/*
 * Copyright 2002-2005 The Apache Software Foundation.
 * 
 * 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.apache.commons;

import junit.framework.TestCase;
import org.apache.commons.vfs.FileSystemException;
import org.apache.commons.vfs.util.Messages;

import java.io.File;
import java.io.IOException;
import java.lang.reflect.Method;

/**
 * A base class for VFS tests.  Provides utility methods for locating
 * test resources.
 *
 * @author <a href="mailto:adammurdoch@apache.org">Adam Murdoch</a>
 * @version $Revision$ $Date$
 */
public abstract class AbstractVfsTestCase
    extends TestCase
{
    private static File baseDir;

    /**
     * Returns the name of the package containing a class.
     *
     * @return The . delimited package name, or an empty string if the class
     *         is in the default package.
     */
    public static String getPackageName(final Class clazz)
    {
        final Package pkg = clazz.getPackage();
        if (null != pkg)
        {
            return pkg.getName();
        }

        final String name = clazz.getName();
        if (-1 == name.lastIndexOf("."))
        {
            return "";
        }
        else
        {
            return name.substring(0, name.lastIndexOf("."));
        }
    }

    /**
     * Locates a test resource, and asserts that the resource exists
     *
     * @param name path of the resource, relative to this test's base directory.
     */
    public static File getTestResource(final String name)
    {
        return getTestResource(name, true);
    }

    /**
     * Locates a test resource.
     *
     * @param name path of the resource, relative to this test's base directory.
     */
    public static File getTestResource(final String name, final boolean mustExist)
    {
        File file = new File(getTestDirectoryFile(), name);
        file = getCanonicalFile(file);
        if (mustExist)
        {
            assertTrue("Test file \"" + file + "\" does not exist.", file.exists());
        }
        else
        {
            assertTrue("Test file \"" + file + "\" should not exist.", !file.exists());
        }

        return file;
    }

    /**
     * Locates the base directory for this test.
     */
    public static File getTestDirectoryFile()
    {
        if (baseDir == null)
        {
            // final String baseDirProp = System.getProperty("test.basedir");
            final String baseDirProp = getTestDirectory();
            baseDir = getCanonicalFile(new File(baseDirProp));
        }
        return baseDir;
    }

    public static String getTestDirectory()
    {
        return System.getProperty("test.basedir");
        /*
        if (baseDir == null)
        {
            final String baseDirProp = System.getProperty("test.basedir");
            baseDir = getCanonicalFile(new File(baseDirProp));
        }
        return baseDir;
        */
    }

    /**
     * Locates a test directory, creating it if it does not exist.
     *
     * @param name path of the directory, relative to this test's base directory.
     */
    public static File getTestDirectory(final String name)
    {
        File file = new File(getTestDirectoryFile(), name);
        file = getCanonicalFile(file);
        assertTrue("Test directory \"" + file + "\" does not exist or is not a directory.",
            file.isDirectory() || file.mkdirs());
        return file;
    }

    /**
     * Makes a file canonical
     */
    public static File getCanonicalFile(final File file)
    {
        try
        {
            return file.getCanonicalFile();
        }
        catch (IOException e)
        {
            return file.getAbsoluteFile();
        }
    }

    /**
     * Asserts that an exception chain contains the expected messages.
     *
     * @param messages The messages, in order.  A null entry in this array
     *                 indicates that the message should be ignored.
     */
    public static void assertSameMessage(final String[] messages, final Throwable throwable)
    {
        Throwable current = throwable;
        for (int i = 0; i < messages.length; i++)
        {
            String message = messages[i];
            assertNotNull(current);
            if (message != null)
            {
                assertEquals(message, current.getMessage());
            }

            // Get the next exception in the chain
            current = getCause(current);
        }
    }

    /**
     * Returns the cause of an exception.
     */
    public static Throwable getCause(Throwable throwable)
    {
        try
        {
            Method method = throwable.getClass().getMethod("getCause", null);
            return (Throwable) method.invoke(throwable, null);
        }
        catch (Exception e)
        {
            return null;
        }
    }

    /**
     * Asserts that an exception contains the expected message.
     */
    public static void assertSameMessage(final String code,
                                         final Throwable throwable)
    {
        assertSameMessage(code, new Object[0], throwable);
    }

    /**
     * Asserts that an exception contains the expected message.
     */
    public static void assertSameMessage(final String code,
                                         final Object[] params,
                                         final Throwable throwable)
    {
        if (throwable instanceof FileSystemException)
        {
            final FileSystemException fse = (FileSystemException) throwable;

            // Compare message code and params
            assertEquals(code, fse.getCode());
            assertEquals(params.length, fse.getInfo().length);
            for (int i = 0; i < params.length; i++)
            {
                final Object param = params[i];
                assertEquals(String.valueOf(param), fse.getInfo()[i]);
            }
        }

        // Compare formatted message
        final String message = Messages.getString(code, params);
        assertEquals(message, throwable.getMessage());
    }

    /**
     * Asserts that an exception contains the expected message.
     */
    public static void assertSameMessage(final String code,
                                         final Object param,
                                         final Throwable throwable)
    {
        assertSameMessage(code, new Object[]{param}, throwable);
    }

    /**
     * Compares 2 objects for equality, nulls are equal.  Used by the test
     * classes' equals() methods.
     */
    public static boolean equals(final Object o1, final Object o2)
    {
        if (o1 == null && o2 == null)
        {
            return true;
        }
        if (o1 == null || o2 == null)
        {
            return false;
        }
        return o1.equals(o2);
    }
}