/*
 * Copyright (C) 2019 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 android.net.ipsec.test.ike;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;
import static org.mockito.Mockito.mock;

import android.net.InetAddresses;
import android.net.IpPrefix;
import android.net.LinkAddress;

import com.android.internal.net.ipsec.test.ike.message.IkeConfigPayload;
import com.android.internal.net.ipsec.test.ike.message.IkeConfigPayload.ConfigAttribute;
import com.android.internal.net.ipsec.test.ike.message.IkeConfigPayload.ConfigAttributeIpv4Address;
import com.android.internal.net.ipsec.test.ike.message.IkeConfigPayload.ConfigAttributeIpv4Dhcp;
import com.android.internal.net.ipsec.test.ike.message.IkeConfigPayload.ConfigAttributeIpv4Dns;
import com.android.internal.net.ipsec.test.ike.message.IkeConfigPayload.ConfigAttributeIpv4Netmask;
import com.android.internal.net.ipsec.test.ike.message.IkeConfigPayload.ConfigAttributeIpv4Pcscf;
import com.android.internal.net.ipsec.test.ike.message.IkeConfigPayload.ConfigAttributeIpv4Subnet;
import com.android.internal.net.ipsec.test.ike.message.IkeConfigPayload.ConfigAttributeIpv6Address;
import com.android.internal.net.ipsec.test.ike.message.IkeConfigPayload.ConfigAttributeIpv6Dns;
import com.android.internal.net.ipsec.test.ike.message.IkeConfigPayload.ConfigAttributeIpv6Subnet;

import org.junit.Before;
import org.junit.Test;

import java.net.Inet4Address;
import java.net.Inet6Address;
import java.net.InetAddress;
import java.util.ArrayList;
import java.util.List;

public final class ChildSessionConfigurationTest {
    private static final int IP4_PREFIX_LEN = 28;
    private static final Inet4Address IPV4_ADDRESS =
            (Inet4Address) InetAddresses.parseNumericAddress("192.0.2.100");
    private static final Inet4Address IPV4_NETMASK =
            (Inet4Address) InetAddresses.parseNumericAddress("255.255.255.240");
    private static final LinkAddress IPV4_LINK_ADDRESS =
            new LinkAddress(IPV4_ADDRESS, IP4_PREFIX_LEN);
    private static final IpPrefix IPV4_SUBNET_IP_PREFIX_ADDRESS = new IpPrefix("198.51.100.0/24");
    private static final IpPrefix IPV6_SUBNET_IP_PREFIX_ADDRESS =
            new IpPrefix("2001:db8:abcd:0012::0/64");

    private static final int IP6_PREFIX_LEN = 64;
    private static final Inet6Address IPV6_ADDRESS =
            (Inet6Address) InetAddresses.parseNumericAddress("2001:db8::1");
    private static final LinkAddress IPV6_LINK_ADDRESS =
            new LinkAddress(IPV6_ADDRESS, IP6_PREFIX_LEN);

    private List mMockInTsList;
    private List mMockOutTsList;

    private ConfigAttributeIpv4Address mIpv4Attr;
    private ConfigAttributeIpv4Netmask mNetmaskAttr;
    private ConfigAttributeIpv6Address mIpv6Attr;
    private ConfigAttributeIpv4Dns mIpv4Dns;
    private ConfigAttributeIpv6Dns mIpv6Dns;
    private ConfigAttributeIpv4Subnet mIpv4Subnet;
    private ConfigAttributeIpv6Subnet mIpv6Subnet;
    private ConfigAttributeIpv4Dhcp mIpv4Dhcp;
    private ConfigAttributeIpv4Pcscf mIpv4Pcscf;

    @Before
    public void setUp() throws Exception {
        mMockInTsList = new ArrayList<IkeTrafficSelector>();
        mMockInTsList.add(mock(IkeTrafficSelector.class));

        mMockOutTsList = new ArrayList<IkeTrafficSelector>();
        mMockOutTsList.add(mock(IkeTrafficSelector.class));
        mMockOutTsList.add(mock(IkeTrafficSelector.class));

        mIpv4Attr = new ConfigAttributeIpv4Address(IPV4_ADDRESS);
        mNetmaskAttr = new ConfigAttributeIpv4Netmask(IPV4_NETMASK.getAddress());
        mIpv6Attr = new ConfigAttributeIpv6Address(IPV6_LINK_ADDRESS);
        mIpv4Dns = new ConfigAttributeIpv4Dns(IPV4_ADDRESS);
        mIpv6Dns = new ConfigAttributeIpv6Dns(IPV6_ADDRESS);
        mIpv4Dhcp = new ConfigAttributeIpv4Dhcp(IPV4_ADDRESS);
        mIpv4Subnet =
                new ConfigAttributeIpv4Subnet(
                        new LinkAddress(IPV4_SUBNET_IP_PREFIX_ADDRESS.toString()));
        mIpv6Subnet =
                new ConfigAttributeIpv6Subnet(
                        new LinkAddress(IPV6_SUBNET_IP_PREFIX_ADDRESS.toString()));
        mIpv4Pcscf = new ConfigAttributeIpv4Pcscf(IPV4_ADDRESS);
    }

    private void verifySessionConfigCommon(ChildSessionConfiguration sessionConfig) {
        verifyTsList(mMockInTsList, sessionConfig.getInboundTrafficSelectors());
        verifyTsList(mMockOutTsList, sessionConfig.getOutboundTrafficSelectors());
    }

    private void verifyTsList(
            List<IkeTrafficSelector> expectedList, List<IkeTrafficSelector> tsList) {
        assertEquals(expectedList.size(), tsList.size());
        for (int i = 0; i < expectedList.size(); i++) {
            assertEquals(expectedList.get(i), tsList.get(i));
        }
    }

    @Test
    public void testBuildWithoutConfig() {
        ChildSessionConfiguration sessionConfig =
                new ChildSessionConfiguration(mMockInTsList, mMockOutTsList);

        verifySessionConfigCommon(sessionConfig);
    }

    @Test
    public void testBuildWithNetmaskAttr() {
        List<ConfigAttribute> attributeList = new ArrayList<>();
        attributeList.add(mIpv4Attr);
        attributeList.add(mNetmaskAttr);
        attributeList.add(mIpv6Attr);

        IkeConfigPayload configPayload = new IkeConfigPayload(true /*isReply*/, attributeList);

        ChildSessionConfiguration sessionConfig =
                new ChildSessionConfiguration(mMockInTsList, mMockOutTsList, configPayload);

        verifySessionConfigCommon(sessionConfig);
        validateInternalAddrList(sessionConfig);
    }

    private void validateInternalAddrList(ChildSessionConfiguration sessionConfig) {
        List<LinkAddress> expectedInternalAddrList = new ArrayList<>();
        expectedInternalAddrList.add(IPV4_LINK_ADDRESS);
        expectedInternalAddrList.add(IPV6_LINK_ADDRESS);

        assertEquals(expectedInternalAddrList.size(), sessionConfig.getInternalAddresses().size());
        for (int i = 0; i < expectedInternalAddrList.size(); i++) {
            assertEquals(
                    expectedInternalAddrList.get(i), sessionConfig.getInternalAddresses().get(i));
        }
    }

    @Test
    public void testBuildWithoutNetmaskAttr() {
        List<ConfigAttribute> attributeList = new ArrayList<>();
        attributeList.add(mIpv4Attr);
        attributeList.add(mIpv6Attr);

        IkeConfigPayload configPayload = new IkeConfigPayload(true /*isReply*/, attributeList);

        ChildSessionConfiguration sessionConfig =
                new ChildSessionConfiguration(mMockInTsList, mMockOutTsList, configPayload);

        verifySessionConfigCommon(sessionConfig);

        List<LinkAddress> expectedInternalAddrList = new ArrayList<>();
        expectedInternalAddrList.add(new LinkAddress(IPV4_ADDRESS, 32));
        expectedInternalAddrList.add(IPV6_LINK_ADDRESS);

        assertEquals(expectedInternalAddrList.size(), sessionConfig.getInternalAddresses().size());
        for (int i = 0; i < expectedInternalAddrList.size(); i++) {
            assertEquals(
                    expectedInternalAddrList.get(i), sessionConfig.getInternalAddresses().get(i));
        }
    }

    @Test
    public void testBuildWithConfigReq() {
        List<ConfigAttribute> attributeList = new ArrayList<>();
        attributeList.add(mIpv4Attr);
        attributeList.add(mIpv6Attr);

        IkeConfigPayload configPayload = new IkeConfigPayload(false /*isReply*/, attributeList);

        try {
            new ChildSessionConfiguration(mMockInTsList, mMockOutTsList, configPayload);
            fail("Expected to fail because provided config paylaod is not a reply.");
        } catch (IllegalArgumentException expected) {

        }
    }

    @Test
    public void testBuildWithDnsAttr() {
        List<ConfigAttribute> attributeList = new ArrayList<>();
        attributeList.add(mIpv4Dns);
        attributeList.add(mIpv6Dns);
        attributeList.add(mIpv4Pcscf);

        IkeConfigPayload configPayload = new IkeConfigPayload(true /*isReply*/, attributeList);

        ChildSessionConfiguration sessionConfig =
                new ChildSessionConfiguration(mMockInTsList, mMockOutTsList, configPayload);

        verifySessionConfigCommon(sessionConfig);
        validateDnsAddrList(sessionConfig);
    }

    private void validateDnsAddrList(ChildSessionConfiguration sessionConfig) {
        List<InetAddress> expectedDnsAddrList = new ArrayList<>();
        expectedDnsAddrList.add(IPV4_ADDRESS);
        expectedDnsAddrList.add(IPV6_ADDRESS);

        assertEquals(expectedDnsAddrList.size(), sessionConfig.getInternalDnsServers().size());
        for (int i = 0; i < expectedDnsAddrList.size(); i++) {
            assertEquals(expectedDnsAddrList.get(i), sessionConfig.getInternalDnsServers().get(i));
        }
    }

    @Test
    public void testBuildWithSubnetAttr() {
        List<ConfigAttribute> attributeList = new ArrayList<>();
        attributeList.add(mIpv4Subnet);
        attributeList.add(mIpv6Subnet);

        IkeConfigPayload configPayload = new IkeConfigPayload(true /*isReply*/, attributeList);

        ChildSessionConfiguration sessionConfig =
                new ChildSessionConfiguration(mMockInTsList, mMockOutTsList, configPayload);

        verifySessionConfigCommon(sessionConfig);
        validateSubnetAddrList(sessionConfig);
    }

    private void validateSubnetAddrList(ChildSessionConfiguration sessionConfig) {
        List<IpPrefix> expectedSubnetAddrList = new ArrayList<>();
        expectedSubnetAddrList.add(IPV4_SUBNET_IP_PREFIX_ADDRESS);
        expectedSubnetAddrList.add(IPV6_SUBNET_IP_PREFIX_ADDRESS);

        assertEquals(expectedSubnetAddrList.size(), sessionConfig.getInternalSubnets().size());
        for (int i = 0; i < expectedSubnetAddrList.size(); i++) {
            assertEquals(expectedSubnetAddrList.get(i), sessionConfig.getInternalSubnets().get(i));
        }
    }

    @Test
    public void testBuildWithDhcpAttr() {
        List<ConfigAttribute> attributeList = new ArrayList<>();
        attributeList.add(mIpv4Dhcp);

        IkeConfigPayload configPayload = new IkeConfigPayload(true /*isReply*/, attributeList);

        ChildSessionConfiguration sessionConfig =
                new ChildSessionConfiguration(mMockInTsList, mMockOutTsList, configPayload);

        verifySessionConfigCommon(sessionConfig);
        validateDhcpServers(sessionConfig);
    }

    private void validateDhcpServers(ChildSessionConfiguration sessionConfig) {
        assertEquals(1, sessionConfig.getInternalDhcpServers().size());
        assertEquals(sessionConfig.getInternalDhcpServers().get(0), IPV4_ADDRESS);
    }

    @Test
    public void testBuildChildSessionConfigurationWithBuilder() {
        ChildSessionConfiguration sessionConfig =
                new ChildSessionConfiguration.Builder(mMockInTsList, mMockOutTsList)
                        .addInternalAddress(IPV4_LINK_ADDRESS)
                        .addInternalAddress(IPV6_LINK_ADDRESS)
                        .addInternalSubnet(IPV4_SUBNET_IP_PREFIX_ADDRESS)
                        .addInternalSubnet(IPV6_SUBNET_IP_PREFIX_ADDRESS)
                        .addInternalDnsServer(IPV4_ADDRESS)
                        .addInternalDnsServer(IPV6_ADDRESS)
                        .addInternalDhcpServer(IPV4_ADDRESS)
                        .build();

        verifySessionConfigCommon(sessionConfig);
        validateInternalAddrList(sessionConfig);
        validateSubnetAddrList(sessionConfig);
        validateDnsAddrList(sessionConfig);
        validateDhcpServers(sessionConfig);
    }
}