/*
 * Copyright (C) 2010-2015, Martin Goellnitz
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA, 02110-1301, USA
 */
package jfs.sync.util;

import java.io.IOException;
import java.net.Proxy;
import java.net.ProxySelector;
import java.net.SocketAddress;
import java.net.URI;
import java.util.List;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;


/**
 * Utility class to automatically detect windows http proxy settings.
 */
public final class WindowsProxySelector extends ProxySelector {

    private static final Logger LOG = LoggerFactory.getLogger(WindowsProxySelector.class);

    private final ProxySelector root;


    /**
     * Stores the only instance of the class.
     *
     * SingletonHolder is loaded on the first execution of JFSTable.getInstance()
     * or the first access to SingletonHolder.INSTANCE, not before.
     */
    private static class SingletonHolder {

        public static final ProxySelector INSTANCE = new WindowsProxySelector();

    }


    protected WindowsProxySelector() {
        root = ProxySelector.getDefault();
        ProxySelector.setDefault(null);
        LOG.debug("select() root {}", root);
    } // WindowsProxySelector()


    public static ProxySelector getInstance() {
        return SingletonHolder.INSTANCE;
    } // getInstance()


    @Override
    public List<Proxy> select(URI uri) {
        URI url = URI.create(uri.toString().replace("https://", "http://"));
        List<Proxy> result = root.select(url);
        LOG.debug("select() uri {}", uri);
        LOG.debug("select() url {}", url);
        LOG.debug("select() proxies {}", result);
        return result;
    }// select()


    @Override
    public void connectFailed(URI uri, SocketAddress sa, IOException ioe) {
        root.connectFailed(uri, sa, ioe);
    } // connectFailed()

} // WindowsProxySelector()