/*
 * Copyright (C) 2020 The Android Open Source Project
 *
 * 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.android.server.wifi;

import android.net.IpConfiguration;
import android.net.LinkAddress;
import android.net.ProxyInfo;
import android.net.StaticIpConfiguration;
import android.util.Log;

import java.io.DataOutputStream;
import java.io.IOException;
import java.net.InetAddress;

/**
 * Copied from frameworks/base/services/core/java/com/android/server/net/IpConfigStore.java
 */
public class IpConfigStoreTestWriter {
    private static final String TAG = "IpConfigStoreTestWriter";

    private static final String ID_KEY = "id";
    private static final String IP_ASSIGNMENT_KEY = "ipAssignment";
    private static final String LINK_ADDRESS_KEY = "linkAddress";
    private static final String GATEWAY_KEY = "gateway";
    private static final String DNS_KEY = "dns";
    private static final String PROXY_SETTINGS_KEY = "proxySettings";
    private static final String PROXY_HOST_KEY = "proxyHost";
    private static final String PROXY_PORT_KEY = "proxyPort";
    private static final String PROXY_PAC_FILE = "proxyPac";
    private static final String EXCLUSION_LIST_KEY = "exclusionList";
    private static final String EOS = "eos";

    /** Serialize an IpConfiguration object */
    public static boolean writeConfig(DataOutputStream out, String configKey,
            IpConfiguration config, int version) throws IOException {
        boolean written = false;

        try {
            switch (config.ipAssignment) {
                case STATIC:
                    out.writeUTF(IP_ASSIGNMENT_KEY);
                    out.writeUTF(config.ipAssignment.toString());
                    StaticIpConfiguration staticIpConfiguration = config.staticIpConfiguration;
                    if (staticIpConfiguration != null) {
                        if (staticIpConfiguration.ipAddress != null) {
                            LinkAddress ipAddress = staticIpConfiguration.ipAddress;
                            out.writeUTF(LINK_ADDRESS_KEY);
                            out.writeUTF(ipAddress.getAddress().getHostAddress());
                            out.writeInt(ipAddress.getPrefixLength());
                        }
                        if (staticIpConfiguration.gateway != null) {
                            out.writeUTF(GATEWAY_KEY);
                            out.writeInt(0);  // Default route.
                            out.writeInt(1);  // Have a gateway.
                            out.writeUTF(staticIpConfiguration.gateway.getHostAddress());
                        }
                        for (InetAddress inetAddr : staticIpConfiguration.dnsServers) {
                            out.writeUTF(DNS_KEY);
                            out.writeUTF(inetAddr.getHostAddress());
                        }
                    }
                    written = true;
                    break;
                case DHCP:
                    out.writeUTF(IP_ASSIGNMENT_KEY);
                    out.writeUTF(config.ipAssignment.toString());
                    written = true;
                    break;
                case UNASSIGNED:
                    /* Ignore */
                    break;
                default:
                    loge("Ignore invalid ip assignment while writing");
                    break;
            }

            switch (config.proxySettings) {
                case STATIC:
                    ProxyInfo proxyProperties = config.httpProxy;
                    String exclusionList = proxyProperties.getExclusionListAsString();
                    out.writeUTF(PROXY_SETTINGS_KEY);
                    out.writeUTF(config.proxySettings.toString());
                    out.writeUTF(PROXY_HOST_KEY);
                    out.writeUTF(proxyProperties.getHost());
                    out.writeUTF(PROXY_PORT_KEY);
                    out.writeInt(proxyProperties.getPort());
                    if (exclusionList != null) {
                        out.writeUTF(EXCLUSION_LIST_KEY);
                        out.writeUTF(exclusionList);
                    }
                    written = true;
                    break;
                case PAC:
                    ProxyInfo proxyPacProperties = config.httpProxy;
                    out.writeUTF(PROXY_SETTINGS_KEY);
                    out.writeUTF(config.proxySettings.toString());
                    out.writeUTF(PROXY_PAC_FILE);
                    out.writeUTF(proxyPacProperties.getPacFileUrl().toString());
                    written = true;
                    break;
                case NONE:
                    out.writeUTF(PROXY_SETTINGS_KEY);
                    out.writeUTF(config.proxySettings.toString());
                    written = true;
                    break;
                case UNASSIGNED:
                    /* Ignore */
                    break;
                default:
                    loge("Ignore invalid proxy settings while writing");
                    break;
            }

            if (written) {
                out.writeUTF(ID_KEY);
                if (version < 3) {
                    out.writeInt(Integer.valueOf(configKey));
                } else {
                    out.writeUTF(configKey);
                }
            }
        } catch (NullPointerException e) {
            loge("Failure in writing " + config + e);
        }
        out.writeUTF(EOS);

        return written;
    }

    private static void loge(String s) {
        Log.e(TAG, s);
    }
}