/**
    * 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.IOException;
  import java.util.ArrayList;
  import java.util.Collection;
  import java.util.Collections;
  import java.util.List;
  
  import org.apache.commons.io.FileUtils;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.maven.plugin.MojoFailureException;
  
  /**
   * Examine the directory that SQL files were generated to and produce a file that contains a listing of any tables that contained data at
   * the point in time the export was run.
   *
   * @goal generatetablelisting
   */
  public class GenerateTableListingMojo extends BaseMojo {
  	private static final String FS = File.separator;
  
  	/**
  	 * The extension for SQL files
  	 *
  	 * @parameter expression="${impex.extension}" default-value="sql"
  	 * @required
  	 */
  	private String extension;
  
  	/**
  	 * The database vendor being targeted
  	 *
  	 * @parameter expression="${impex.targetDatabase}"
  	 * @required
  	 */
  	private String targetDatabase;
  
  	/**
  	 * The directory where SQL is being generated - <code>targetDatabase</code> is automatically appended to this value
  	 *
  	 * @parameter expression="${impex.baseSqlDir}" default-value="${project.build.directory}/impex/sql"
  	 * @required
  	 */
  	private File baseSqlDir;
  
  	/**
  	 * The artifactId (aka "schema") for this set of impex data
  	 *
  	 * @parameter expression="${impex.artifactId}" default-value="${project.artifactId}"
  	 * @required
  	 */
  	private String artifactId;
  
  	@Override
  	protected void executeMojo() throws MojoExecutionException, MojoFailureException {
  		File databaseSQLDir = new File(baseSqlDir, targetDatabase);
  		if (!databaseSQLDir.exists()) {
  			throw new MojoExecutionException(databaseSQLDir + " does not exist");
  		}
  		getLog().info("Examining " + databaseSQLDir);
  		List<File> files = getFileListing(databaseSQLDir);
  		getLog().info("Located " + files.size() + " " + extension + " files");
  		List<String> tableNames = getTableNames(files);
  		List<String> locations = getLocations(tableNames);
  		getLog().info("Located " + tableNames.size() + " tables");
  		try {
  			String outputFilename = databaseSQLDir.getAbsolutePath() + FS + ".." + FS + ".." + FS + "META-INF" + FS + targetDatabase + FS + artifactId + ".tables";
  			File outputFile = new File(outputFilename);
  			getLog().info("Generating " + outputFile.getCanonicalPath());
  			FileUtils.writeLines(outputFile, locations);
  		} catch (IOException e) {
  			throw new MojoExecutionException("Unexpected IO error", e);
  		}
  	}
  
  	protected List<String> getLocations(List<String> tableNames) {
  		List<String> locations = new ArrayList<String>();
  		for (String tableName : tableNames) {
  			locations.add("classpath:sql/" + targetDatabase + "/" + tableName + ".sql");
  		}
  		return locations;
  	}
  
 	@SuppressWarnings("unchecked")
 	protected List<File> getFileListing(File dir) {
 		String[] extensions = new String[] { extension };
 		Collection<File> files = FileUtils.listFiles(dir, extensions, false);
 		List<File> fileList = new ArrayList<File>();
 		if (files != null) {
 			fileList.addAll(files);
 		}
 		return fileList;
 	}
 
 	protected List<String> getTableNames(List<File> files) {
 		String[] skipTokens = new String[] { artifactId + "." + extension, artifactId + "-constraints." + extension };
 		List<String> tableNames = new ArrayList<String>();
 		for (File file : files) {
 			if (isSkip(file, skipTokens)) {
 				continue;
 			}
 			String fragment = file.getName();
 			int beginIndex = 0;
 			int endIndex = fragment.length() - (extension.length() + 1);
 			String fragmentMinusExtension = fragment.substring(beginIndex, endIndex);
 			tableNames.add(fragmentMinusExtension);
 		}
 		Collections.sort(tableNames);
 		return tableNames;
 	}
 
 	protected boolean isSkip(File file, String[] skipTokens) {
 		String path = file.getAbsolutePath();
 		for (String skipToken : skipTokens) {
 			if (path.endsWith(skipToken)) {
 				return true;
 			}
 		}
 		return false;
 	}
 
 	public String getExtension() {
 		return extension;
 	}
 
 	public void setExtension(String extension) {
 		this.extension = extension;
 	}
 
 	public String getTargetDatabase() {
 		return targetDatabase;
 	}
 
 	public void setTargetDatabase(String targetDatabase) {
 		this.targetDatabase = targetDatabase;
 	}
 
 	public String getArtifactId() {
 		return artifactId;
 	}
 
 	public void setArtifactId(String artifactId) {
 		this.artifactId = artifactId;
 	}
 
 	public File getBaseSqlDir() {
 		return baseSqlDir;
 	}
 
 	public void setBaseSqlDir(File sqlDir) {
 		this.baseSqlDir = sqlDir;
 	}
 
 }