/*
    * 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 final Vector<FileSet> _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.add(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.isEmpty()) {
       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 (String file : files) {
         String filePath = _xmlInstanceDir.getAbsolutePath() + File.separator + file;
         processFile(filePath, null);
       }
     }
 
     // process all files of the given FileSet
     for (FileSet xmlInstanceFileSet : _xmlInstanceFileSets) {
       log("Given XML schema file name will be ignored.");
       FileSet fs = xmlInstanceFileSet;
       DirectoryScanner ds = fs.getDirectoryScanner(getProject());
       File subdir = fs.getDir(getProject());
 
       String[] files = ds.getIncludedFiles();
       for (String file : files) {
         String filePath = subdir.getAbsolutePath() + File.separator + file;
         processFile(filePath, null);
       }
     }
   }
 }