// 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.

#pragma once

#include <glog/logging.h>

#include <parallel_hashmap/phmap.h>

#include "core/assert_cast.h"

#include "core/column/column_decimal.h"

#include "core/column/column_map.h"

#include "core/column/column_string.h"

#include "core/data_type/data_type_map.h"

#include "core/field.h"

#include "exprs/aggregate/aggregate_function.h"

#include "exprs/aggregate/aggregate_function_simple_factory.h"

namespace doris {

struct AggregateFunctionMapAggDataV2 {

    using Map = phmap::flat_hash_map<Field, int64_t>;

    AggregateFunctionMapAggDataV2() {

        throw Exception(Status::FatalError("__builtin_unreachable"));

    }

    AggregateFunctionMapAggDataV2(const DataTypes& argument_types, const int be_exec_version)

            : _be_version(be_exec_version) {

        _key_type = make_nullable(argument_types[0]);

        _value_type = make_nullable(argument_types[1]);

        _key_column = _key_type->create_column();

        _value_column = _value_type->create_column();

    }

    void reset() {

        _map.clear();

        _key_column->clear();

        _value_column->clear();

    }

    void add_single(const Field& key, const Field& value) {

        if (UNLIKELY(_map.find(key) != _map.end())) {

            return;

        }

        _map.emplace(key, _key_column->size());

        _key_column->insert(key);

        _value_column->insert(value);

    }

    void add(const Field& key_, const Field& value) {

        DCHECK(!key_.is_null());

        auto key_array = key_.get<TYPE_ARRAY>();

        auto value_array = value.get<TYPE_ARRAY>();

        const auto count = key_array.size();

        DCHECK_EQ(count, value_array.size());

        for (size_t i = 0; i != count; ++i) {

            const auto& key = key_array[i];

            if (UNLIKELY(_map.find(key) != _map.end())) {

                continue;

            }

            _map.emplace(key, _key_column->size());

            _key_column->insert(key);

            _value_column->insert(value_array[i]);

        }

    }

    void merge(const AggregateFunctionMapAggDataV2& other) {

        const size_t num_rows = other._key_column->size();

        if (num_rows == 0) {

            return;

        }

        auto& other_key_column_nullable = assert_cast<ColumnNullable&>(*other._key_column);

        for (size_t i = 0; i != num_rows; ++i) {

            const auto& key = other_key_column_nullable[i];

            if (_map.find(key) != _map.cend()) {

                continue;

            }

            _map.emplace(key, _key_column->size());

            _key_column->insert(key);

            _value_column->insert((*other._value_column)[i]);

        }

    }

    void insert_result_into(IColumn& to) const {

        auto& dst = assert_cast<ColumnMap&>(to);

        size_t num_rows = _key_column->size();

        auto& offsets = dst.get_offsets();

        auto& dst_key_column = assert_cast<ColumnNullable&>(dst.get_keys());

        dst_key_column.insert_range_from(*_key_column, 0, num_rows);

        dst.get_values().insert_range_from(*_value_column, 0, num_rows);

        if (offsets.empty()) {

            offsets.push_back(num_rows);

        } else {

            offsets.push_back(offsets.back() + num_rows);

        }

    }

    void write(BufferWritable& buf) const {

        auto serialized_bytes =

                _key_type->get_uncompressed_serialized_bytes(*_key_column, _be_version);

        std::string serialized_buffer;

        serialized_buffer.resize(serialized_bytes);

        auto* buf_ptr = _key_type->serialize(*_key_column, serialized_buffer.data(), _be_version);

        int64_t written_bytes = buf_ptr - serialized_buffer.data();

        DCHECK_LE(written_bytes, serialized_bytes);

        serialized_buffer.resize(serialized_bytes);

        buf.write_binary(serialized_buffer);

        serialized_bytes =

                _value_type->get_uncompressed_serialized_bytes(*_value_column, _be_version);

        serialized_buffer.resize(serialized_bytes);

        buf_ptr = _value_type->serialize(*_value_column, serialized_buffer.data(), _be_version);

        written_bytes = buf_ptr - serialized_buffer.data();

        DCHECK_LE(written_bytes, serialized_bytes);

        serialized_buffer.resize(written_bytes);

        buf.write_binary(serialized_buffer);

    }

    void read(BufferReadable& buf) {

        std::string deserialized_buffer;

        buf.read_binary(deserialized_buffer);

        const auto* ptr =

                _key_type->deserialize(deserialized_buffer.data(), &_key_column, _be_version);

        auto read_bytes = ptr - deserialized_buffer.data();

        DCHECK_EQ(read_bytes, deserialized_buffer.size());

        buf.read_binary(deserialized_buffer);

        ptr = _value_type->deserialize(deserialized_buffer.data(), &_value_column, _be_version);

        read_bytes = ptr - deserialized_buffer.data();

        DCHECK_EQ(read_bytes, deserialized_buffer.size());

    }

private:

    Map _map;

    Arena _arena;

    IColumn::MutablePtr _key_column;

    IColumn::MutablePtr _value_column;

    DataTypePtr _key_type;

    DataTypePtr _value_type;

    int _be_version;

};

template <typename Data>

class AggregateFunctionMapAggV2 final

        : public IAggregateFunctionDataHelper<Data, AggregateFunctionMapAggV2<Data>>,

          MultiExpression,

          NotNullableAggregateFunction {

public:

    AggregateFunctionMapAggV2() = default;

    AggregateFunctionMapAggV2(const DataTypes& argument_types_)

            : IAggregateFunctionDataHelper<Data, AggregateFunctionMapAggV2<Data>>(argument_types_) {

    }

    using IAggregateFunctionDataHelper<Data, AggregateFunctionMapAggV2<Data>>::version;

    std::string get_name() const override { return "map_agg_v2"; }

    DataTypePtr get_return_type() const override {

        /// keys and values column of `ColumnMap` are always nullable.

        return std::make_shared<DataTypeMap>(make_nullable(argument_types[0]),

                                             make_nullable(argument_types[1]));

    }

    void add(AggregateDataPtr __restrict place, const IColumn** columns, ssize_t row_num,

             Arena&) const override {

        Field key, value;

        columns[0]->get(row_num, key);

        columns[1]->get(row_num, value);

        this->data(place).add_single(key, value);

    }

    void create(AggregateDataPtr __restrict place) const override {

        new (place) Data(argument_types, version);

    }

    void reset(AggregateDataPtr place) const override { this->data(place).reset(); }

    void merge(AggregateDataPtr __restrict place, ConstAggregateDataPtr rhs,

               Arena&) const override {

        this->data(place).merge(this->data(rhs));

    }

    void serialize(ConstAggregateDataPtr __restrict place, BufferWritable& buf) const override {

        this->data(place).write(buf);

    }

    void deserialize(AggregateDataPtr __restrict place, BufferReadable& buf,

                     Arena&) const override {

        this->data(place).read(buf);

    }

    void streaming_agg_serialize_to_column(const IColumn** columns, MutableColumnPtr& dst,

                                           const size_t num_rows, Arena&) const override {

        auto& col = assert_cast<ColumnMap&>(*dst);

        for (size_t i = 0; i != num_rows; ++i) {

            Field key, value;

            columns[0]->get(i, key);

            columns[1]->get(i, value);

            col.insert(Field::create_field<TYPE_MAP>(

                    Map {Field::create_field<TYPE_ARRAY>(Array {key}),

                         Field::create_field<TYPE_ARRAY>(Array {value})}));

        }

    }

    void serialize_to_column(const std::vector<AggregateDataPtr>& places, size_t offset,

                             MutableColumnPtr& dst, const size_t num_rows) const override {

        for (size_t i = 0; i != num_rows; ++i) {

            Data& data_ = this->data(places[i] + offset);

            data_.insert_result_into(*dst);

        }

    }

    void deserialize_and_merge_from_column_range(AggregateDataPtr __restrict place,

                                                 const IColumn& column, size_t begin, size_t end,

                                                 Arena&) const override {

        DCHECK(end <= column.size() && begin <= end)

                << ", begin:" << begin << ", end:" << end << ", column.size():" << column.size();

        const auto& col = assert_cast<const ColumnMap&>(column);

        for (size_t i = begin; i <= end; ++i) {

            auto map = col[i].get<TYPE_MAP>();

            this->data(place).add(map[0], map[1]);

        }

    }

    void deserialize_and_merge_vec(const AggregateDataPtr* places, size_t offset,

                                   AggregateDataPtr rhs, const IColumn* column, Arena&,

                                   const size_t num_rows) const override {

        const auto& col = assert_cast<const ColumnMap&>(*column);

        for (size_t i = 0; i != num_rows; ++i) {

            auto map = col[i].get<TYPE_MAP>();

            this->data(places[i] + offset).add(map[0], map[1]);

        }

    }

    void deserialize_and_merge_vec_selected(const AggregateDataPtr* places, size_t offset,

                                            AggregateDataPtr rhs, const IColumn* column, Arena&,

                                            const size_t num_rows) const override {

        const auto& col = assert_cast<const ColumnMap&>(*column);

        for (size_t i = 0; i != num_rows; ++i) {

            if (places[i]) {

                auto map = col[i].get<TYPE_MAP>();

                this->data(places[i] + offset).add(map[0], map[1]);

            }

        }

    }

    void serialize_without_key_to_column(ConstAggregateDataPtr __restrict place,

                                         IColumn& to) const override {

        this->data(place).insert_result_into(to);

    }

    void insert_result_into(ConstAggregateDataPtr __restrict place, IColumn& to) const override {

        this->data(place).insert_result_into(to);

    }

    [[nodiscard]] MutableColumnPtr create_serialize_column() const override {

        return get_return_type()->create_column();

    }

    [[nodiscard]] DataTypePtr get_serialized_type() const override { return get_return_type(); }

protected:

    using IAggregateFunction::argument_types;

};

} // namespace doris