/*
 * Copyright (C) 2014 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;

import android.net.IpPrefix;
import android.os.Parcel;
import static android.test.MoreAsserts.assertNotEqual;
import android.test.suitebuilder.annotation.SmallTest;

import static org.junit.Assert.assertArrayEquals;
import java.net.InetAddress;
import java.util.Random;
import junit.framework.TestCase;


public class IpPrefixTest extends TestCase {

    // Explicitly cast everything to byte because "error: possible loss of precision".
    private static final byte[] IPV4_BYTES = { (byte) 192, (byte) 0, (byte) 2, (byte) 4};
    private static final byte[] IPV6_BYTES = {
        (byte) 0x20, (byte) 0x01, (byte) 0x0d, (byte) 0xb8,
        (byte) 0xde, (byte) 0xad, (byte) 0xbe, (byte) 0xef,
        (byte) 0x0f, (byte) 0x00, (byte) 0x00, (byte) 0x00,
        (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0xa0
    };

    @SmallTest
    public void testConstructor() {
        IpPrefix p;
        try {
            p = new IpPrefix((byte[]) null, 9);
            fail("Expected NullPointerException: null byte array");
        } catch(RuntimeException expected) {}

        try {
            p = new IpPrefix((InetAddress) null, 10);
            fail("Expected NullPointerException: null InetAddress");
        } catch(RuntimeException expected) {}

        try {
            p = new IpPrefix((String) null);
            fail("Expected NullPointerException: null String");
        } catch(RuntimeException expected) {}


        try {
            byte[] b2 = {1, 2, 3, 4, 5};
            p = new IpPrefix(b2, 29);
            fail("Expected IllegalArgumentException: invalid array length");
        } catch(IllegalArgumentException expected) {}

        try {
            p = new IpPrefix("1.2.3.4");
            fail("Expected IllegalArgumentException: no prefix length");
        } catch(IllegalArgumentException expected) {}

        try {
            p = new IpPrefix("1.2.3.4/");
            fail("Expected IllegalArgumentException: empty prefix length");
        } catch(IllegalArgumentException expected) {}

        try {
            p = new IpPrefix("foo/32");
            fail("Expected IllegalArgumentException: invalid address");
        } catch(IllegalArgumentException expected) {}

        try {
            p = new IpPrefix("1/32");
            fail("Expected IllegalArgumentException: deprecated IPv4 format");
        } catch(IllegalArgumentException expected) {}

        try {
            p = new IpPrefix("1.2.3.256/32");
            fail("Expected IllegalArgumentException: invalid IPv4 address");
        } catch(IllegalArgumentException expected) {}

        try {
            p = new IpPrefix("foo/32");
            fail("Expected IllegalArgumentException: non-address");
        } catch(IllegalArgumentException expected) {}

        try {
            p = new IpPrefix("f00:::/32");
            fail("Expected IllegalArgumentException: invalid IPv6 address");
        } catch(IllegalArgumentException expected) {}
    }

    public void testTruncation() {
        IpPrefix p;

        p = new IpPrefix(IPV4_BYTES, 32);
        assertEquals("192.0.2.4/32", p.toString());

        p = new IpPrefix(IPV4_BYTES, 29);
        assertEquals("192.0.2.0/29", p.toString());

        p = new IpPrefix(IPV4_BYTES, 8);
        assertEquals("192.0.0.0/8", p.toString());

        p = new IpPrefix(IPV4_BYTES, 0);
        assertEquals("0.0.0.0/0", p.toString());

        try {
            p = new IpPrefix(IPV4_BYTES, 33);
            fail("Expected IllegalArgumentException: invalid prefix length");
        } catch(RuntimeException expected) {}

        try {
            p = new IpPrefix(IPV4_BYTES, 128);
            fail("Expected IllegalArgumentException: invalid prefix length");
        } catch(RuntimeException expected) {}

        try {
            p = new IpPrefix(IPV4_BYTES, -1);
            fail("Expected IllegalArgumentException: negative prefix length");
        } catch(RuntimeException expected) {}

        p = new IpPrefix(IPV6_BYTES, 128);
        assertEquals("2001:db8:dead:beef:f00::a0/128", p.toString());

        p = new IpPrefix(IPV6_BYTES, 122);
        assertEquals("2001:db8:dead:beef:f00::80/122", p.toString());

        p = new IpPrefix(IPV6_BYTES, 64);
        assertEquals("2001:db8:dead:beef::/64", p.toString());

        p = new IpPrefix(IPV6_BYTES, 3);
        assertEquals("2000::/3", p.toString());

        p = new IpPrefix(IPV6_BYTES, 0);
        assertEquals("::/0", p.toString());

        try {
            p = new IpPrefix(IPV6_BYTES, -1);
            fail("Expected IllegalArgumentException: negative prefix length");
        } catch(RuntimeException expected) {}

        try {
            p = new IpPrefix(IPV6_BYTES, 129);
            fail("Expected IllegalArgumentException: negative prefix length");
        } catch(RuntimeException expected) {}

    }

    private void assertAreEqual(Object o1, Object o2) {
        assertTrue(o1.equals(o2));
        assertTrue(o2.equals(o1));
    }

    private void assertAreNotEqual(Object o1, Object o2) {
        assertFalse(o1.equals(o2));
        assertFalse(o2.equals(o1));
    }

    @SmallTest
    public void testEquals() {
        IpPrefix p1, p2;

        p1 = new IpPrefix("192.0.2.251/23");
        p2 = new IpPrefix(new byte[]{(byte) 192, (byte) 0, (byte) 2, (byte) 251}, 23);
        assertAreEqual(p1, p2);

        p1 = new IpPrefix("192.0.2.5/23");
        assertAreEqual(p1, p2);

        p1 = new IpPrefix("192.0.2.5/24");
        assertAreNotEqual(p1, p2);

        p1 = new IpPrefix("192.0.4.5/23");
        assertAreNotEqual(p1, p2);


        p1 = new IpPrefix("2001:db8:dead:beef:f00::80/122");
        p2 = new IpPrefix(IPV6_BYTES, 122);
        assertEquals("2001:db8:dead:beef:f00::80/122", p2.toString());
        assertAreEqual(p1, p2);

        p1 = new IpPrefix("2001:db8:dead:beef:f00::bf/122");
        assertAreEqual(p1, p2);

        p1 = new IpPrefix("2001:db8:dead:beef:f00::8:0/123");
        assertAreNotEqual(p1, p2);

        p1 = new IpPrefix("2001:db8:dead:beef::/122");
        assertAreNotEqual(p1, p2);

        // 192.0.2.4/32 != c000:0204::/32.
        byte[] ipv6bytes = new byte[16];
        System.arraycopy(IPV4_BYTES, 0, ipv6bytes, 0, IPV4_BYTES.length);
        p1 = new IpPrefix(ipv6bytes, 32);
        assertAreEqual(p1, new IpPrefix("c000:0204::/32"));

        p2 = new IpPrefix(IPV4_BYTES, 32);
        assertAreNotEqual(p1, p2);
    }

    @SmallTest
    public void testHashCode() {
        IpPrefix p;
        int oldCode = -1;
        Random random = new Random();
        for (int i = 0; i < 100; i++) {
            if (random.nextBoolean()) {
                // IPv4.
                byte[] b = new byte[4];
                random.nextBytes(b);
                p = new IpPrefix(b, random.nextInt(33));
                assertNotEqual(oldCode, p.hashCode());
                oldCode = p.hashCode();
            } else {
                // IPv6.
                byte[] b = new byte[16];
                random.nextBytes(b);
                p = new IpPrefix(b, random.nextInt(129));
                assertNotEqual(oldCode, p.hashCode());
                oldCode = p.hashCode();
            }
        }
    }

    @SmallTest
    public void testMappedAddressesAreBroken() {
        // 192.0.2.0/24 != ::ffff:c000:0204/120, but because we use InetAddress,
        // we are unable to comprehend that.
        byte[] ipv6bytes = {
            (byte) 0, (byte) 0, (byte) 0, (byte) 0,
            (byte) 0, (byte) 0, (byte) 0, (byte) 0,
            (byte) 0, (byte) 0, (byte) 0xff, (byte) 0xff,
            (byte) 192, (byte) 0, (byte) 2, (byte) 0};
        IpPrefix p = new IpPrefix(ipv6bytes, 120);
        assertEquals(16, p.getRawAddress().length);       // Fine.
        assertArrayEquals(ipv6bytes, p.getRawAddress());  // Fine.

        // Broken.
        assertEquals("192.0.2.0/120", p.toString());
        assertEquals(InetAddress.parseNumericAddress("192.0.2.0"), p.getAddress());
    }

    public IpPrefix passThroughParcel(IpPrefix p) {
        Parcel parcel = Parcel.obtain();
        IpPrefix p2 = null;
        try {
            p.writeToParcel(parcel, 0);
            parcel.setDataPosition(0);
            p2 = IpPrefix.CREATOR.createFromParcel(parcel);
        } finally {
            parcel.recycle();
        }
        assertNotNull(p2);
        return p2;
    }

    public void assertParcelingIsLossless(IpPrefix p) {
      IpPrefix p2 = passThroughParcel(p);
      assertEquals(p, p2);
    }

    public void testParceling() {
        IpPrefix p;

        p = new IpPrefix("2001:4860:db8::/64");
        assertParcelingIsLossless(p);

        p = new IpPrefix("192.0.2.0/25");
        assertParcelingIsLossless(p);
    }
}