/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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.
 **/

#include <cstddef>
#include <cstdint>
#include <memory>
#include <vector>

#include "catalog/CatalogTypedefs.hpp"
#include "expressions/aggregation/AggregateFunction.hpp"
#include "expressions/aggregation/AggregateFunctionFactory.hpp"
#include "expressions/aggregation/AggregationHandle.hpp"
#include "expressions/aggregation/AggregationHandleAvg.hpp"
#include "expressions/aggregation/AggregationID.hpp"
#include "storage/AggregationOperationState.hpp"
#include "storage/PackedPayloadHashTable.hpp"
#include "storage/StorageManager.hpp"
#include "storage/ValueAccessorMultiplexer.hpp"
#include "types/CharType.hpp"
#include "types/DateOperatorOverloads.hpp"
#include "types/DatetimeIntervalType.hpp"
#include "types/DoubleType.hpp"
#include "types/FloatType.hpp"
#include "types/IntType.hpp"
#include "types/IntervalLit.hpp"
#include "types/LongType.hpp"
#include "types/Type.hpp"
#include "types/TypeFactory.hpp"
#include "types/TypeID.hpp"
#include "types/TypedValue.hpp"
#include "types/VarCharType.hpp"
#include "types/YearMonthIntervalType.hpp"
#include "types/containers/ColumnVector.hpp"
#include "types/containers/ColumnVectorsValueAccessor.hpp"

#include "gtest/gtest.h"

namespace quickstep {

class AggregationHandleAvgTest : public ::testing::Test {
 protected:
  static const int kNumSamples = 100;

  // Helper method that calls AggregationHandleAvg::iterateUnaryInl() to
  // aggregate 'value' into '*state'.
  void iterateHandle(AggregationState *state, const TypedValue &value) {
    static_cast<const AggregationHandleAvg &>(*aggregation_handle_avg_)
        .iterateUnaryInl(static_cast<AggregationStateAvg *>(state), value);
  }

  void initializeHandle(const Type &type) {
    aggregation_handle_avg_.reset(
        AggregateFunctionFactory::Get(AggregationID::kAvg)
            .createHandle(std::vector<const Type *>(1, &type)));
    aggregation_handle_avg_state_.reset(
        aggregation_handle_avg_->createInitialState());
  }

  static bool ApplyToTypesTest(TypeID typeID) {
    const Type &type =
        (typeID == kChar || typeID == kVarChar)
            ? TypeFactory::GetType(typeID, static_cast<std::size_t>(10))
            : TypeFactory::GetType(typeID);

    return AggregateFunctionFactory::Get(AggregationID::kAvg)
        .canApplyToTypes(std::vector<const Type *>(1, &type));
  }

  static bool ResultTypeForArgumentTypeTest(TypeID input_type_id,
                                            TypeID output_type_id) {
    const Type *result_type =
        AggregateFunctionFactory::Get(AggregationID::kAvg)
            .resultTypeForArgumentTypes(std::vector<const Type *>(
                1, &TypeFactory::GetType(input_type_id)));
    return (result_type->getTypeID() == output_type_id);
  }

  template <typename CppType>
  static void CheckAvgValue(CppType expected,
                            const AggregationHandle &handle,
                            const AggregationState &state) {
    EXPECT_EQ(expected, handle.finalize(state).getLiteral<CppType>());
  }

  template <typename CppType>
  static void CheckAvgValue(CppType expected, const TypedValue &value) {
    EXPECT_EQ(expected, value.getLiteral<CppType>());
  }

  // Static templated method for set a meaningful value to data types.
  template <typename CppType>
  static void SetDataType(int value, CppType *data) {
    *data = value;
  }

  template <typename GenericType, typename OutputType = DoubleType>
  void checkAggregationAvgGeneric() {
    const GenericType &type = GenericType::Instance(true);
    initializeHandle(type);
    EXPECT_TRUE(
        aggregation_handle_avg_->finalize(*aggregation_handle_avg_state_)
            .isNull());

    typename GenericType::cpptype val;
    typename GenericType::cpptype sum;
    SetDataType(0, &sum);

    iterateHandle(aggregation_handle_avg_state_.get(), type.makeNullValue());
    for (int i = 0; i < kNumSamples; ++i) {
      if (type.getTypeID() == kInt || type.getTypeID() == kLong) {
        SetDataType(i - 10, &val);
      } else {
        SetDataType(static_cast<float>(i - 10) / 10, &val);
      }
      iterateHandle(aggregation_handle_avg_state_.get(), type.makeValue(&val));
      sum += val;
    }
    iterateHandle(aggregation_handle_avg_state_.get(), type.makeNullValue());
    CheckAvgValue<typename OutputType::cpptype>(
        static_cast<typename OutputType::cpptype>(sum) / kNumSamples,
        *aggregation_handle_avg_,
        *aggregation_handle_avg_state_);

    // Test mergeStates().
    std::unique_ptr<AggregationState> merge_state(
        aggregation_handle_avg_->createInitialState());
    aggregation_handle_avg_->mergeStates(*merge_state,
                                         aggregation_handle_avg_state_.get());

    iterateHandle(merge_state.get(), type.makeNullValue());
    for (int i = 0; i < kNumSamples; ++i) {
      if (type.getTypeID() == kInt || type.getTypeID() == kLong) {
        SetDataType(i - 10, &val);
      } else {
        SetDataType(static_cast<float>(i - 10) / 10, &val);
      }
      iterateHandle(merge_state.get(), type.makeValue(&val));
      sum += val;
    }

    aggregation_handle_avg_->mergeStates(*merge_state,
                                         aggregation_handle_avg_state_.get());
    CheckAvgValue<typename OutputType::cpptype>(
        static_cast<typename OutputType::cpptype>(sum) / (2 * kNumSamples),
        *aggregation_handle_avg_,
        *aggregation_handle_avg_state_);
  }

  template <typename GenericType>
  ColumnVector* createColumnVectorGeneric(const Type &type,
                                          typename GenericType::cpptype *sum) {
    NativeColumnVector *column = new NativeColumnVector(type, kNumSamples + 3);

    typename GenericType::cpptype val;
    SetDataType(0, sum);

    column->appendTypedValue(type.makeNullValue());
    for (int i = 0; i < kNumSamples; ++i) {
      if (type.getTypeID() == kInt || type.getTypeID() == kLong) {
        SetDataType(i - 10, &val);
      } else {
        SetDataType(static_cast<float>(i - 10) / 10, &val);
      }
      column->appendTypedValue(type.makeValue(&val));
      *sum += val;
      // One NULL in the middle.
      if (i == kNumSamples / 2) {
        column->appendTypedValue(type.makeNullValue());
      }
    }
    column->appendTypedValue(type.makeNullValue());

    return column;
  }

  template <typename GenericType, typename OutputType = DoubleType>
  void checkAggregationAvgGenericValueAccessor() {
    const GenericType &type = GenericType::Instance(true);
    initializeHandle(type);
    EXPECT_TRUE(
        aggregation_handle_avg_->finalize(*aggregation_handle_avg_state_)
            .isNull());

    typename GenericType::cpptype sum;
    SetDataType(0, &sum);
    std::unique_ptr<ColumnVectorsValueAccessor> accessor(
        new ColumnVectorsValueAccessor());
    accessor->addColumn(createColumnVectorGeneric<GenericType>(type, &sum));

    std::unique_ptr<AggregationState> va_state(
        aggregation_handle_avg_->accumulateValueAccessor(
            {MultiSourceAttributeId(ValueAccessorSource::kBase, 0)},
            ValueAccessorMultiplexer(accessor.get())));

    // Test the state generated directly by accumulateValueAccessor(), and also
    // test after merging back.
    CheckAvgValue<typename OutputType::cpptype>(
        static_cast<typename OutputType::cpptype>(sum) / kNumSamples,
        *aggregation_handle_avg_,
        *va_state);

    aggregation_handle_avg_->mergeStates(*va_state,
                                         aggregation_handle_avg_state_.get());
    CheckAvgValue<typename OutputType::cpptype>(
        static_cast<typename OutputType::cpptype>(sum) / kNumSamples,
        *aggregation_handle_avg_,
        *aggregation_handle_avg_state_);
  }

  std::unique_ptr<AggregationHandle> aggregation_handle_avg_;
  std::unique_ptr<AggregationState> aggregation_handle_avg_state_;
  std::unique_ptr<StorageManager> storage_manager_;
};

const int AggregationHandleAvgTest::kNumSamples;

template <>
void AggregationHandleAvgTest::CheckAvgValue<double>(
    double expected,
    const AggregationHandle &handle,
    const AggregationState &state) {
  EXPECT_DOUBLE_EQ(expected, handle.finalize(state).getLiteral<double>());
}

template <>
void AggregationHandleAvgTest::SetDataType<DatetimeIntervalLit>(
    int value, DatetimeIntervalLit *data) {
  data->interval_ticks = value;
}

template <>
void AggregationHandleAvgTest::SetDataType<YearMonthIntervalLit>(
    int value, YearMonthIntervalLit *data) {
  data->months = value;
}

typedef AggregationHandleAvgTest AggregationHandleAvgDeathTest;

TEST_F(AggregationHandleAvgTest, IntTypeTest) {
  checkAggregationAvgGeneric<IntType>();
}

TEST_F(AggregationHandleAvgTest, LongTypeTest) {
  checkAggregationAvgGeneric<LongType>();
}

TEST_F(AggregationHandleAvgTest, FloatTypeTest) {
  checkAggregationAvgGeneric<FloatType>();
}

TEST_F(AggregationHandleAvgTest, DoubleTypeTest) {
  checkAggregationAvgGeneric<DoubleType>();
}

TEST_F(AggregationHandleAvgTest, DatetimeIntervalTypeTest) {
  checkAggregationAvgGeneric<DatetimeIntervalType, DatetimeIntervalType>();
}

TEST_F(AggregationHandleAvgTest, YearMonthIntervalTypeTest) {
  checkAggregationAvgGeneric<YearMonthIntervalType, YearMonthIntervalType>();
}

TEST_F(AggregationHandleAvgTest, IntTypeValueAccessorTest) {
  checkAggregationAvgGenericValueAccessor<IntType>();
}

TEST_F(AggregationHandleAvgTest, LongTypeValueAccessorTest) {
  checkAggregationAvgGenericValueAccessor<LongType>();
}

TEST_F(AggregationHandleAvgTest, FloatTypeValueAccessorTest) {
  checkAggregationAvgGenericValueAccessor<FloatType>();
}

TEST_F(AggregationHandleAvgTest, DoubleTypeValueAccessorTest) {
  checkAggregationAvgGenericValueAccessor<DoubleType>();
}

TEST_F(AggregationHandleAvgTest, DatetimeIntervalTypeValueAccessorTest) {
  checkAggregationAvgGenericValueAccessor<DatetimeIntervalType,
                                          DatetimeIntervalType>();
}

TEST_F(AggregationHandleAvgTest, YearMonthIntervalTypeValueAccessorTest) {
  checkAggregationAvgGenericValueAccessor<YearMonthIntervalType,
                                          YearMonthIntervalType>();
}

#ifdef QUICKSTEP_DEBUG
TEST_F(AggregationHandleAvgDeathTest, CharTypeTest) {
  const Type &type = CharType::Instance(true, 10);
  EXPECT_DEATH(initializeHandle(type), "");
}

TEST_F(AggregationHandleAvgDeathTest, VarTypeTest) {
  const Type &type = VarCharType::Instance(true, 10);
  EXPECT_DEATH(initializeHandle(type), "");
}

TEST_F(AggregationHandleAvgDeathTest, WrongTypeTest) {
  const Type &int_non_null_type = IntType::Instance(false);
  const Type &long_type = LongType::Instance(true);
  const Type &double_type = DoubleType::Instance(true);
  const Type &float_type = FloatType::Instance(true);
  const Type &char_type = CharType::Instance(true, 10);
  const Type &varchar_type = VarCharType::Instance(true, 10);

  initializeHandle(IntType::Instance(true));
  int int_val = 0;
  std::int64_t long_val = 0;
  double double_val = 0;
  float float_val = 0;

  iterateHandle(aggregation_handle_avg_state_.get(),
                int_non_null_type.makeValue(&int_val));

  EXPECT_DEATH(iterateHandle(aggregation_handle_avg_state_.get(),
                             long_type.makeValue(&long_val)),
               "");
  EXPECT_DEATH(iterateHandle(aggregation_handle_avg_state_.get(),
                             double_type.makeValue(&double_val)),
               "");
  EXPECT_DEATH(iterateHandle(aggregation_handle_avg_state_.get(),
                             float_type.makeValue(&float_val)),
               "");
  EXPECT_DEATH(iterateHandle(aggregation_handle_avg_state_.get(),
                             char_type.makeValue("asdf", 5)),
               "");
  EXPECT_DEATH(iterateHandle(aggregation_handle_avg_state_.get(),
                             varchar_type.makeValue("asdf", 5)),
               "");

  // Test mergeStates() with incorrectly typed handles.
  std::unique_ptr<AggregationHandle> aggregation_handle_avg_double(
      AggregateFunctionFactory::Get(AggregationID::kAvg)
          .createHandle(std::vector<const Type *>(1, &double_type)));
  std::unique_ptr<AggregationState> aggregation_state_avg_merge_double(
      aggregation_handle_avg_double->createInitialState());
  static_cast<const AggregationHandleAvg &>(*aggregation_handle_avg_double)
      .iterateUnaryInl(static_cast<AggregationStateAvg *>(
                           aggregation_state_avg_merge_double.get()),
                       double_type.makeValue(&double_val));
  EXPECT_DEATH(
      aggregation_handle_avg_->mergeStates(*aggregation_state_avg_merge_double,
                                           aggregation_handle_avg_state_.get()),
      "");

  std::unique_ptr<AggregationHandle> aggregation_handle_avg_float(
      AggregateFunctionFactory::Get(AggregationID::kAvg)
          .createHandle(std::vector<const Type *>(1, &float_type)));
  std::unique_ptr<AggregationState> aggregation_state_avg_merge_float(
      aggregation_handle_avg_float->createInitialState());
  static_cast<const AggregationHandleAvg &>(*aggregation_handle_avg_float)
      .iterateUnaryInl(static_cast<AggregationStateAvg *>(
                           aggregation_state_avg_merge_float.get()),
                       float_type.makeValue(&float_val));
  EXPECT_DEATH(
      aggregation_handle_avg_->mergeStates(*aggregation_state_avg_merge_float,
                                           aggregation_handle_avg_state_.get()),
      "");
}
#endif

TEST_F(AggregationHandleAvgTest, canApplyToTypeTest) {
  EXPECT_TRUE(ApplyToTypesTest(kInt));
  EXPECT_TRUE(ApplyToTypesTest(kLong));
  EXPECT_TRUE(ApplyToTypesTest(kFloat));
  EXPECT_TRUE(ApplyToTypesTest(kDouble));
  EXPECT_FALSE(ApplyToTypesTest(kChar));
  EXPECT_FALSE(ApplyToTypesTest(kVarChar));
  EXPECT_FALSE(ApplyToTypesTest(kDatetime));
  EXPECT_TRUE(ApplyToTypesTest(kDatetimeInterval));
  EXPECT_TRUE(ApplyToTypesTest(kYearMonthInterval));
}

TEST_F(AggregationHandleAvgTest, ResultTypeForArgumentTypeTest) {
  EXPECT_TRUE(ResultTypeForArgumentTypeTest(kInt, kDouble));
  EXPECT_TRUE(ResultTypeForArgumentTypeTest(kLong, kDouble));
  EXPECT_TRUE(ResultTypeForArgumentTypeTest(kFloat, kDouble));
  EXPECT_TRUE(ResultTypeForArgumentTypeTest(kDouble, kDouble));
  EXPECT_TRUE(
      ResultTypeForArgumentTypeTest(kDatetimeInterval, kDatetimeInterval));
  EXPECT_TRUE(
      ResultTypeForArgumentTypeTest(kYearMonthInterval, kYearMonthInterval));
}

TEST_F(AggregationHandleAvgTest, GroupByTableMergeTestAvg) {
  const Type &long_non_null_type = LongType::Instance(false);
  initializeHandle(long_non_null_type);
  storage_manager_.reset(new StorageManager("./test_avg_data"));
  std::unique_ptr<AggregationStateHashTableBase> source_hash_table(
      AggregationStateHashTableFactory::CreateResizable(
          HashTableImplType::kSeparateChaining,
          std::vector<const Type *>(1, &long_non_null_type),
          10,
          {aggregation_handle_avg_.get()},
          storage_manager_.get()));
  std::unique_ptr<AggregationStateHashTableBase> destination_hash_table(
      AggregationStateHashTableFactory::CreateResizable(
          HashTableImplType::kSeparateChaining,
          std::vector<const Type *>(1, &long_non_null_type),
          10,
          {aggregation_handle_avg_.get()},
          storage_manager_.get()));

  PackedPayloadHashTable *destination_hash_table_derived =
      static_cast<PackedPayloadHashTable *>(destination_hash_table.get());

  PackedPayloadHashTable *source_hash_table_derived =
      static_cast<PackedPayloadHashTable *>(source_hash_table.get());

  AggregationHandleAvg *aggregation_handle_avg_derived =
      static_cast<AggregationHandleAvg *>(aggregation_handle_avg_.get());
  // We create three keys: first is present in both the hash tables, second key
  // is present only in the source hash table while the third key is present
  // the destination hash table only.
  std::vector<TypedValue> common_key;
  common_key.emplace_back(static_cast<std::int64_t>(0));
  std::vector<TypedValue> exclusive_source_key, exclusive_destination_key;
  exclusive_source_key.emplace_back(static_cast<std::int64_t>(1));
  exclusive_destination_key.emplace_back(static_cast<std::int64_t>(2));

  const std::int64_t common_key_source_avg = 355;
  TypedValue common_key_source_avg_val(common_key_source_avg);

  const std::int64_t common_key_destination_avg = 295;
  TypedValue common_key_destination_avg_val(common_key_destination_avg);

  const std::int64_t exclusive_key_source_avg = 1;
  TypedValue exclusive_key_source_avg_val(exclusive_key_source_avg);

  const std::int64_t exclusive_key_destination_avg = 1;
  TypedValue exclusive_key_destination_avg_val(exclusive_key_destination_avg);

  std::unique_ptr<AggregationStateAvg> common_key_source_state(
      static_cast<AggregationStateAvg *>(
          aggregation_handle_avg_->createInitialState()));
  std::unique_ptr<AggregationStateAvg> common_key_destination_state(
      static_cast<AggregationStateAvg *>(
          aggregation_handle_avg_->createInitialState()));
  std::unique_ptr<AggregationStateAvg> exclusive_key_source_state(
      static_cast<AggregationStateAvg *>(
          aggregation_handle_avg_->createInitialState()));
  std::unique_ptr<AggregationStateAvg> exclusive_key_destination_state(
      static_cast<AggregationStateAvg *>(
          aggregation_handle_avg_->createInitialState()));

  // Create avg value states for keys.
  aggregation_handle_avg_derived->iterateUnaryInl(common_key_source_state.get(),
                                                  common_key_source_avg_val);

  aggregation_handle_avg_derived->iterateUnaryInl(
      common_key_destination_state.get(), common_key_destination_avg_val);

  aggregation_handle_avg_derived->iterateUnaryInl(
      exclusive_key_destination_state.get(), exclusive_key_destination_avg_val);

  aggregation_handle_avg_derived->iterateUnaryInl(
      exclusive_key_source_state.get(), exclusive_key_source_avg_val);

  // Add the key-state pairs to the hash tables.
  unsigned char buffer[100];
  buffer[0] = '\0';
  memcpy(buffer + 1,
         common_key_source_state.get()->getPayloadAddress(),
         aggregation_handle_avg_.get()->getPayloadSize());
  source_hash_table_derived->upsertCompositeKey(common_key, buffer);

  memcpy(buffer + 1,
         common_key_destination_state.get()->getPayloadAddress(),
         aggregation_handle_avg_.get()->getPayloadSize());
  destination_hash_table_derived->upsertCompositeKey(common_key, buffer);

  memcpy(buffer + 1,
         exclusive_key_source_state.get()->getPayloadAddress(),
         aggregation_handle_avg_.get()->getPayloadSize());
  source_hash_table_derived->upsertCompositeKey(exclusive_source_key, buffer);

  memcpy(buffer + 1,
         exclusive_key_destination_state.get()->getPayloadAddress(),
         aggregation_handle_avg_.get()->getPayloadSize());
  destination_hash_table_derived->upsertCompositeKey(exclusive_destination_key,
                                                      buffer);

  EXPECT_EQ(2u, destination_hash_table_derived->numEntries());
  EXPECT_EQ(2u, source_hash_table_derived->numEntries());

  HashTableMerger merger(destination_hash_table_derived);
  source_hash_table_derived->forEachCompositeKey(&merger);

  EXPECT_EQ(3u, destination_hash_table_derived->numEntries());

  CheckAvgValue<double>(
      (common_key_destination_avg_val.getLiteral<std::int64_t>() +
       common_key_source_avg_val.getLiteral<std::int64_t>()) /
          static_cast<double>(2),
      aggregation_handle_avg_derived->finalizeHashTableEntry(
          destination_hash_table_derived->getSingleCompositeKey(common_key) +
          1));
  CheckAvgValue<double>(
      exclusive_key_destination_avg_val.getLiteral<std::int64_t>(),
      aggregation_handle_avg_derived->finalizeHashTableEntry(
          destination_hash_table_derived->getSingleCompositeKey(
              exclusive_destination_key) + 1));
  CheckAvgValue<double>(
      exclusive_key_source_avg_val.getLiteral<std::int64_t>(),
      aggregation_handle_avg_derived->finalizeHashTableEntry(
          source_hash_table_derived->getSingleCompositeKey(
              exclusive_source_key) + 1));
}

}  // namespace quickstep