/*-
 * Copyright 2015 Diamond Light Source Ltd.
 *
 * 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
 */

package org.eclipse.dawnsci.nexus;

import java.io.File;

import org.eclipse.dawnsci.hdf5.nexus.NexusFileFactoryHDF5;
import org.eclipse.dawnsci.hdf5.nexus.NexusFileHDF5;

public class TestUtils {
	
	/**
	 * Prefix to folder in which test files are to be generated
	 */
	public static final String OUTPUT_FOLDER_PREFIX = "test-scratch/";
	
	/**
	 * Helper function to (recursively) delete a directory and all its contents
	 * 
	 * @param dir
	 *            - path to directory to delete
	 * @return - boolean True if directory no longer exists
	 */
	static boolean deleteDir(File dir) {
		if (!dir.exists()) {
			return true;
		}
		if (dir.isDirectory()) {
			String[] children = dir.list();
			for (String element : children) {
				boolean success = deleteDir(new File(dir, element));
				if (!success) {
					System.out.println("1. deleteDir could not delete: " + new File(dir, element));
					return false;
				}
			}
		}
		if (dir.delete()){
			return true;
		}
		System.out.println("2. deleteDir could not delete: " + dir +". Make sure each test creates a uniquely named folder. Otherwise stale NFS locks may prevent folder deletion.");
		return false;
	}

	/**
	 * Generates a (relative) directory name based on a class name. Uses the appropriate separators for the platform.
	 * 
	 * @param classname
	 *            - the name of the class on which to base the directory name (a value something like
	 *            "gda.analysis.io.JPEGTest").
	 * @return - the derived directory name.
	 */
	public static String generateDirectorynameFromClassname(String classname) {
		// the generated directory name is usable on both Linux and Windows
		// (which uses \ as a separator).
		return OUTPUT_FOLDER_PREFIX + classname.replace('.', '/') + '/';
		// File tmp = new File(OUTPUT_FOLDER_PREFIX + classname.replace('.',
		// '/') + '/');
		// return tmp.getAbsolutePath();
	}
	
	/**
	 * Creates an empty directory for use by test code. If the directory exists (from a previous test), the directory
	 * and all its contents are first deleted.
	 * 
	 * @param testScratchDirectoryname
	 *            - the name of the directory to create.
	 * @throws Exception
	 */
	public static void makeScratchDirectory(String testScratchDirectoryname) throws Exception {
		// delete any remains from a previous run of this test
		if (!deleteDir(new File(testScratchDirectoryname))) {
			throw new Exception("Unable to delete old test scratch directory " + testScratchDirectoryname);
		}
		// set up for a new run of this test
		if (!((new File(testScratchDirectoryname)).mkdirs())) {
			throw new Exception("Unable to create new test scratch directory " + testScratchDirectoryname);
		}
	}
}