/**
    * Copyright 2004-2012 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 org.apache.torque.mojo;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileOutputStream;
  import java.io.IOException;
  
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.torque.mojo.morph.MorphRequest;
  import org.apache.torque.mojo.morph.Morpher;
  import org.codehaus.plexus.util.FileUtils;
  
  /**
   * Common logic for morphing one file to another file
   */
  public abstract class AbstractMorphSingleMojo extends BaseMojo {
  
  	/**
  	 * The artifactId (aka database schema)
  	 *
  	 * @parameter expression="${impex.artifactId}" default-value="${project.artifactId}"
  	 * @required
  	 */
  	private String artifactId;
  
  	/**
  	 * The file that will contain the morphed contents
  	 */
  	private File newFile;
  
  	/**
  	 * The file containing the contents to be morphed
  	 */
  	private File oldFile;
  
  	/**
  	 * Add logic to the basic skip() method for skipping based on a morph being needed
  	 */
  	@Override
  	protected boolean skipMojo() {
  		// We may be skipping based on packaging of type 'pom'
  		if (super.skipMojo()) {
  			return true;
  		}
  
  		// If a morph is needed, we can't skip
  		boolean morphNeeded = isMorphNeeded();
  		if (morphNeeded) {
  			return false;
  		} else {
  			getLog().info("Skipping morph.  Nothing has changed");
  			return true;
  		}
  	}
  
  	protected boolean isMorphNeeded() {
  		// The file they asked to morph does not exist
  		if (!getOldFile().exists()) {
  			getLog().debug("file:" + getOldFile().getAbsolutePath() + " does not exist");
  			return false;
  		}
  
  		// The new file does not exist, we need to morph
  		if (!getNewFile().exists()) {
  			return true;
  		}
  
  		// Extract the last modified timestamps
  		long oldLastModified = getOldFile().lastModified();
  		long newLastModified = getNewFile().lastModified();
  
  		// If old file has been modified since the new file was last modified,
  		// we need to morph
  		return oldLastModified > newLastModified;
  	}
  
  	protected abstract Morpher getMorpher(MorphRequest request, String artifactId);
  
  	@Override
  	protected void executeMojo() throws MojoExecutionException {
  		try {
  			getLog().info("From: " + oldFile.getAbsolutePath());
  			getLog().info("  To: " + newFile.getAbsolutePath());
  			FileUtils.forceMkdir(new File(FileUtils.getPath(newFile.getAbsolutePath())));
 			MorphRequest request = new MorphRequest(oldFile.getName(), new FileInputStream(oldFile), new FileOutputStream(newFile));
 			request.setEncoding(getEncoding());
 			Morpher morpher = getMorpher(request, artifactId);
 			morpher.executeMorph();
 		} catch (IOException e) {
 			throw new MojoExecutionException("Unexpected error while attempting to morph " + oldFile.getAbsolutePath(), e);
 		}
 	}
 
 	public File getNewFile() {
 		return newFile;
 	}
 
 	public void setNewFile(final File newFile) {
 		this.newFile = newFile;
 	}
 
 	public File getOldFile() {
 		return oldFile;
 	}
 
 	public void setOldFile(final File oldFile) {
 		this.oldFile = oldFile;
 	}
 
 	public String getArtifactId() {
 		return artifactId;
 	}
 
 	public void setArtifactId(String artifactId) {
 		this.artifactId = artifactId;
 	}
 }