/*
 * (C) Copyright 2006-2011 Nuxeo SA (http://nuxeo.com/) and contributors.
 *
 * 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.
 *
 * Contributors:
 *     Nuxeo - initial API and implementation
 *
 * $Id$
 */

package org.nuxeo.osgi.application;

import java.io.File;
import java.io.IOException;
import java.util.Collection;
import java.util.jar.JarFile;
import java.util.jar.Manifest;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.nuxeo.common.utils.FileNamePattern;
import org.nuxeo.common.utils.JarUtils;
import org.nuxeo.osgi.BundleFile;
import org.nuxeo.osgi.DirectoryBundleFile;
import org.nuxeo.osgi.JarBundleFile;
import org.osgi.framework.BundleException;
import org.osgi.framework.Constants;

/**
 * @author <a href="mailto:bs@nuxeo.com">Bogdan Stefanescu</a>
 */
public class BundleWalker extends FileWalker.Visitor {

    private static final Log log = LogFactory.getLog(BundleWalker.class);

    public static final FileNamePattern[] DEFAULT_PATTERNS = { new FileNamePattern("*.jar"),
            new FileNamePattern("*.war"), new FileNamePattern("*.rar"), new FileNamePattern("*.sar"), // jboss sar
            new FileNamePattern("*_jar"), new FileNamePattern("*_war"), new FileNamePattern("*_rar") };

    private FileNamePattern[] patterns;

    private final Callback callback;

    public BundleWalker(Callback cb) {
        this(cb, DEFAULT_PATTERNS);
    }

    public BundleWalker(Callback cb, String[] patterns) {
        if (patterns != null) {
            this.patterns = new FileNamePattern[patterns.length];
            for (int i = 0; i < patterns.length; i++) {
                this.patterns[i] = new FileNamePattern(patterns[i]);
            }
        }
        callback = cb;
    }

    public BundleWalker(Callback cb, FileNamePattern[] patterns) {
        this.patterns = patterns;
        callback = cb;
    }

    public void visit(File root) {
        new FileWalker().walk(root, this);
    }

    public void visit(Collection<File> files) {
        for (File file : files) {
            if (file.isFile()) {
                if (file.isFile()) {
                    visitFile(file);
                } else if (file.isDirectory()) {
                    visitDirectory(file);
                }
            }
        }
    }

    public void visit(File... files) {
        for (File file : files) {
            if (file.isFile()) {
                if (file.isFile()) {
                    visitFile(file);
                } else if (file.isDirectory()) {
                    visitDirectory(file);
                }
            }
        }
    }

    @Override
    public int visitDirectory(File file) {
        // System.out.println("###### Processing DIR: " + file);
        // first check if this is a possible bundle
        String fileName = file.getName();
        if (patterns != null) {
            if (!acceptFile(fileName, patterns)) {
                return FileWalker.CONTINUE;
            }
        }
        // check if this is an OSGi bundle
        try {
            Manifest mf = JarUtils.getDirectoryManifest(file);
            if (mf == null) {
                return FileWalker.CONTINUE;
            }
            String bundleName = mf.getMainAttributes().getValue(Constants.BUNDLE_SYMBOLICNAME);
            if (bundleName != null) {
                // notify the callback about the new bundle
                callback.visitBundle(new DirectoryBundleFile(file, mf));
                // assume that a directory OSGi bundle cannot contain other bundles so skip it
                return FileWalker.BREAK;
            }
        } catch (IOException e) {
            log.error(e, e);
        }
        return FileWalker.CONTINUE;
    }

    @Override
    public int visitFile(File file) {
        // System.out.println("###### Processing file: "+file);
        // first check if this is a possible bundle
        String fileName = file.getName();
        if (patterns != null) {
            if (!acceptFile(fileName, patterns)) {
                // System.out.println("###### Ignoring file based on name: "+file);
                return FileWalker.CONTINUE;
            }
        }
        // check if this is an OSGi bundle
        try {
            JarFile jarFile = new JarFile(file);
            if (jarFile.getManifest() == null) {
                // System.out.println("###### No manifest found: "+file);
                return FileWalker.CONTINUE;
            }
            BundleFile bundleFile = new JarBundleFile(jarFile);
            if (bundleFile.getSymbolicName() != null) {
                // System.out.println("###### Bundle symbolic name: "+bundleFile.getSymbolicName());

                // notify the callback about the new bundle
                callback.visitBundle(bundleFile);
            } else {
                // notify the callback about the new jar
                callback.visitJar(bundleFile);
            }
        } catch (IOException e) {
            // ignore
        }
        return FileWalker.CONTINUE;
    }

    protected boolean acceptFile(String fileName, FileNamePattern[] patterns) {
        int i = 0;
        for (; i < patterns.length; i++) {
            if (patterns[i].match(fileName)) {
                break;
            }
        }
        return i < patterns.length;
    }

    public interface Callback {
        void visitBundle(BundleFile bundleFile) throws IOException;

        void visitJar(BundleFile bundleFile) throws IOException;
    }

}