/*
 * Copyright 2019 Hippo Seven
 *
 * 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.
 */

package com.hippo.ehviewer;

import android.text.TextUtils;

import com.hippo.network.InetValidator;
import com.hippo.util.ExceptionUtils;

import java.io.IOException;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Proxy;
import java.net.ProxySelector;
import java.net.SocketAddress;
import java.net.URI;
import java.util.Collections;
import java.util.List;

public class EhProxySelector extends ProxySelector {

    public static final int TYPE_DIRECT = 0;
    public static final int TYPE_SYSTEM = 1;
    public static final int TYPE_HTTP = 2;
    public static final int TYPE_SOCKS = 3;

    private ProxySelector delegation;
    private ProxySelector alternative;

    EhProxySelector() {
        alternative = ProxySelector.getDefault();
        if (alternative == null) {
            alternative = new NullProxySelector();
        }

        updateProxy();
    }

    public void updateProxy() {
        switch (Settings.getProxyType()) {
            case TYPE_DIRECT:
                delegation = new NullProxySelector();
                break;
            default:
            case TYPE_SYSTEM:
                delegation = alternative;
                break;
            case TYPE_HTTP:
            case TYPE_SOCKS:
                delegation = null;
                break;
        }
    }

    @Override
    public List<Proxy> select(URI uri) {
        int type = Settings.getProxyType();
        if (type == TYPE_HTTP || type == TYPE_SOCKS) {
            try {
                String ip = Settings.getProxyIp();
                int port = Settings.getProxyPort();
                if (!TextUtils.isEmpty(ip) && InetValidator.isValidInetPort(port)) {
                    InetAddress inetAddress = InetAddress.getByName(ip);
                    SocketAddress socketAddress = new InetSocketAddress(inetAddress, port);
                    return Collections.singletonList(new Proxy(type == TYPE_HTTP ? Proxy.Type.HTTP : Proxy.Type.SOCKS, socketAddress));
                }
            } catch (Throwable t) {
                ExceptionUtils.throwIfFatal(t);
            }
        }

        if (delegation != null) {
            return delegation.select(uri);
        }

        return alternative.select(uri);
    }

    @Override
    public void connectFailed(URI uri, SocketAddress sa, IOException ioe) {
        if (delegation != null) {
            delegation.select(uri);
        }
    }

    private static class NullProxySelector extends ProxySelector {
        @Override
        public List<Proxy> select(URI uri) {
            return Collections.singletonList(Proxy.NO_PROXY);
        }

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