// Copyright (C) 2013-2023 Internet Systems Consortium, Inc. ("ISC")
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at http://mozilla.org/MPL/2.0/.

#include <config.h>

#include <dhcp_ddns/ncr_io.h>
#include <dhcp/duid.h>
#include <dhcp/hwaddr.h>
#include <util/time_utilities.h>

#include <testutils/gtest_utils.h>
#include <gtest/gtest.h>
#include <algorithm>

using namespace std;
using namespace isc;
using namespace isc::dhcp_ddns;
using namespace isc::dhcp;

namespace {

/// @brief Defines a list of valid JSON NameChangeRequest renditions.
/// They are used as input to test conversion from JSON.
const char *valid_msgs[] =
{
    // Valid Add.
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"010203040A7F8E3D\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300, "
     " \"use-conflict-resolution\": true"
     "}",
    // Valid Remove.
     "{"
     " \"change-type\" : 1 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"010203040A7F8E3D\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300, "
     " \"use-conflict-resolution\": true"
     "}",
     // Valid Add with IPv6 address
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"fe80::2acf:e9ff:fe12:e56f\" , "
     " \"dhcid\" : \"010203040A7F8E3D\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300, "
     " \"use-conflict-resolution\": true"
     "}",
    // Missing use-conflict-resolution
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"010203040A7F8E3D\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300 "
     "}"
};

/// @brief Defines a list of invalid JSON NameChangeRequest renditions.
/// They are used as input to test conversion from JSON.
const char *invalid_msgs[] =
{
    // Invalid change type.
     "{"
     " \"change-type\" : 7 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"010203040A7F8E3D\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300, "
     " \"use-conflict-resolution\": true"
     "}",
    // Invalid forward change.
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : \"bogus\" , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"010203040A7F8E3D\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300, "
     " \"use-conflict-resolution\": true"
     "}",
    // Invalid reverse change.
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : 500 , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"010203040A7F8E3D\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300, "
     " \"use-conflict-resolution\": true"
     "}",
    // Forward and reverse change both false.
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : false , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"010203040A7F8E3D\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300, "
     " \"use-conflict-resolution\": true"
     "}",
    // Blank FQDN
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"010203040A7F8E3D\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300, "
     " \"use-conflict-resolution\": true"
     "}",
    // Malformed FQDN
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \".bad_name\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"010203040A7F8E3D\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300, "
     " \"use-conflict-resolution\": true"
     "}",
    // Bad IP address
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"xxxxxx\" , "
     " \"dhcid\" : \"010203040A7F8E3D\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300 "
     " \"use-conflict-resolution\": true"
     "}",
    // Blank DHCID
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300, "
     " \"use-conflict-resolution\": true"
     "}",
    // Odd number of digits in DHCID
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"010203040A7F8E3\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300, "
     " \"use-conflict-resolution\": true"
     "}",
    // Text in DHCID
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"THIS IS BOGUS!!!\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300, "
     " \"use-conflict-resolution\": true"
     "}",
    // Invalid lease expiration string
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"010203040A7F8E3D\" , "
     " \"lease-expires-on\" : \"Wed Jun 26 13:46:46 EDT 2013\" , "
     " \"lease-length\" : 1300, "
     " \"use-conflict-resolution\": true"
     "}",
    // Non-integer for lease length.
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"010203040A7F8E3D\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : \"BOGUS\", "
     " \"use-conflict-resolution\": true"
     "}",
    // Invalid use-conflict-resolution
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"010203040A7F8E3D\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300, "
     " \"use-conflict-resolution\": 777"
     "}"
};

/// @brief Tests the NameChangeRequest constructors.
/// This test verifies that:
/// 1. Default constructor works.
/// 2. "Full" constructor, when given valid parameter values, works.
/// 3. "Full" constructor, given a blank FQDN fails
/// 4. "Full" constructor, given an invalid IP Address FQDN fails
/// 5. "Full" constructor, given a blank DHCID fails
/// 6. "Full" constructor, given false for both forward and reverse fails
TEST(NameChangeRequestTest, constructionTests) {
    // Verify the default constructor works.
    NameChangeRequestPtr ncr;
    EXPECT_NO_THROW(ncr.reset(new NameChangeRequest()));
    EXPECT_TRUE(ncr);

    // Verify that full constructor works.
    uint64_t expiry = isc::util::detail::gettimeWrapper();
    D2Dhcid dhcid("010203040A7F8E3D");

    EXPECT_NO_THROW(ncr.reset(new NameChangeRequest(
                    CHG_ADD, true, true, "walah.walah.com",
                    "192.168.1.101", dhcid, expiry, 1300)));
    EXPECT_TRUE(ncr);
    ncr.reset();

    // Verify blank FQDN is detected.
    EXPECT_THROW(NameChangeRequest(CHG_ADD, true, true, "",
                 "192.168.1.101", dhcid, expiry, 1300), NcrMessageError);

    // Verify that an invalid IP address is detected.
    EXPECT_THROW(NameChangeRequest(CHG_ADD, true, true, "valid.fqdn",
                 "xxx.168.1.101", dhcid, expiry, 1300), NcrMessageError);

    // Verify that a blank DHCID is detected.
    D2Dhcid blank_dhcid;
    EXPECT_THROW(NameChangeRequest(CHG_ADD, true, true, "walah.walah.com",
                 "192.168.1.101", blank_dhcid, expiry, 1300), NcrMessageError);

    // Verify that one or both of direction flags must be true.
    EXPECT_THROW(NameChangeRequest(CHG_ADD, false, false, "valid.fqdn",
                "192.168.1.101", dhcid, expiry, 1300), NcrMessageError);

}

/// @brief Tests the basic workings of D2Dhcid to and from string conversions.
/// It verifies that:
/// 1. DHCID input strings must contain an even number of characters
/// 2. DHCID input strings must contain only hexadecimal character digits
/// 3. A valid DHCID string converts correctly.
/// 4. Converting a D2Dhcid to a string works correctly.
/// 5. Equality, inequality, and less-than-equal operators work.
TEST(NameChangeRequestTest, dhcidTest) {
    D2Dhcid dhcid;

    // Odd number of digits should be rejected.
    std::string test_str = "010203040A7F8E3";
    EXPECT_THROW(dhcid.fromStr(test_str), NcrMessageError);

    // Non digit content should be rejected.
    test_str = "0102BOGUSA7F8E3D";
    EXPECT_THROW(dhcid.fromStr(test_str), NcrMessageError);

    // Verify that valid input converts into a proper byte array.
    test_str = "010203040A7F8E3D";
    ASSERT_NO_THROW(dhcid.fromStr(test_str));

    // Create a test vector of expected byte contents.
    const uint8_t bytes[] = { 0x1, 0x2, 0x3, 0x4, 0xA, 0x7F, 0x8E, 0x3D };
    std::vector<uint8_t> expected_bytes(bytes, bytes + sizeof(bytes));

    // Fetch the byte vector from the dhcid and verify if equals the expected
    // content.
    const std::vector<uint8_t>& converted_bytes = dhcid.getBytes();
    EXPECT_EQ(expected_bytes.size(), converted_bytes.size());
    EXPECT_TRUE (std::equal(expected_bytes.begin(),
                            expected_bytes.begin()+expected_bytes.size(),
                            converted_bytes.begin()));

    // Convert the new dhcid back to string and verify it matches the original
    // DHCID input string.
    std::string next_str = dhcid.toStr();
    EXPECT_EQ(test_str, next_str);

    // Test equality, inequality, and less-than-equal operators
    test_str="AABBCCDD";
    EXPECT_NO_THROW(dhcid.fromStr(test_str));

    D2Dhcid other_dhcid;
    EXPECT_NO_THROW(other_dhcid.fromStr(test_str));

    EXPECT_TRUE(dhcid == other_dhcid);
    EXPECT_FALSE(dhcid != other_dhcid);

    EXPECT_NO_THROW(other_dhcid.fromStr("BBCCDDEE"));
    EXPECT_TRUE(dhcid < other_dhcid);

}

/// @brief Test fixture class for testing DHCID creation.
class DhcidTest : public ::testing::Test {
public:
    /// @brief Constructor
    DhcidTest() {
        // 0x000000066d79686f7374076578616d706c6503636f6d00
        const uint8_t fqdn_data[] = {
            6, 109, 121, 104, 111, 115, 116,     // myhost.
            7, 101, 120, 97, 109, 112, 108, 101, // example.
            3, 99, 111, 109, 0                   // com.
        };
        wire_fqdn_.assign(fqdn_data, fqdn_data + sizeof(fqdn_data));
    }

    /// @brief Destructor
    virtual ~DhcidTest() {
    }

    std::vector<uint8_t> wire_fqdn_;
};

/// Tests that DHCID is correctly created from a DUID and FQDN. The final format
/// of the DHCID is as follows:
/// <identifier-type> <digest-type-code> <digest>
/// where:
/// - identifier-type (2 octets) is 0x0002.
/// - digest-type-code (1 octet) indicates SHA-256 hashing and is equal 0x1.
/// - digest = SHA-256(<DUID> <FQDN>)
/// Note: FQDN is given in the on-wire canonical format.
TEST_F(DhcidTest, fromDUID) {
    D2Dhcid dhcid;

    // Create DUID.
    uint8_t duid_data[] = { 0, 1, 2, 3, 4, 5, 6 };
    DUID duid(duid_data, sizeof(duid_data));

    // Create DHCID.
    ASSERT_NO_THROW(dhcid.fromDUID(duid, wire_fqdn_));

    // The reference DHCID (represented as string of hexadecimal digits)
    // has been calculated using one of the online calculators.
    std::string dhcid_ref = "0002012191B7B21AF97E0E656DF887C5E2D"
        "EF30E7758A207EDF4CCB2DE8CA37066021C";

    // Make sure that the DHCID is valid.
    EXPECT_EQ(dhcid_ref, dhcid.toStr());
}

// Test that DHCID is correctly created when the DUID has minimal length (1).
TEST_F(DhcidTest, fromMinDUID) {
    D2Dhcid dhcid;

    // Create DUID.
    std::vector<uint8_t> duid_data(DUID::MIN_DUID_LEN, 1);
    DUID duid(duid_data.data(), duid_data.size());

    // Create DHCID.
    ASSERT_NO_THROW(dhcid.fromDUID(duid, wire_fqdn_));

    // The reference DHCID (represented as string of hexadecimal digits)
    // has been calculated using one of the online calculators.
    std::string dhcid_ref = "000201202F813E7D9C88BADA41250F2A662"
        "97742BB9B3EB37C0981D4A905745A30BDD3";

    // Make sure that the DHCID is valid.
    EXPECT_EQ(dhcid_ref, dhcid.toStr());
}

// Test that DHCID is correctly created when the DUID has maximal length (128).
TEST_F(DhcidTest, fromMaxDUID) {
    D2Dhcid dhcid;

    // Create DUID.
    std::vector<uint8_t> duid_data(DUID::MAX_DUID_LEN, 1);
    DUID duid(&duid_data[0], duid_data.size());

    // Create DHCID.
    ASSERT_NO_THROW(dhcid.fromDUID(duid, wire_fqdn_));

    // The reference DHCID (represented as string of hexadecimal digits)
    // has been calculated using one of the online calculators.
    std::string dhcid_ref = "0002015B9022851B4015AD78187BB9BDB98"
        "7708C5EEA74140B28095ED36FE1EAFEE3F6";

    // Make sure that the DHCID is valid.
    EXPECT_EQ(dhcid_ref, dhcid.toStr());
}

// This test verifies that DHCID is properly computed from a buffer holding
// client identifier data.
TEST_F(DhcidTest, fromClientId) {
    D2Dhcid dhcid;

    // Create a buffer holding client id..
    uint8_t clientid_data[] = { 0, 1, 2, 3, 4, 5, 6 };
    std::vector<uint8_t> clientid(clientid_data,
                                  clientid_data + sizeof(clientid_data));

    // Create DHCID.
    ASSERT_NO_THROW(dhcid.fromClientId(clientid, wire_fqdn_));

    // The reference DHCID (represented as string of hexadecimal digits)
    // has been calculated using one of the online calculators.
    std::string dhcid_ref = "0001012191B7B21AF97E0E656DF887C5E2D"
        "EF30E7758A207EDF4CCB2DE8CA37066021C";

    // Make sure that the DHCID is valid.
    EXPECT_EQ(dhcid_ref, dhcid.toStr());

    // Make sure that the empty FQDN is not accepted.
    std::vector<uint8_t> empty_wire_fqdn;
    EXPECT_THROW(dhcid.fromClientId(clientid, empty_wire_fqdn),
                 isc::dhcp_ddns::DhcidRdataComputeError);

    // Make sure that the empty client identifier is not accepted.
    clientid.clear();
    EXPECT_THROW(dhcid.fromClientId(clientid, wire_fqdn_),
                 isc::dhcp_ddns::DhcidRdataComputeError);


}

// This test verifies that DHCID is properly computed from a buffer holding
// client identifier data that contains a DUID.
TEST_F(DhcidTest, fromClientIdDUID) {
    D2Dhcid dhcid;

    // Create a buffer holding client id..
    uint8_t clientid_data[] = { 0xff, 0x5d, 0xe2, 0x6c, 0x15, 0x00, 0x02,
        0x00, 0x00, 0xab, 0x11, 0x9a, 0x57, 0x20, 0x95, 0x71, 0x61, 0xbd, 0xd0 };
    std::vector<uint8_t> clientid(clientid_data,
                                  clientid_data + sizeof(clientid_data));

    // Create DHCID.
    ASSERT_NO_THROW(dhcid.fromClientId(clientid, wire_fqdn_));

    // The reference DHCID (represented as string of hexadecimal digits)
    std::string dhcid_ref = "000201A250D060B9352AE68E5014B78D25"
        "1C30EFB0D5F64E48303B2BC56E6938F129E7";

    // Make sure that the DHCID is valid.
    EXPECT_EQ(dhcid_ref, dhcid.toStr());

    // Make sure that a too long client identifier is not accepted.
    clientid.resize(136);
    EXPECT_THROW_MSG(dhcid.fromClientId(clientid, wire_fqdn_),
                     isc::dhcp_ddns::DhcidRdataComputeError,
                     "unable to compute DHCID from client identifier,"
                     " embedded DUID length of: 136, is too long");

    // Make sure that a too short client identifier is not accepted.
    clientid.resize(5);
    EXPECT_THROW_MSG(dhcid.fromClientId(clientid, wire_fqdn_),
                     isc::dhcp_ddns::DhcidRdataComputeError,
                     "unable to compute DHCID from client identifier,"
                     " embedded DUID length of: 5, is too short");

    // Make sure an empty client identifier is not accepted.
    clientid.clear();
    EXPECT_THROW_MSG(dhcid.fromClientId(clientid, wire_fqdn_),
                     isc::dhcp_ddns::DhcidRdataComputeError,
                     "empty DUID used to create DHCID");
}

// This test verifies that DHCID is properly computed from a HW address.
TEST_F(DhcidTest, fromHWAddr) {
    D2Dhcid dhcid;

    // Create a buffer holding client id..
    uint8_t hwaddr_data[] = { 0, 1, 2, 3, 4, 5, 6 };
    HWAddrPtr hwaddr(new HWAddr(hwaddr_data, sizeof(hwaddr_data),
                                HTYPE_ETHER));

    // Create DHCID.
    ASSERT_NO_THROW(dhcid.fromHWAddr(hwaddr, wire_fqdn_));

    // The reference DHCID (represented as string of hexadecimal digits)
    // has been calculated using one of the online calculators.
    std::string dhcid_ref = "0000012247F6DC4423C3E8627434A9D686860"
        "9D88948F78018B215EDCAA30C0C135035";

    // Make sure that the DHCID is valid.
    EXPECT_EQ(dhcid_ref, dhcid.toStr());

    // Make sure that the empty FQDN is not accepted.
    std::vector<uint8_t> empty_wire_fqdn;
    EXPECT_THROW(dhcid.fromHWAddr(hwaddr, empty_wire_fqdn),
                 isc::dhcp_ddns::DhcidRdataComputeError);

    // Make sure that the NULL HW address is not accepted.
    hwaddr.reset();
    EXPECT_THROW(dhcid.fromHWAddr(hwaddr, wire_fqdn_),
                 isc::dhcp_ddns::DhcidRdataComputeError);
}

// test operator<< on D2Dhcid
TEST(NameChangeRequestTest, leftShiftOperation) {
    const D2Dhcid dhcid("010203040A7F8E3D");

    ostringstream oss;
    oss << dhcid;
    EXPECT_EQ(dhcid.toStr(), oss.str());
}

/// @brief Verifies the fundamentals of converting from and to JSON.
/// It verifies that:
/// 1. A NameChangeRequest can be created from a valid JSON string.
/// 2. A valid JSON string can be created from a NameChangeRequest
TEST(NameChangeRequestTest, basicJsonTest) {
    // Define valid JSON rendition of a request.
    std::string msg_str = "{"
                            "\"change-type\":1,"
                            "\"forward-change\":true,"
                            "\"reverse-change\":false,"
                            "\"fqdn\":\"walah.walah.com.\","
                            "\"ip-address\":\"192.168.2.1\","
                            "\"dhcid\":\"010203040A7F8E3D\","
                            "\"lease-expires-on\":\"20130121132405\","
                            "\"lease-length\":1300,"
                            "\"use-conflict-resolution\":true"
                          "}";

    // Verify that a NameChangeRequests can be instantiated from the
    // a valid JSON rendition.
    NameChangeRequestPtr ncr;
    ASSERT_NO_THROW_LOG(ncr  = NameChangeRequest::fromJSON(msg_str));
    ASSERT_TRUE(ncr);

    // Verify that the JSON string created by the new request equals the
    // original input string.
    std::string json_str = ncr->toJSON();
    EXPECT_EQ(msg_str, json_str);

    // Verify that the request ID matches the string from the DHCID.
    std::string dhcid_str = "010203040A7F8E3D";
    EXPECT_EQ(dhcid_str, ncr->getRequestId());
}

/// @brief Tests a variety of invalid JSON message strings.
/// This test iterates over a list of JSON messages, each containing a single
/// content error. The list of messages is defined by the global array,
/// invalid_messages. Currently that list contains the following invalid
/// conditions:
///  1. Invalid change type
///  2. Invalid forward change
///  3. Invalid reverse change
///  4. Forward and reverse change both false
///  5. Invalid forward change
///  6. Blank FQDN
///  7. Bad IP address
///  8. Blank DHCID
///  9. Odd number of digits in DHCID
/// 10. Text in DHCID
/// 11. Invalid lease expiration string
/// 12. Non-integer for lease length.
/// If more permutations arise they can easily be added to the list.
TEST(NameChangeRequestTest, invalidMsgChecks) {
    // Iterate over the list of JSON strings, attempting to create a
    // NameChangeRequest. The attempt should throw a NcrMessageError.
    int num_msgs = sizeof(invalid_msgs)/sizeof(char*);
    for (int i = 0; i < num_msgs; i++) {
        EXPECT_THROW(NameChangeRequest::fromJSON(invalid_msgs[i]),
                     NcrMessageError) << "Invalid message not caught idx: "
                     << i << std::endl << " text:[" << invalid_msgs[i] << "]"
                     << std::endl;
    }
}

/// @brief Tests a variety of valid JSON message strings.
/// This test iterates over a list of JSON messages, each containing a single
/// valid request rendition. The list of messages is defined by the global
/// array, valid_messages. Currently that list contains the following valid
/// messages:
///  1. Valid, IPv4 Add
///  2. Valid, IPv4 Remove
///  3. Valid, IPv6 Add
/// If more permutations arise they can easily be added to the list.
TEST(NameChangeRequestTest, validMsgChecks) {
    // Iterate over the list of JSON strings, attempting to create a
    // NameChangeRequest. The attempt should succeed.
    int num_msgs = sizeof(valid_msgs)/sizeof(char*);
    for (int i = 0; i < num_msgs; i++) {
        EXPECT_NO_THROW(NameChangeRequest::fromJSON(valid_msgs[i]))
                        << "Valid message failed,  message idx: " << i
                        << std::endl << " text:[" << valid_msgs[i] << "]"
                        << std::endl;
    }
}

/// @brief Tests converting to and from JSON via isc::util buffer classes.
/// This test verifies that:
/// 1. A NameChangeRequest can be rendered in JSON written to an OutputBuffer
/// 2. A InputBuffer containing a valid JSON request rendition can be used
/// to create a NameChangeRequest.
TEST(NameChangeRequestTest, toFromBufferTest) {
    // Define a string containing a valid JSON NameChangeRequest rendition.
    std::string msg_str = "{"
                            "\"change-type\":1,"
                            "\"forward-change\":true,"
                            "\"reverse-change\":false,"
                            "\"fqdn\":\"walah.walah.com.\","
                            "\"ip-address\":\"192.168.2.1\","
                            "\"dhcid\":\"010203040A7F8E3D\","
                            "\"lease-expires-on\":\"20130121132405\","
                            "\"lease-length\":1300,"
                            "\"use-conflict-resolution\":true"
                          "}";

    // Create a request from JSON directly.
    NameChangeRequestPtr ncr;
    ASSERT_NO_THROW(ncr = NameChangeRequest::fromJSON(msg_str));

    // Verify that we output the request as JSON text to a buffer
    // without error.
    isc::util::OutputBuffer output_buffer(1024);
    ASSERT_NO_THROW(ncr->toFormat(FMT_JSON, output_buffer));

    // Make an InputBuffer from the OutputBuffer.
    isc::util::InputBuffer input_buffer(output_buffer.getData(),
                                        output_buffer.getLength());

    // Verify that we can create a new request from the InputBuffer.
    NameChangeRequestPtr ncr2;
    ASSERT_NO_THROW(ncr2 =
                    NameChangeRequest::fromFormat(FMT_JSON, input_buffer));

    // Convert the new request to JSON directly.
    std::string final_str = ncr2->toJSON();

    // Verify that the final string matches the original.
    ASSERT_EQ(final_str, msg_str);
}

/// @brief Tests ip address modification and validation
TEST(NameChangeRequestTest, ipAddresses) {
    NameChangeRequest ncr;

    // Verify that a valid IPv4 address works.
    ASSERT_NO_THROW(ncr.setIpAddress("192.168.1.1"));
    const asiolink::IOAddress& io_addr4 = ncr.getIpIoAddress();
    EXPECT_EQ(ncr.getIpAddress(), io_addr4.toText());
    EXPECT_TRUE(ncr.isV4());
    EXPECT_FALSE(ncr.isV6());

    // Verify that a valid IPv6 address works.
    ASSERT_NO_THROW(ncr.setIpAddress("2001:1::f3"));
    const asiolink::IOAddress& io_addr6 = ncr.getIpIoAddress();
    EXPECT_EQ(ncr.getIpAddress(), io_addr6.toText());
    EXPECT_FALSE(ncr.isV4());
    EXPECT_TRUE(ncr.isV6());

    // Verify that an invalid address fails.
    ASSERT_THROW(ncr.setIpAddress("x001:1::f3"),NcrMessageError);
}

/// @brief Tests conversion of NameChangeFormat between enum and strings.
TEST(NameChangeFormatTest, formatEnumConversion){
    ASSERT_EQ(stringToNcrFormat("JSON"), dhcp_ddns::FMT_JSON);
    ASSERT_EQ(stringToNcrFormat("jSoN"), dhcp_ddns::FMT_JSON);
    ASSERT_THROW(stringToNcrFormat("bogus"), isc::BadValue);

    ASSERT_EQ(ncrFormatToString(dhcp_ddns::FMT_JSON), "JSON");
}

/// @brief Tests conversion of NameChangeProtocol between enum and strings.
TEST(NameChangeProtocolTest, protocolEnumConversion){
    ASSERT_EQ(stringToNcrProtocol("UDP"), dhcp_ddns::NCR_UDP);
    ASSERT_EQ(stringToNcrProtocol("udP"), dhcp_ddns::NCR_UDP);
    ASSERT_EQ(stringToNcrProtocol("TCP"), dhcp_ddns::NCR_TCP);
    ASSERT_EQ(stringToNcrProtocol("Tcp"), dhcp_ddns::NCR_TCP);
    ASSERT_THROW(stringToNcrProtocol("bogus"), isc::BadValue);

    ASSERT_EQ(ncrProtocolToString(dhcp_ddns::NCR_UDP), "UDP");
    ASSERT_EQ(ncrProtocolToString(dhcp_ddns::NCR_TCP), "TCP");
}

TEST(NameChangeRequestTest, useConflictResolutionParsing) {
    std::string base_json =
     "{"
     " \"change-type\" : 0 , "
     " \"forward-change\" : true , "
     " \"reverse-change\" : false , "
     " \"fqdn\" : \"walah.walah.com\" , "
     " \"ip-address\" : \"192.168.2.1\" , "
     " \"dhcid\" : \"010203040A7F8E3D\" , "
     " \"lease-expires-on\" : \"20130121132405\" , "
     " \"lease-length\" : 1300 ";

    std::string its_true(base_json + ",\"use-conflict-resolution\": true}");
    NameChangeRequestPtr ncr;
    ASSERT_NO_THROW_LOG(ncr = NameChangeRequest::fromJSON(its_true));
    ASSERT_TRUE(ncr);
    EXPECT_TRUE(ncr->useConflictResolution());

    std::string its_false(base_json + ",\"use-conflict-resolution\": false}");
    ASSERT_NO_THROW_LOG(ncr = NameChangeRequest::fromJSON(its_false));
    ASSERT_TRUE(ncr);
    EXPECT_FALSE(ncr->useConflictResolution());

    std::string its_missing(base_json + "}");
    ASSERT_NO_THROW_LOG(ncr = NameChangeRequest::fromJSON(its_true));
    ASSERT_TRUE(ncr);
    EXPECT_TRUE(ncr->useConflictResolution());
}

} // end of anonymous namespace