/*******************************************************************************
 *
 * Copyright (c) 2004-2009 Oracle Corporation.
 *
 * 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:
 * 
 *    Kohsuke Kawaguchi
 *
 *
 *******************************************************************************/ 

package org.jvnet.hudson.test;

import hudson.FilePath;
import org.apache.commons.io.FileUtils;

import java.io.File;
import java.io.IOException;
import java.lang.reflect.Method;
import java.net.MalformedURLException;
import java.net.URL;

/**
 * Controls how a {@link HudsonTestCase} initializes <tt>HUDSON_HOME</tt>.
 *
 * @author Kohsuke Kawaguchi
 */
public interface HudsonHomeLoader {

    /**
     * Returns a directory to be used as <tt>HUDSON_HOME</tt>
     *
     * @throws Exception to cause a test to fail.
     */
    File allocate() throws Exception;
    /**
     * Allocates a new empty directory, meaning this will emulate the fresh
     * Hudson installation.
     */
    public static final HudsonHomeLoader NEW = new HudsonHomeLoader() {
        public File allocate() throws IOException {
            return TestEnvironment.get().temporaryDirectoryAllocator.allocate();
        }
    };

    /**
     * Allocates a new directory by copying from an existing directory, or
     * unzipping from a zip file.
     */
    public static final class CopyExisting implements HudsonHomeLoader {

        private final URL source;

        /**
         * Either a zip file or a directory that contains the home image.
         */
        public CopyExisting(File source) throws MalformedURLException {
            this(source.toURI().toURL());
        }

        /**
         * Extracts from a zip file in the resource.
         *
         * <p> This is useful in case you want to have a test data in the
         * resources. Only file URL is supported.
         */
        public CopyExisting(URL source) {
            this.source = source;
        }

        public File allocate() throws Exception {
            File target = NEW.allocate();
            if (source.getProtocol().equals("file")) {
                File src = new File(source.toURI());
                if (src.isDirectory()) {
                    new FilePath(src).copyRecursiveTo("**/*", new FilePath(target));
                } else if (src.getName().endsWith(".zip")) {
                    new FilePath(src).unzip(new FilePath(target));
                }
            } else {
                File tmp = File.createTempFile("hudson", "zip");
                try {
                    FileUtils.copyURLToFile(source, tmp);
                    new FilePath(tmp).unzip(new FilePath(target));
                } finally {
                    tmp.delete();
                }
            }
            return target;
        }
    }

    /**
     * Allocates a new directory by copying from a test resource
     */
    public static final class Local implements HudsonHomeLoader {

        private final Method testMethod;

        public Local(Method testMethod) {
            this.testMethod = testMethod;
        }

        public File allocate() throws Exception {
            URL res = findDataResource();
            if (!res.getProtocol().equals("file")) {
                throw new AssertionError("Test data is not available in the file system: " + res);
            }
            // if we picked up a directory, it's one level above config.xml
            File home = new File(res.toURI());
            if (!home.getName().endsWith(".zip")) {
                home = home.getParentFile();
            }

            return new CopyExisting(home).allocate();
        }

        private URL findDataResource() {
            // first, check method specific resource
            Class<?> clazz = testMethod.getDeclaringClass();

            for (String middle : new String[]{'/' + testMethod.getName(), ""}) {
                for (String suffix : SUFFIXES) {
                    URL res = clazz.getResource(clazz.getSimpleName() + middle + suffix);
                    if (res != null) {
                        return res;
                    }
                }
            }

            throw new AssertionError("No test resource was found for " + testMethod);
        }
        private static final String[] SUFFIXES = {"/config.xml", ".zip"};
    }
}