/*
    * Copyright 2007 Werner Guttmann
    *
    * Licensed 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.
   */
  package org.castor.anttask;
  
  import java.io.File;
  import java.io.FileWriter;
  import java.io.IOException;
  import java.util.Vector;
  
  import org.apache.tools.ant.BuildException;
  import org.apache.tools.ant.DirectoryScanner;
  import org.apache.tools.ant.taskdefs.MatchingTask;
  import org.apache.tools.ant.types.FileSet;
  import org.exolab.castor.xml.schema.Schema;
  import org.exolab.castor.xml.schema.util.XMLInstance2Schema;
  import org.xml.sax.SAXException;
  
  /**
   * An <a href="http://ant.apache.org/">Ant</a> task to call the Castor {@link XMLInstance2Schema}
   * tool. It can be passed a file, a directory, a Fileset or all three.
   *
   * @author <a href="mailto:werner DOT guttmann AT gmx DOT net">Werner Guttmann</a>
   * @version $Revision: 6543 $ $Date: 2005-03-05 06:42:06 -0700 (Sat, 05 Mar 2005) $
   */
  public final class XMLInstance2SchemaTask extends MatchingTask {
      //--------------------------------------------------------------------------
  
      /** 
       * Error message -- no input provided. 
       */
      private static final String NO_XML_DOCUMENT_MSG =
          "At least one XML document instance must be provided.";
  
      //--------------------------------------------------------------------------
  
      /** 
      * Enlists the XML file to process. 
       */
      private File _xmlInstanceFile;
      
      /** 
       * Enlists a directory, for which the user wants to process all XML instance files. 
       **/
      private File _xmlInstanceDir;
      
      /** 
       * Enlists the fileset the user wants to process. 
       */
      private Vector _xmlInstanceFileSets = new Vector();
  
      // Begin application-specific parameters
      
      /** 
       * Name of the XML schema file to which the output should be written. 
       */
      private String _xmlSchemaFileName;
      
      /**
       * Default grouping to be <xsd:ALL/>.
       */
      private boolean _defaultGroupingAsAll;
      
      //--------------------------------------------------------------------------
  
      /**
       * Sets the individual schema that will have code generated for it.
       * 
       * @param file One schema file.
       */
      public void setFile(final File file) {
          _xmlInstanceFile = file;
      }
  
      /**
       * Sets the directory such that all schemas in this directory will have code
       * generated for them.
       * 
       * @param dir The directory containing schemas to process.
       */
      public void setDir(final File dir) {
          _xmlInstanceDir = dir;
      }
  
      /**
       * Adds a fileset to process that contains schemas to process.
       * 
      * @param set An individual file set containing schemas.
      */
     public void addFileset(final FileSet set) {
         _xmlInstanceFileSets.addElement(set);
     }
 
     /**
      * Specifies the name of the DDL file to be generated.
      * @param ddlFileName Name of the DDL file to be generated
      */
     public void setXmlSchemaFileName(final String ddlFileName) {
         _xmlSchemaFileName = ddlFileName;
     }
     
     /**
      * Specifies the default grouping to be <xsd:all/>.
      * @param defaultGroupingAsAll Default grouping to be used
      */
     public void setDefaultGrouping(final String defaultGroupingAsAll) {
         _defaultGroupingAsAll = true;
     }
 
     //--------------------------------------------------------------------------
 
     /**
      * Configured the code generator. If anything goes wrong during configuration of the
      * Ant task a BuildException will be thrown.
      */
     private void config() {
     }
 
     /**
      * Runs source generation. If anything goes wrong during source generation a
      * BuildException will be thrown.
      * 
      * @param filePath an individual Schema to generate code for.
      * @param outputFilePath Name of the output file to create.
      */
     private void processFile(final String filePath, final String outputFilePath) {
         log("Processing " + filePath);
         try {
             XMLInstance2Schema schemaGenerator = new XMLInstance2Schema();
             if (_defaultGroupingAsAll) {
                 schemaGenerator.setDefaultGroupingAsAll();
             }
             Schema schema = schemaGenerator.createSchema(filePath);
             String outputFileName = outputFilePath;
             if (outputFileName == null) {
                 outputFileName = deriveOutputFilePath(filePath);
             }
            FileWriter dstWriter = new FileWriter(outputFileName);
             schemaGenerator.serializeSchema(dstWriter, schema);
         } catch (IOException e) {
             throw new BuildException ("Problem writing to the given putput sink " 
                     + _xmlInstanceFile.getAbsolutePath(), e);
         } catch (SAXException e) {
             throw new BuildException ("Problem streaming the generated XML schema instance " 
                     + "to the given file.", e); 
         }
     }
 
     /**
      * Derives the XML schema file name from the XML instance document name.
      * @param outputFileName Name of the XML instance document.
      * @return The name of the XML schema instance.
      */
     private String deriveOutputFilePath(final String outputFileName) {
         return outputFileName + ".xsd";
     }
 
     /**
      * Public execute method -- entry point for the Ant task.  Loops over all
      * schema that need code generated and creates needed code generators, then
      * executes them. If anything goes wrong during execution of the Ant task a
      * BuildException will be thrown.
      * 
      * @see org.apache.tools.ant.Task#execute()
      */
     public void execute() {
         // Must have something to run the source generator on
         if (_xmlInstanceFile == null && _xmlInstanceDir == null 
                 && _xmlInstanceFileSets.size() == 0) {
             throw new BuildException(NO_XML_DOCUMENT_MSG);
         }
 
         config();
 
         // process just the file specified
         if (_xmlInstanceFile != null) {
             processFile(_xmlInstanceFile.getAbsolutePath(), _xmlSchemaFileName);
         }
 
         // process all files in the given directory
         if (_xmlInstanceDir != null && _xmlInstanceDir.exists() && _xmlInstanceDir.isDirectory()) {
             log("Given XML schema file name will be ignored.");
             DirectoryScanner ds = this.getDirectoryScanner(_xmlInstanceDir);
 
             String[] files = ds.getIncludedFiles();
             for (int i = 0; i < files.length; i++) {
                 String filePath = _xmlInstanceDir.getAbsolutePath() + File.separator + files[i];
                 processFile(filePath, null);
             }
         }
 
         // process all files of the given FileSet
         for (int i = 0; i < _xmlInstanceFileSets.size(); i++) {
             log("Given XML schema file name will be ignored.");
             FileSet fs = (FileSet) _xmlInstanceFileSets.elementAt(i);
             DirectoryScanner ds = fs.getDirectoryScanner(getProject());
             File subdir = fs.getDir(getProject());
 
             String[] files = ds.getIncludedFiles();
             for (int j = 0; j < files.length; j++) {
                 String filePath = subdir.getAbsolutePath() + File.separator + files[j];
                 processFile(filePath, null);
             }
         }
     }
 }