ScriptSaver.java

/*******************************************************************************
 * Copyright (c) 2006-2015
 * Software Technology Group, Dresden University of Technology
 * DevBoost GmbH, Dresden, Amtsgericht Dresden, HRB 34001
 * 
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * 
 * Contributors:
 *   Software Technology Group - TU Dresden, Germany;
 *   DevBoost GmbH - Dresden, Germany
 *      - initial API and implementation
 ******************************************************************************/
package de.devboost.buildboost.util;

import static de.devboost.buildboost.IConstants.ARTIFACTS_FOLDER;
import static de.devboost.buildboost.IConstants.BUILD_BOOST_BIN_FOLDER;
import static de.devboost.buildboost.IConstants.BUILD_BOOST_CORE_PROJECT_ID;
import static de.devboost.buildboost.IConstants.PROJECTS_FOLDER;

import java.io.File;
import java.io.FileWriter;
import java.io.IOException;
import java.util.List;

import de.devboost.buildboost.BuildException;
import de.devboost.buildboost.BuildScriptGeneratorRunner;
import de.devboost.buildboost.ant.AntScript;
import de.devboost.buildboost.ant.AntTarget;
import de.devboost.buildboost.model.IBuildStage;

/**
 * The {@link ScriptSaver} class can be used to save the script generated by build stages to disc.
 */
public class ScriptSaver {

	/**
	 * Creates one build script for each build stage and a master script that calls the stages subsequently. All script
	 * are saved in the given target directory and using names.
	 * 
	 * @param targetDir
	 *            the directory where to save the scripts
	 * @param stages
	 *            the stages used to obtain the scripts
	 * @throws BuildException
	 *             thrown if something goes wrong while generating build scripts
	 */
	public void saveStages(File targetDir, List<IBuildStage> stages) throws BuildException {
		// first save scripts for stages
		int stageNumber = 1;
		for (IBuildStage stage : stages) {
			String fileName = getStageFileName(stageNumber);
			saveStage(targetDir, stage, fileName);
			stageNumber++;
		}
		saveMasterScript(targetDir, stages);
	}

	public void saveMasterScript(File targetDir, List<IBuildStage> stages) throws BuildException {
		// then create master script that calls the scripts for the stages
		AntScript masterScript = new AntScript();
		masterScript.setName("BuildBoostMaster");
		XMLContent content = new XMLContent();
		int lastStageNumber = stages.size() + 1;
		for (int i = 1; i < lastStageNumber; i++) {
			IBuildStage stage = stages.get(i - 1);
			if (stage.isEnabled()) {
				content.append("<ant antfile=\"" + getStageFileName(i) + "\" />");
			} else {
				content.append("<echo message=\"Build stage " + i + " is disabled and will not be executed.\" />");
			}
			if (i < lastStageNumber - 1) {
				// we must regenerate the build scripts after each stage,
				// because stages can rely on the output of the previous one.
				content.append("<echo message=\"Regenerate build scripts (to consider changes from previous build stage)\" />");
				// TODO put this into a macro
				content.append("<echo message=\"Run custom script generator via script runner\" />");
				content.append("<java fork=\"true\" classname=\"" + BuildScriptGeneratorRunner.class.getName()
						+ "\" failonerror=\"true\">");
				content.append("<arg value=\"${workspace}\" />");
				content.append("<arg value=\"${build_plugin_id}.BuildScriptGenerator\"/>");

				content.append("<classpath>");
				content.append("<pathelement path=\"${basedir}/" + ARTIFACTS_FOLDER + "/" + PROJECTS_FOLDER + "/"
						+ BUILD_BOOST_CORE_PROJECT_ID + "\" />");
				content.append("<pathelement path=\"${basedir}/" + BUILD_BOOST_BIN_FOLDER + "\" />");
				content.append("<pathelement path=\"${java.class.path}\"/>");
				content.append("</classpath>");
				content.append("<jvmarg value=\"-DBUILD_BOOST_IGNORE_STAGES=${BUILD_BOOST_IGNORE_STAGES}\"/>");
				content.append("</java>");
			}
		}
		AntTarget masterTarget = new AntTarget("buildboost-master", content);
		masterScript.addTarget(masterTarget);
		// save master script that calls all the stage scripts
		save(targetDir, masterScript.getScript(), "buildboost_master.xml");
	}

	public void saveStage(File targetDir, IBuildStage stage, String fileName) throws BuildException {
		AntScript script = stage.getScript();
		save(targetDir, script.getScript(), fileName);
	}

	/**
	 * Returns an auto-generated name for the build stage with the given index.
	 * 
	 * @param stageNumber
	 *            the index of the build stage
	 * @return a file name that is unique for each index
	 */
	public String getStageFileName(int stageNumber) {
		return "buildboost_stage_" + stageNumber + ".xml";
	}

	/**
	 * Saves the given content to a file.
	 * 
	 * @param targetDir
	 *            the directory to save the file to
	 * @param content
	 *            the content to save
	 * @param fileName
	 *            the name of the file to save
	 * 
	 * @throws BuildException
	 *             if something goes wrong
	 */
	private void save(File targetDir, String content, String fileName) throws BuildException {
		if (!targetDir.exists()) {
			boolean success = targetDir.mkdirs();
			if (!success) {
				throw new BuildException("Can't create directory '" + targetDir + "'.");
			}
		}

		try {
			FileWriter writer = new FileWriter(new File(targetDir.getAbsolutePath() + File.separator + fileName));
			writer.append(content);
			writer.close();
		} catch (IOException e) {
			throw new BuildException("IOException while saving script '" + fileName + "' (" + e.getMessage() + ").");
		}
	}
}