/*
 * Copyright 2006 the original author or authors.
 * 
 * Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0
 * 
 * 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.wamblee.test;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.net.URL;
import java.net.URLDecoder;
import java.security.CodeSource;

import junit.framework.TestCase;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import sun.security.krb5.internal.crypto.b;

/**
 * File system utilities.
 */
public final class FileSystemUtils {

    private static final Log LOG = LogFactory.getLog(FileSystemUtils.class);

    /**
     * Test output directory relative to the sub project.
     */
    private static final String TEST_OUTPUT_DIR = "resources/testoutput";

    /*
     * Disabled.
     * 
     */
    private FileSystemUtils() {
        // Empty
    }

    /**
     * Deletes a directory recursively. The test case will fail if the directory
     * does not exist or if deletion fails.
     * 
     * @param aDir
     *            Directory to delete.
     */
    public static void deleteDirRecursively(String aDir) {
        deleteDirRecursively(new File(aDir));
    }

    /**
     * Deletes a directory recursively. See {@link #deleteDirRecursively}.
     * 
     * @param aDir
     *            Directory.
     */
    public static void deleteDirRecursively(File aDir) {
        TestCase.assertTrue(aDir.isDirectory());

        for (File file : aDir.listFiles()) {
            if (file.isDirectory()) {
                deleteDirRecursively(file);
            } else {
                delete(file);
            }
        }

        delete(aDir);
    }

    /**
     * Deletes a file or directory. The test case will fail if the file or
     * directory does not exist or if deletion fails. Deletion of a non-empty
     * directory will always fail.
     * 
     * @param aFile
     *            File or directory to delete.
     */
    public static void delete(File aFile) {
        TestCase.assertTrue(aFile.delete());
    }

    /**
     * Gets a path relative to a sub project. This utility should be used to
     * easily access file paths within a subproject without requiring any
     * specific Eclipse configuration.
     * 
     * @param aRelativePath
     *            Relative path.
     * @param aTestClass
     *            Test class.
     */
    public static File getPath(String aRelativePath, Class aTestClass) {
        CodeSource source = aTestClass.getProtectionDomain().getCodeSource();
        if (source == null) {
            LOG.warn("Could not obtain path for '" + aRelativePath
                    + "' for class " + aTestClass
                    + ", using relative path as is");
            return new File(aRelativePath);
        }
        URL location = source.getLocation();
        String protocol = location.getProtocol();
        if (!protocol.equals("file")) {
            return new File(aRelativePath);
        }

        String path = location.getPath();
        try {
            path = URLDecoder.decode(location.getPath(), "UTF-8");
        } catch (UnsupportedEncodingException e) {
            // ignore it.. just don't decode
        }

        return new File(new File(path).getParentFile(), aRelativePath);
    }

    /**
     * Ensures that a directory hierarchy exists (recursively if needed). If it
     * is not possible to create the directory, then the test case will fail.
     * 
     * @param aDir
     *            Directory to create.
     */
    public static void createDir(File aDir) {
        if (aDir.exists() && !aDir.isDirectory()) {
            TestCase.fail("'" + aDir
                    + "' already exists and is not a directory");
        }
        if (aDir.exists()) {
            return;
        }
        createDir(aDir.getParentFile());
        TestCase.assertTrue("Could not create '" + aDir + "'", aDir.mkdir());
    }

    /**
     * Gets the test output directory for a specific test class.
     * 
     * @param aTestClass
     *            Test class.
     * @return Test output directory.
     */
    public static File getTestOutputDir(Class aTestClass) {
        File file = getPath(TEST_OUTPUT_DIR, aTestClass);
        String packageName = aTestClass.getPackage().getName();
        String packagePath = packageName.replaceAll("\\.", "/");
        return new File(file, packagePath);
    }

    /**
     * Creates a directory hierarchy for the output directory of a test class if
     * needed.
     * 
     * @param aTestClass
     *            Test class
     * @return Test directory.
     */
    public static File createTestOutputDir(Class aTestClass) {
        File file = getTestOutputDir(aTestClass);
        createDir(file);
        return file;
    }

    /**
     * Gets a test output file name. This returns a File object representing the
     * output file and ensures that the directory where the file will be created
     * already exists.
     * 
     * @param aName
     *            Name of the file.
     * @param aTestClass
     *            Test class.
     * @return File.
     */
    public static File getTestOutputFile(String aName, Class aTestClass) {
        File file = new File(getTestOutputDir(aTestClass), aName);
        createDir(file.getParentFile());
        return file;
    }

    public static String read(InputStream aIs) throws IOException {
        try {
            StringBuffer buffer = new StringBuffer();
            int c;
            while ((c = aIs.read()) != -1) {
                buffer.append((char)c);
            }
            return buffer.toString();
        } finally {
            aIs.close();
        }
    }
}