// Copyright (C) 2010-2015 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 <vector>
#include <sstream>

#include <exceptions/exceptions.h>

#include <util/buffer.h>
#include <dns/exceptions.h>
#include <dns/messagerenderer.h>
#include <dns/name.h>
#include <dns/question.h>
#include <dns/rrclass.h>
#include <dns/rrtype.h>

#include <gtest/gtest.h>

#include <dns/tests/unittest_util.h>
#include <util/unittests/wiredata.h>

using namespace std;
using namespace isc::dns;
using namespace isc::util;
using isc::UnitTestUtil;
using isc::util::unittests::matchWireData;

namespace {
class QuestionTest : public ::testing::Test {
protected:
    QuestionTest() : obuffer(0),
                     example_name1(Name("foo.example.com")),
                     example_name2(Name("bar.example.com")),
                     test_question1(example_name1, RRClass::IN(),
                                    RRType::NS()),
                     test_question2(example_name2, RRClass::CH(),
                                    RRType::A())
    {}
    OutputBuffer obuffer;
    MessageRenderer renderer;
    Name example_name1;
    Name example_name2;
    Question test_question1;
    Question test_question2;
    vector<unsigned char> wiredata;
};

Question
questionFromWire(const char* datafile, size_t position = 0) {
    vector<unsigned char> data;
    UnitTestUtil::readWireData(datafile, data);

    InputBuffer buffer(&data[0], data.size());
    buffer.setPosition(position);

    return (Question(buffer));
}

TEST_F(QuestionTest, fromWire) {
    Question q = questionFromWire("question_fromWire");

    EXPECT_EQ(example_name1, q.getName());
    EXPECT_EQ(RRClass::IN(), q.getClass());
    EXPECT_EQ(RRType::NS(), q.getType());

    // owner name of the second Question is compressed.  It's uncommon
    // (to have multiple questions), but isn't prohibited by the protocol.
    q = questionFromWire("question_fromWire", 21);
    EXPECT_EQ(example_name2, q.getName());
    EXPECT_EQ(RRClass::CH(), q.getClass());
    EXPECT_EQ(RRType::A(), q.getType());

    // Pathological cases: Corresponding exceptions will be thrown from
    // the underlying parser.
    EXPECT_THROW(questionFromWire("question_fromWire", 31), DNSMessageFORMERR);
    EXPECT_THROW(questionFromWire("question_fromWire", 36), IncompleteRRClass);
}

TEST_F(QuestionTest, toText) {
    EXPECT_EQ("foo.example.com. IN NS", test_question1.toText());
    EXPECT_EQ("bar.example.com. CH A", test_question2.toText());

    EXPECT_EQ("foo.example.com. IN NS", test_question1.toText(false));
    EXPECT_EQ("bar.example.com. CH A", test_question2.toText(false));

    EXPECT_EQ("foo.example.com. IN NS\n", test_question1.toText(true));
    EXPECT_EQ("bar.example.com. CH A\n", test_question2.toText(true));
}

TEST_F(QuestionTest, toWireBuffer) {
    test_question1.toWire(obuffer);
    test_question2.toWire(obuffer);
    UnitTestUtil::readWireData("question_toWire1", wiredata);
    matchWireData(&wiredata[0], wiredata.size(),
                  obuffer.getData(), obuffer.getLength());
}

TEST_F(QuestionTest, toWireRenderer) {
    test_question1.toWire(renderer);
    test_question2.toWire(renderer);
    UnitTestUtil::readWireData("question_toWire2", wiredata);
    matchWireData(&wiredata[0], wiredata.size(),
                  renderer.getData(), renderer.getLength());
}

TEST_F(QuestionTest, toWireTruncated) {
    // If the available length in the renderer is too small, it would require
    // truncation.  This won't happen in normal cases, but protocol wise it
    // could still happen if and when we support some (possibly future) opcode
    // that allows multiple questions.

    // Set the length limit to the qname length so that the whole question
    // would request truncated
    renderer.setLengthLimit(example_name1.getLength());

    EXPECT_FALSE(renderer.isTruncated()); // check pre-render condition
    EXPECT_EQ(0, test_question1.toWire(renderer));
    EXPECT_TRUE(renderer.isTruncated());
    EXPECT_EQ(0, renderer.getLength()); // renderer shouldn't have any data
}

// test operator<<.  We simply confirm it appends the result of toText().
TEST_F(QuestionTest, LeftShiftOperator) {
    ostringstream oss;
    oss << test_question1;
    EXPECT_EQ(test_question1.toText(), oss.str());
}

TEST_F(QuestionTest, comparison) {
    const Name a("a"), b("b");
    const RRClass in(RRClass::IN()), ch(RRClass::CH());
    const RRType ns(RRType::NS()), aaaa(RRType::AAAA());

    EXPECT_TRUE(Question(a, in, ns) < Question(a, in, aaaa));
    EXPECT_FALSE(Question(a, in, aaaa) < Question(a, in, ns));

    EXPECT_TRUE(Question(a, in, ns) < Question(a, ch, ns));
    EXPECT_FALSE(Question(a, ch, ns) < Question(a, in, ns));

    EXPECT_TRUE(Question(a, in, ns) < Question(a, ch, aaaa));
    EXPECT_FALSE(Question(a, ch, aaaa) < Question(a, in, ns));

    EXPECT_TRUE(Question(a, in, ns) < Question(b, in, ns));
    EXPECT_FALSE(Question(a, in, ns) < Question(a, in, ns));

    EXPECT_TRUE(Question(a, in, ns) < Question(b, ch, ns));
    EXPECT_FALSE(Question(b, ch, ns) < Question(a, in, ns));

    EXPECT_TRUE(Question(a, in, ns) < Question(b, ch, aaaa));
    EXPECT_FALSE(Question(b, ch, aaaa) < Question(a, in, ns));

    EXPECT_FALSE(Question(a, in, ns) < Question(a, in, ns));
    EXPECT_FALSE(Question(a, ch, ns) < Question(a, ch, ns));
    EXPECT_FALSE(Question(b, in, ns) < Question(b, in, ns));
    EXPECT_FALSE(Question(b, in, aaaa) < Question(b, in, aaaa));

    // Identical questions are equal

    EXPECT_TRUE(Question(a, in, ns) == Question(a, in, ns));
    EXPECT_FALSE(Question(a, in, ns) != Question(a, in, ns));

    // Components differing by one component are unequal...

    EXPECT_FALSE(Question(b, in, ns) == Question(a, in, ns));
    EXPECT_TRUE(Question(b, in, ns) != Question(a, in, ns));

    EXPECT_FALSE(Question(a, ch, ns) == Question(a, in, ns));
    EXPECT_TRUE(Question(a, ch, ns) != Question(a, in, ns));

    EXPECT_FALSE(Question(a, in, aaaa) == Question(a, in, ns));
    EXPECT_TRUE(Question(a, in, aaaa) != Question(a, in, ns));

    // ... as are those differing by two components

    EXPECT_FALSE(Question(b, ch, ns) == Question(a, in, ns));
    EXPECT_TRUE(Question(b, ch, ns) != Question(a, in, ns));

    EXPECT_FALSE(Question(b, in, aaaa) == Question(a, in, ns));
    EXPECT_TRUE(Question(b, in, aaaa) != Question(a, in, ns));

    EXPECT_FALSE(Question(a, ch, aaaa) == Question(a, in, ns));
    EXPECT_TRUE(Question(a, ch, aaaa) != Question(a, in, ns));

    // ... and question differing by all three

    EXPECT_FALSE(Question(b, ch, aaaa) == Question(a, in, ns));
    EXPECT_TRUE(Question(b, ch, aaaa) != Question(a, in, ns));

}

}