/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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 weinre.server;

import java.io.File;
import java.io.IOException;
import java.net.MalformedURLException;
import java.util.ArrayList;
import java.util.List;

import org.eclipse.jetty.util.resource.Resource;

//-------------------------------------------------------------------
public class ExtensionManager {
    static private File     weinreHomeDir = null;
    static private File     weinreExtDir  = null;
    static private long     weinreExtDate = 0L;
    static private String[] extensions    = null;

    static private String[] EMPTY_STRING_ARRAY = {};

    //---------------------------------------------------------------
    static {
        initExtensions();
    }

    //---------------------------------------------------------------
    static public String[] getExtensions() {
        if (null == weinreExtDir) return extensions;

        if (weinreExtDate != weinreExtDir.lastModified()) {
            initExtensions();
        }

        return extensions;
    }

    //---------------------------------------------------------------
    // path: /client/extensions/weinre-ext-sample/extension.html
    static public Resource getResource(String path) throws MalformedURLException {
        if (null == weinreExtDir) return null;

        File resourceFile = new File(weinreExtDir, path.substring(18));
        if (!resourceFile.exists()) return null;

        try {
            return Resource.newResource(resourceFile.toURI().toURL().toExternalForm(), false);
        }
        catch (IOException e) {
            throw new MalformedURLException();
        }
    }

    //---------------------------------------------------------------
    static private void initExtensions() {

        extensions = EMPTY_STRING_ARRAY;

        weinreHomeDir = new File(System.getProperty("user.home"), ".weinre");
        if (!weinreHomeDir.isDirectory()) {
            Main.info("extensions not enabled: ~/.weinre is not a directory");
            return;
        }

        weinreExtDir  = new File(weinreHomeDir, "extensions");
        weinreExtDate = weinreExtDir.lastModified();
        if (!weinreExtDir.isDirectory()) {
            Main.info("extensions not enabled: ~/.weinre/extensions is not a directory");
            return;
        }

        List<String> extensionList = new ArrayList<String>();

        String[] entries = weinreExtDir.list();
        for (String entry: entries) {
            if (entry.startsWith(".")) continue;

            File extDir = new File(weinreExtDir, entry);
            if (!extDir.isDirectory()) continue;

            File extensionHtml = new File(extDir, "extension.html");
            if (!extensionHtml.isFile()) continue;

            extensionList.add(entry);
        }

        extensions = extensionList.toArray(EMPTY_STRING_ARRAY);
    }

}