/*
 * Copyright 2018, Oath Inc. Licensed under the terms of the
 * Apache License 2.0. See LICENSE file at the project root for terms.
 */

#include "hll.hpp"
#include "HllArray.hpp"
#include "HllSketch.hpp"

#include <exception>
#include <sstream>
#include <cppunit/TestFixture.h>
#include <cppunit/extensions/HelperMacros.h>

namespace datasketches {

class HllArrayTest : public CppUnit::TestFixture {

  CPPUNIT_TEST_SUITE(HllArrayTest);
  CPPUNIT_TEST(checkCompositeEstimate);
  CPPUNIT_TEST(checkSerializeDeserialize);
  CPPUNIT_TEST(checkIsCompact);
  CPPUNIT_TEST(checkCorruptBytearray);
  CPPUNIT_TEST(checkCorruptStream);
  CPPUNIT_TEST_SUITE_END();

  void testComposite(const int lgK, const TgtHllType tgtHllType, const int n) {
    hll_union u = HllUnion::newInstance(lgK);
    hll_sketch sk = HllSketch::newInstance(lgK, tgtHllType);
    for (int i = 0; i < n; ++i) {
      u->update(i);
      sk->update(i);
    }
    u->update(*sk); // merge
    hll_sketch res = u->getResult(TgtHllType::HLL_8);
    double est = res->getCompositeEstimate();
    CPPUNIT_ASSERT_DOUBLES_EQUAL(est, sk->getCompositeEstimate(), 0.0);
  }

  void checkCompositeEstimate() {
    testComposite(4, TgtHllType::HLL_8, 10000);
    testComposite(5, TgtHllType::HLL_8, 10000);
    testComposite(6, TgtHllType::HLL_8, 10000);
    testComposite(13, TgtHllType::HLL_8, 10000);
  }

  void checkSerializeDeserialize() {
    int lgK = 4;
    int n = 8;
    serializeDeserialize(lgK, HLL_4, n);
    serializeDeserialize(lgK, HLL_6, n);
    serializeDeserialize(lgK, HLL_8, n);

    lgK = 15;
    n = (((1 << (lgK - 3))*3)/4) + 100;
    serializeDeserialize(lgK, HLL_4, n);
    serializeDeserialize(lgK, HLL_6, n);
    serializeDeserialize(lgK, HLL_8, n);

    lgK = 21;
    n = (((1 << (lgK - 3))*3)/4) + 1000;
    serializeDeserialize(lgK, HLL_4, n);
    serializeDeserialize(lgK, HLL_6, n);
    serializeDeserialize(lgK, HLL_8, n);
  }

  void serializeDeserialize(const int lgK, TgtHllType tgtHllType, const int n) {
    hll_sketch sk1 = HllSketch::newInstance(lgK, tgtHllType);

    for (int i = 0; i < n; ++i) {
      sk1->update(i);
    }
    CPPUNIT_ASSERT(static_cast<HllSketchPvt*>(sk1.get())->getCurrentMode() == CurMode::HLL);

    double est1 = sk1->getEstimate();
    CPPUNIT_ASSERT_DOUBLES_EQUAL(n, est1, n * 0.03);

    // serialize as compact and updatable, deserialize, compare estimates are exact
    std::stringstream ss(std::ios::in | std::ios::out | std::ios::binary);
    sk1->serializeCompact(ss);
    hll_sketch sk2 = HllSketch::deserialize(ss);
    CPPUNIT_ASSERT_DOUBLES_EQUAL(sk2->getEstimate(), sk1->getEstimate(), 0.0);

    ss.clear();
    sk1->serializeUpdatable(ss);
    sk2 = HllSketch::deserialize(ss);
    CPPUNIT_ASSERT_DOUBLES_EQUAL(sk2->getEstimate(), sk1->getEstimate(), 0.0);

    sk1->reset();
    CPPUNIT_ASSERT_DOUBLES_EQUAL(0.0, sk1->getEstimate(), 0.0);
  }

  void checkIsCompact() {
    hll_sketch sk = HllSketch::newInstance(4);
    for (int i = 0; i < 8; ++i) {
      sk->update(i);
    }
    CPPUNIT_ASSERT(!sk->isCompact());
  }

  void checkCorruptBytearray() {
    int lgK = 8;
    hll_sketch sk1 = HllSketch::newInstance(lgK, HLL_8);
    for (int i = 0; i < 50; ++i) {
      sk1->update(i);
    }
    std::pair<std::unique_ptr<uint8_t[]>, size_t> sketchBytes = sk1->serializeCompact();
    uint8_t* bytes = sketchBytes.first.get();

    bytes[HllUtil::PREAMBLE_INTS_BYTE] = 0;
    CPPUNIT_ASSERT_THROW_MESSAGE("Failed to detect error in preInts byte",
                                 HllSketch::deserialize(bytes, sketchBytes.second),
                                 std::invalid_argument);
    CPPUNIT_ASSERT_THROW_MESSAGE("Failed to detect error in preInts byte",
                                 HllArray::newHll(bytes, sketchBytes.second),
                                 std::invalid_argument);
    bytes[HllUtil::PREAMBLE_INTS_BYTE] = HllUtil::HLL_PREINTS;

    bytes[HllUtil::SER_VER_BYTE] = 0;
    CPPUNIT_ASSERT_THROW_MESSAGE("Failed to detect error in serialization version byte",
                                 HllSketch::deserialize(bytes, sketchBytes.second),
                                 std::invalid_argument);
    bytes[HllUtil::SER_VER_BYTE] = HllUtil::SER_VER;

    bytes[HllUtil::FAMILY_BYTE] = 0;
    CPPUNIT_ASSERT_THROW_MESSAGE("Failed to detect error in family id byte",
                                 HllSketch::deserialize(bytes, sketchBytes.second),
                                 std::invalid_argument);
    bytes[HllUtil::FAMILY_BYTE] = HllUtil::FAMILY_ID;

    uint8_t tmp = bytes[HllUtil::MODE_BYTE];
    bytes[HllUtil::MODE_BYTE] = 0x10; // HLL_6, LIST
    CPPUNIT_ASSERT_THROW_MESSAGE("Failed to detect error in mode byte",
                                 HllSketch::deserialize(bytes, sketchBytes.second),
                                 std::invalid_argument);
    bytes[HllUtil::MODE_BYTE] = tmp;

    tmp = bytes[HllUtil::LG_ARR_BYTE];
    bytes[HllUtil::LG_ARR_BYTE] = 0;
    HllSketch::deserialize(bytes, sketchBytes.second);
    // should work fine despite the corruption
    bytes[HllUtil::LG_ARR_BYTE] = tmp;

    CPPUNIT_ASSERT_THROW_MESSAGE("Failed to detect error in serialized length",
                                 HllSketch::deserialize(bytes, sketchBytes.second - 1),
                                 std::invalid_argument);
    CPPUNIT_ASSERT_THROW_MESSAGE("Failed to detect error in serialized length",
                                 HllSketch::deserialize(bytes, 3),
                                 std::invalid_argument);
    }

  void checkCorruptStream() {
    int lgK = 6;
    hll_sketch sk1 = HllSketch::newInstance(lgK);
    for (int i = 0; i < 50; ++i) {
      sk1->update(i);
    }
    std::stringstream ss;
    sk1->serializeCompact(ss);

    ss.seekp(HllUtil::PREAMBLE_INTS_BYTE);
    ss.put(0);
    ss.seekg(0);
    CPPUNIT_ASSERT_THROW_MESSAGE("Failed to detect error in preInts byte",
                                 HllSketch::deserialize(ss),
                                 std::invalid_argument);
    CPPUNIT_ASSERT_THROW_MESSAGE("Failed to detect error in preInts byte",
                                 HllArray::newHll(ss),
                                 std::invalid_argument);                                
    ss.seekp(HllUtil::PREAMBLE_INTS_BYTE);
    ss.put(HllUtil::HLL_PREINTS);

    ss.seekp(HllUtil::SER_VER_BYTE);
    ss.put(0);
    ss.seekg(0);
    CPPUNIT_ASSERT_THROW_MESSAGE("Failed to detect error in serialization version byte",
                                 HllSketch::deserialize(ss),
                                 std::invalid_argument);
    ss.seekp(HllUtil::SER_VER_BYTE);
    ss.put(HllUtil::SER_VER);

    ss.seekp(HllUtil::FAMILY_BYTE);
    ss.put(0);
    ss.seekg(0);
    CPPUNIT_ASSERT_THROW_MESSAGE("Failed to detect error in family id byte",
                                 HllSketch::deserialize(ss),
                                 std::invalid_argument);
    ss.seekp(HllUtil::FAMILY_BYTE);
    ss.put(HllUtil::FAMILY_ID);

    ss.seekg(HllUtil::MODE_BYTE);
    uint8_t tmp = ss.get();
    ss.seekp(HllUtil::MODE_BYTE);
    ss.put(0x11); // HLL_6, SET
    ss.seekg(0);
    CPPUNIT_ASSERT_THROW_MESSAGE("Failed to detect error in mode byte",
                                 HllSketch::deserialize(ss),
                                 std::invalid_argument);
    ss.seekp(HllUtil::MODE_BYTE);
    ss.put(tmp);

    ss.seekg(HllUtil::LG_ARR_BYTE);
    tmp = ss.get();
    ss.seekp(HllUtil::LG_ARR_BYTE);
    ss.put(0);
    ss.seekg(0);
    HllSketch::deserialize(ss);
    // should work fine despite the corruption
    ss.seekp(HllUtil::LG_ARR_BYTE);
    ss.put(tmp);
  }

};

CPPUNIT_TEST_SUITE_REGISTRATION(HllArrayTest);

} /* namespace datasketches */