/*
 * Copyright (c) 2012-2016 Arne Schwabe
 * Distributed under the GNU GPL v2 with additional terms. For full terms see the file doc/LICENSE.txt
 */
package de.blinkt.openvpn.core;

import java.net.InetSocketAddress;
import java.net.MalformedURLException;
import java.net.Proxy;
import java.net.ProxySelector;
import java.net.SocketAddress;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.List;

import com.reactlibrary.R;
import de.blinkt.openvpn.VpnProfile;

public class ProxyDetection {
    static SocketAddress detectProxy(VpnProfile vp) {
        // Construct a new url with https as protocol
        try {
            URL url = new URL(String.format("https://%s:%s", vp.mServerName, vp.mServerPort));
            Proxy proxy = getFirstProxy(url);
            if (proxy == null) return null;
            SocketAddress addr = proxy.address();
            if (addr instanceof InetSocketAddress) {
                return addr;
            }
        } catch (MalformedURLException e) {
            VpnStatus.logError(R.string.getproxy_error, e.getLocalizedMessage());
        } catch (URISyntaxException e) {
            VpnStatus.logError(R.string.getproxy_error, e.getLocalizedMessage());
        }
        return null;
    }

    static Proxy getFirstProxy(URL url) throws URISyntaxException {
        System.setProperty("java.net.useSystemProxies", "true");
        List<Proxy> proxylist = ProxySelector.getDefault().select(url.toURI());
        if (proxylist != null) {
            for (Proxy proxy : proxylist) {
                SocketAddress addr = proxy.address();
                if (addr != null) {
                    return proxy;
                }
            }
        }
        return null;
    }
}