/*
 * 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 android.system.OsConstants.AF_INET;

import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.fail;

import android.net.InetAddresses;
import android.os.PersistableBundle;

import org.junit.Test;

import java.net.InetAddress;
import java.util.Arrays;

public final class ChildSessionParamsTest {
    private static final int NUM_TS = 2;

    private final ChildSaProposal mSaProposal;
    private final IkeTrafficSelector mTsInbound;
    private final IkeTrafficSelector mTsOutbound;

    public ChildSessionParamsTest() {
        mSaProposal =
                new ChildSaProposal.Builder()
                        .addEncryptionAlgorithm(
                                SaProposal.ENCRYPTION_ALGORITHM_AES_GCM_12,
                                SaProposal.KEY_LEN_AES_128)
                        .build();
        mTsInbound =
                new IkeTrafficSelector(
                        16,
                        65520,
                        InetAddress.parseNumericAddress("192.0.2.100"),
                        InetAddress.parseNumericAddress("192.0.2.101"));
        mTsOutbound =
                new IkeTrafficSelector(
                        32,
                        256,
                        InetAddress.parseNumericAddress("192.0.2.200"),
                        InetAddress.parseNumericAddress("192.0.2.255"));
    }

    @Test
    public void testBuild() throws Exception {
        ChildSessionParams sessionParams =
                new TunnelModeChildSessionParams.Builder().addSaProposal(mSaProposal).build();

        assertArrayEquals(new SaProposal[] {mSaProposal}, sessionParams.getSaProposalsInternal());
        assertArrayEquals(
                new IkeTrafficSelector[] {getExpectedDefaultIpv4Ts(), getExpectedDefaultIpv6Ts()},
                sessionParams.getInboundTrafficSelectorsInternal());
        assertArrayEquals(
                new IkeTrafficSelector[] {getExpectedDefaultIpv4Ts(), getExpectedDefaultIpv6Ts()},
                sessionParams.getOutboundTrafficSelectorsInternal());
        assertFalse(sessionParams.isTransportMode());
    }

    @Test
    public void testInternalGetterReturnsDifferentInstances() throws Exception {
        ChildSessionParams sessionParams =
                new TunnelModeChildSessionParams.Builder().addSaProposal(mSaProposal).build();

        sessionParams.getSaProposalsInternal()[0] = null;
        assertNotNull(sessionParams.getSaProposalsInternal()[0]);
        sessionParams.getInboundTrafficSelectorsInternal()[0] = null;
        assertNotNull(sessionParams.getInboundTrafficSelectorsInternal()[0]);
        sessionParams.getOutboundTrafficSelectorsInternal()[0] = null;
        assertNotNull(sessionParams.getOutboundTrafficSelectorsInternal()[0]);
    }

    private static void verifyPersistableBundleEncodeDecodeIsLossless(ChildSessionParams params) {
        PersistableBundle bundle = params.toPersistableBundle();
        ChildSessionParams result = ChildSessionParams.fromPersistableBundle(bundle);

        assertEquals(params, result);
    }

    @Test
    public void testPersistableBundleEncodeDecodeIsLosslessTunnelMode() throws Exception {
        ChildSessionParams sessionParams =
                new TunnelModeChildSessionParams.Builder()
                        .addSaProposal(mSaProposal)
                        .addInternalAddressRequest(AF_INET)
                        .build();
        verifyPersistableBundleEncodeDecodeIsLossless(sessionParams);
    }

    @Test
    public void testPersistableBundleEncodeDecodeIsLosslessTransportMode() throws Exception {
        ChildSessionParams sessionParams =
                new TransportModeChildSessionParams.Builder().addSaProposal(mSaProposal).build();
        verifyPersistableBundleEncodeDecodeIsLossless(sessionParams);
    }

    @Test
    public void testBuildTrafficSelectors() {
        ChildSessionParams sessionParams =
                new TunnelModeChildSessionParams.Builder()
                        .addSaProposal(mSaProposal)
                        .addInboundTrafficSelectors(mTsInbound)
                        .addOutboundTrafficSelectors(mTsOutbound)
                        .build();

        assertEquals(Arrays.asList(mSaProposal), sessionParams.getSaProposals());
        assertEquals(Arrays.asList(mTsInbound), sessionParams.getInboundTrafficSelectors());
        assertEquals(Arrays.asList(mTsOutbound), sessionParams.getOutboundTrafficSelectors());
    }

    @Test
    public void testBuildWithoutSaProposal() throws Exception {
        try {
            new TunnelModeChildSessionParams.Builder().build();
            fail("Expected to fail due to the absence of SA proposal.");
        } catch (IllegalArgumentException expected) {
        }
    }

    private IkeTrafficSelector getExpectedDefaultIpv4Ts() {
        final InetAddress tsStartAddress = InetAddresses.parseNumericAddress("0.0.0.0");
        final InetAddress tsEndAddress = InetAddresses.parseNumericAddress("255.255.255.255");

        return new IkeTrafficSelector(0, 65535, tsStartAddress, tsEndAddress);
    }

    private IkeTrafficSelector getExpectedDefaultIpv6Ts() {
        final InetAddress tsStartAddress = InetAddresses.parseNumericAddress("::");
        final InetAddress tsEndAddress = InetAddresses.parseNumericAddress(
                "ffff:ffff:ffff:ffff:ffff:ffff:ffff:ffff");

        return new IkeTrafficSelector(0, 65535, tsStartAddress, tsEndAddress);
    }

    @Test
    public void testConstructTransportModeChildParamsCopy() throws Exception {
        TransportModeChildSessionParams childParams =
                new TransportModeChildSessionParams.Builder()
                        .addInboundTrafficSelectors(mTsInbound)
                        .addOutboundTrafficSelectors(mTsOutbound)
                        .addSaProposal(mSaProposal)
                        .build();

        TransportModeChildSessionParams result =
                new TransportModeChildSessionParams.Builder(childParams).build();
        assertEquals(childParams, result);
    }
}