/**
    * Copyright 2006-2012 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.io.OutputStream;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.apache.commons.io.FileUtils;
  import org.apache.commons.io.IOUtils;
  import org.apache.commons.lang.StringUtils;
  import org.apache.maven.plugin.AbstractMojo;
  import org.apache.maven.plugin.MojoExecutionException;
  import org.apache.torque.util.SimpleScanner;
  
  /**
   * Examine SQL files and convert them to always use the delimiter <code>/</code> on it's own line. Convert any lines ending with
   * <code>;</code> to use a <code>/</code> on it's own line.
   *
   * @goal convertsql
   */
  public class ConvertSQLMojo extends AbstractMojo {
  	private static final String FS = File.separator;
  
  	/**
  	 * The encoding to use when reading/writing files
  	 *
  	 * @parameter expression="${impex.encoding}" default-value="${project.build.sourceEncoding}"
  	 */
  	private String encoding;
  
  	/**
  	 * The old delimiter used to terminate a SQL statement by being present at the end of a line.
  	 *
  	 * @parameter expression="${impex.oldDelimiter}" default-value=";"
  	 * @required
  	 */
  	private String oldDelimiter;
  
  	/**
  	 * The new delimiter to put on its own line
  	 *
  	 * @parameter expression="${impex.newDelimiter}" default-value="/"
  	 * @required
  	 */
  	private String newDelimiter;
  
  	/**
  	 * Directory to examine for .sql files
  	 *
  	 * @parameter expression="${impex.sourceDir}" default-value="${project.build.directory}/sql/source"
  	 * @required
  	 */
  	private File sourceDir;
  
  	/**
  	 * Directory to generate the converted files into
  	 *
  	 * @parameter expression="${impex.outputDir}" default-value="${project.build.directory}/sql/output"
  	 * @required
  	 */
  	private File outputDir;
  
  	/**
  	 * Files to include
  	 *
  	 * @parameter expression="${impex.includes}" default-value="*.sql"
  	 */
  	private String includes;
  
  	/**
  	 * Files to exclude
  	 *
  	 * @parameter expression="${impex.excludes}"
  	 */
  	private String excludes;
  
  	/**
  	 * Liquibase injects a handful of metadata at the top of each SQL file that causes "noise". All of the checksums and actual SQL may stay
  	 * the same, but the Liquibase metadata makes it appear as though the resulting SQL file has changed. By omitting the metadata you can
  	 * run the same change set multiple times and get the exact same SQL file as output. This makes it much easier to perform validation
  	 * checks on the SQL.
  	 *
  	 * @parameter expression="${impex.skipIrrelevantLiquibaseMetadataLines}" default-value="false"
 	 */
 	private boolean skipIrrelevantLiquibaseMetadataLines;
 
 	@Override
 	public void execute() throws MojoExecutionException {
 		try {
 			List<File> files = getFiles();
 			if (files == null || files.size() == 0) {
 				getLog().info("No files found");
 				return;
 			}
 			getLog().info("Found " + files.size() + " SQL files to convert");
 			convert(files);
 		} catch (Exception e) {
 			throw new MojoExecutionException("Unexpected error", e);
 		}
 	}
 
 	protected void convert(List<File> files) throws IOException {
 		for (File file : files) {
 			convert(file);
 		}
 	}
 
 	protected List<String> getLiquibaseTokens() {
 		List<String> tokens = new ArrayList<String>();
 		tokens.add("-- Ran at:");
 		tokens.add("-- Against:");
 		tokens.add("-- Liquibase version:");
 		tokens.add("--  Ran at:");
 		tokens.add("--  Against:");
 		tokens.add("--  Liquibase version:");
 		return tokens;
 	}
 
 	protected boolean isSkipLine(String line) {
 		if (!skipIrrelevantLiquibaseMetadataLines) {
 			return false;
 		}
 		List<String> tokens = getLiquibaseTokens();
 		for (String token : tokens) {
 			if (line.startsWith(token)) {
 				return true;
 			}
 		}
 		return false;
 	}
 
 	protected void convert(File file) throws IOException {
 		String outputFilename = outputDir + FS + file.getName();
 		File outputFile = new File(outputFilename);
 		@SuppressWarnings("unchecked")
 		List<String> lines = FileUtils.readLines(file, encoding);
 		getLog().info("Creating " + outputFile.getCanonicalPath());
 		OutputStream out = null;
 		try {
 			out = FileUtils.openOutputStream(outputFile);
 			for (String line : lines) {
 				if (isSkipLine(line)) {
 					continue;
 				}
 				String convertedLine = getConvertedLine(line);
 				out.write(convertedLine.getBytes(encoding));
 			}
 		} finally {
 			IOUtils.closeQuietly(out);
 		}
 	}
 
 	protected String getConvertedLine(String line) {
 		String trimmed = StringUtils.trim(line);
 		if (trimmed.endsWith(oldDelimiter)) {
 			int pos = line.lastIndexOf(oldDelimiter);
 			return line.substring(0, pos) + IOUtils.LINE_SEPARATOR_UNIX + newDelimiter + IOUtils.LINE_SEPARATOR_UNIX;
 		} else {
 			return line + IOUtils.LINE_SEPARATOR_UNIX;
 		}
 	}
 
 	protected List<File> getFiles() throws IOException {
 		FileUtils.forceMkdir(sourceDir);
 		getLog().info("Examining " + sourceDir.getCanonicalPath());
 		SimpleScanner scanner = new SimpleScanner(sourceDir, includes, excludes);
 		return scanner.getFiles();
 	}
 
 	public File getSourceDir() {
 		return sourceDir;
 	}
 
 	public void setSourceDir(File inputDir) {
 		this.sourceDir = inputDir;
 	}
 
 	public File getOutputDir() {
 		return outputDir;
 	}
 
 	public void setOutputDir(File outputDir) {
 		this.outputDir = outputDir;
 	}
 
 	public String getIncludes() {
 		return includes;
 	}
 
 	public void setIncludes(String includes) {
 		this.includes = includes;
 	}
 
 	public String getExcludes() {
 		return excludes;
 	}
 
 	public void setExcludes(String excludes) {
 		this.excludes = excludes;
 	}
 
 	public String getEncoding() {
 		return encoding;
 	}
 
 	public void setEncoding(String encoding) {
 		this.encoding = encoding;
 	}
 
 	public String getOldDelimiter() {
 		return oldDelimiter;
 	}
 
 	public void setOldDelimiter(String oldDelimiter) {
 		this.oldDelimiter = oldDelimiter;
 	}
 
 	public String getNewDelimiter() {
 		return newDelimiter;
 	}
 
 	public void setNewDelimiter(String newDelimiter) {
 		this.newDelimiter = newDelimiter;
 	}
 
 	public boolean isSkipIrrelevantLiquibaseMetadataLines() {
 		return skipIrrelevantLiquibaseMetadataLines;
 	}
 
 	public void setSkipIrrelevantLiquibaseMetadataLines(boolean skipIrrelevantLiquibaseMetadataLines) {
 		this.skipIrrelevantLiquibaseMetadataLines = skipIrrelevantLiquibaseMetadataLines;
 	}
 
 }