    *
    * Licensed under the Educational Community 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.opensource.org/licenses/ecl2.php
   *
   * 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.
   */
  package com.rsmart.kuali.tools.liquibase;
  
  import java.io.IOException;
  import java.io.InputStream;
  
  import javax.xml.parsers.SAXParser;
  import javax.xml.parsers.SAXParserFactory;
  
  import liquibase.changelog.ChangeLogParameters;
  import liquibase.changelog.DatabaseChangeLog;
  import liquibase.exception.ChangeLogParseException;
  import liquibase.logging.LogFactory;
  import liquibase.parser.ChangeLogParser;
  import liquibase.parser.core.xml.*;
  import liquibase.resource.ResourceAccessor;
  import liquibase.util.file.FilenameUtils;
  
  import org.xml.sax.ErrorHandler;
  import org.xml.sax.InputSource;
  import org.xml.sax.SAXException;
  import org.xml.sax.SAXNotRecognizedException;
  import org.xml.sax.SAXNotSupportedException;
  import org.xml.sax.SAXParseException;
  import org.xml.sax.XMLReader;
  
  public class XMLChangeLogParser extends liquibase.parser.core.xml.XMLChangeLogSAXParser {
  
      public static String getSchemaVersion() {
          return "2.0";
      }
  
      public DatabaseChangeLog parse(String physicalChangeLogLocation, ChangeLogParameters changeLogParameters, ResourceAccessor resourceAccessor) throws ChangeLogParseException {
  
          InputStream inputStream = null;
          try {
              
              SAXParser parser = SAXParserFactory.newInstance().newSAXParser();
              try {
                  parser.setProperty("http://java.sun.com/xml/jaxp/properties/schemaLanguage", "http://www.w3.org/2001/XMLSchema");
              } catch (SAXNotRecognizedException e) {
                  //ok, parser must not support it
              } catch (SAXNotSupportedException e) {
                  //ok, parser must not support it
              }
  
              XMLReader xmlReader = parser.getXMLReader();
              LiquibaseEntityResolver resolver=new LiquibaseEntityResolver();
              resolver.useResoureAccessor(resourceAccessor,FilenameUtils.getFullPath(physicalChangeLogLocation));
              xmlReader.setEntityResolver(resolver);
              xmlReader.setErrorHandler(new ErrorHandler() {
                  public void warning(SAXParseException exception) throws SAXException {
                      LogFactory.getLogger().warning(exception.getMessage());
                      throw exception;
                  }
  
                  public void error(SAXParseException exception) throws SAXException {
                      LogFactory.getLogger().severe(exception.getMessage());
                      throw exception;
                  }
  
                  public void fatalError(SAXParseException exception) throws SAXException {
                      LogFactory.getLogger().severe(exception.getMessage());
                      throw exception;
                  }
              });
          	
              inputStream = resourceAccessor.getResourceAsStream(physicalChangeLogLocation);
              if (inputStream == null) {
                  throw new ChangeLogParseException(physicalChangeLogLocation + " does not exist");
              }
  
              XMLChangeLogSAXHandler contentHandler = new XMLChangeLogSAXHandler(physicalChangeLogLocation, resourceAccessor, changeLogParameters);
              xmlReader.setContentHandler(contentHandler);
              xmlReader.parse(new InputSource(inputStream));
  
              return contentHandler.getDatabaseChangeLog();
          } catch (ChangeLogParseException e) {
              throw e;
          } catch (IOException e) {
              throw new ChangeLogParseException("Error Reading Migration File: " + e.getMessage(), e);
          } catch (SAXParseException e) {
              throw new ChangeLogParseException("Error parsing line " + e.getLineNumber() + " column " + e.getColumnNumber() + " of " + physicalChangeLogLocation +": " + e.getMessage(), e);
          } catch (SAXException e) {
             Throwable parentCause = e.getException();
             while (parentCause != null) {
                 if (parentCause instanceof ChangeLogParseException) {
                     throw ((ChangeLogParseException) parentCause);
                 }
                 parentCause = parentCause.getCause();
             }
             String reason = e.getMessage();
             String causeReason = null;
             if (e.getCause() != null) {
                 causeReason = e.getCause().getMessage();
             }
 
 //            if (reason == null && causeReason==null) {
 //                reason = "Unknown Reason";
 //            }
             if (reason == null) {
                 if (causeReason != null) {
                     reason = causeReason;
                 } else {
                     reason = "Unknown Reason";
                 }
             }
 
             throw new ChangeLogParseException("Invalid Migration File: " + reason, e);
         } catch (Exception e) {
             throw new ChangeLogParseException(e);
         } finally {
             if (inputStream != null) {
                 try {
                     inputStream.close();
                 } catch (IOException e) {
                     // probably ok
                 }
             }
         }
     }
 }