// 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 <algorithm>

#include <cstddef>

#include <cstdint>

#include <memory>

#include <utility>

#include <vector>

#include "common/cast_set.h"

#include "common/status.h"

#include "core/block/block.h"

#include "core/block/column_numbers.h"

#include "core/block/column_with_type_and_name.h"

#include "core/column/column.h"

#include "core/column/column_complex.h"

#include "core/column/column_nullable.h"

#include "core/column/column_string.h"

#include "core/column/column_vector.h"

#include "core/data_type/data_type.h"

#include "core/data_type/data_type_hll.h"

#include "core/data_type/data_type_number.h"

#include "core/data_type/data_type_string.h"

#include "core/types.h"

#include "core/value/hll.h"

#include "exprs/function/function.h"

#include "exprs/function/function_always_not_nullable.h"

#include "exprs/function/function_const.h"

#include "exprs/function/function_totype.h"

#include "exprs/function/simple_function_factory.h"

#include "util/hash_util.hpp"

#include "util/url_coding.h"

namespace doris {

struct HLLCardinality {

    static constexpr auto name = "hll_cardinality";

    using ReturnType = DataTypeInt64;

    static void vector(const std::vector<HyperLogLog>& data, MutableColumnPtr& col_res) {

        typename ColumnInt64::Container& res =

                reinterpret_cast<ColumnInt64*>(col_res.get())->get_data();

        auto size = res.size();

        for (int i = 0; i < size; ++i) {

            res[i] = data[i].estimate_cardinality();

        }

    }

    static void vector_nullable(const std::vector<HyperLogLog>& data, const NullMap& nullmap,

                                MutableColumnPtr& col_res) {

        typename ColumnInt64::Container& res =

                reinterpret_cast<ColumnInt64*>(col_res.get())->get_data();

        auto size = res.size();

        for (int i = 0; i < size; ++i) {

            if (nullmap[i]) {

                res[i] = 0;

            } else {

                res[i] = data[i].estimate_cardinality();

            }

        }

    }

};

template <typename Function>

class FunctionHLL : public IFunction {

public:

    static constexpr auto name = Function::name;

    static FunctionPtr create() { return std::make_shared<FunctionHLL>(); }

    String get_name() const override { return Function::name; }

    size_t get_number_of_arguments() const override { return 1; }

    DataTypePtr get_return_type_impl(const DataTypes& arguments) const override {

        return std::make_shared<typename Function::ReturnType>();

    }

    bool use_default_implementation_for_nulls() const override { return false; }

    Status execute_impl(FunctionContext* context, Block& block, const ColumnNumbers& arguments,

                        uint32_t result, size_t input_rows_count) const override {

        auto column = block.get_by_position(arguments[0]).column;

        MutableColumnPtr column_result = get_return_type_impl({})->create_column();

        column_result->resize(input_rows_count);

        if (const ColumnNullable* col_nullable =

                    check_and_get_column<ColumnNullable>(column.get())) {

            const ColumnHLL* col =

                    check_and_get_column<ColumnHLL>(col_nullable->get_nested_column_ptr().get());

            const ColumnUInt8* col_nullmap = check_and_get_column<ColumnUInt8>(

                    col_nullable->get_null_map_column_ptr().get());

            if (col != nullptr && col_nullmap != nullptr) {

                Function::vector_nullable(col->get_data(), col_nullmap->get_data(), column_result);

                block.replace_by_position(result, std::move(column_result));

                return Status::OK();

            }

        } else if (const ColumnHLL* col = check_and_get_column<ColumnHLL>(column.get())) {

            Function::vector(col->get_data(), column_result);

            block.replace_by_position(result, std::move(column_result));

            return Status::OK();

        } else {

            return Status::RuntimeError("Illegal column {} of argument of function {}",

                                        block.get_by_position(arguments[0]).column->get_name(),

                                        get_name());

        }

        block.replace_by_position(result, std::move(column_result));

        return Status::OK();

    }

};

struct HLLEmptyImpl {

    static constexpr auto name = "hll_empty";

    using ReturnColVec = ColumnHLL;

    static auto get_return_type() { return std::make_shared<DataTypeHLL>(); }

    static HyperLogLog init_value() { return HyperLogLog {}; }

};

class FunctionHllFromBase64 : public IFunction {

public:

    static constexpr auto name = "hll_from_base64";

    String get_name() const override { return name; }

    static FunctionPtr create() { return std::make_shared<FunctionHllFromBase64>(); }

    DataTypePtr get_return_type_impl(const DataTypes& arguments) const override {

        return make_nullable(std::make_shared<DataTypeHLL>());

    }

    size_t get_number_of_arguments() const override { return 1; }

    Status execute_impl(FunctionContext* context, Block& block, const ColumnNumbers& arguments,

                        uint32_t result, size_t input_rows_count) const override {

        auto res_null_map = ColumnUInt8::create(input_rows_count, 0);

        auto res_data_column = ColumnHLL::create();

        auto& null_map = res_null_map->get_data();

        auto& res = res_data_column->get_data();

        auto& argument_column = block.get_by_position(arguments[0]).column;

        const auto& str_column = static_cast<const ColumnString&>(*argument_column);

        const ColumnString::Chars& data = str_column.get_chars();

        const ColumnString::Offsets& offsets = str_column.get_offsets();

        res.reserve(input_rows_count);

        std::string decode_buff;

        int64_t last_decode_buff_len = 0;

        int64_t curr_decode_buff_len = 0;

        for (size_t i = 0; i < input_rows_count; ++i) {

            const char* src_str = reinterpret_cast<const char*>(&data[offsets[i - 1]]);

            int64_t src_size = offsets[i] - offsets[i - 1];

            // Base64 encoding has a characteristic where every 4 characters represent 3 bytes of data.

            // Here, we check if the length of the input string is a multiple of 4 to ensure it's a valid base64 encoded string.

            if (0 != src_size % 4) {

                res.emplace_back();

                null_map[i] = 1;

                continue;

            }

            // Allocate sufficient space for the decoded data.

            // The number 3 here represents the number of bytes in the decoded data for each group of 4 base64 characters.

            // We set the size of the decoding buffer to be 'src_size + 3' to ensure there is enough space to store the decoded data.

            curr_decode_buff_len = src_size + 3;

            if (curr_decode_buff_len > last_decode_buff_len) {

                decode_buff.resize(curr_decode_buff_len);

                last_decode_buff_len = curr_decode_buff_len;

            }

            auto outlen = base64_decode(src_str, src_size, decode_buff.data());

            if (outlen < 0) {

                res.emplace_back();

                null_map[i] = 1;

            } else {

                doris::Slice decoded_slice(decode_buff.data(), outlen);

                doris::HyperLogLog hll;

                if (!hll.deserialize(decoded_slice)) {

                    return Status::RuntimeError(

                            fmt::format("hll_from_base64 decode failed: base64: {}",

                                        StringRef(src_str, src_size).to_string()));

                } else {

                    res.emplace_back(std::move(hll));

                }

            }

        }

        block.get_by_position(result).column =

                ColumnNullable::create(std::move(res_data_column), std::move(res_null_map));

        return Status::OK();

    }

};

struct HLLHash {

    static constexpr auto name = "hll_hash";

    using ReturnType = DataTypeHLL;

    template <typename ColumnType>

    static void vector(const ColumnType* col, MutableColumnPtr& col_res) {

        if constexpr (std::is_same_v<ColumnType, ColumnString>) {

            const ColumnString::Chars& data = col->get_chars();

            const ColumnString::Offsets& offsets = col->get_offsets();

            auto* res_column = reinterpret_cast<ColumnHLL*>(col_res.get());

            auto& res_data = res_column->get_data();

            size_t size = offsets.size();

            for (size_t i = 0; i < size; ++i) {

                const char* raw_str = reinterpret_cast<const char*>(&data[offsets[i - 1]]);

                size_t str_size = offsets[i] - offsets[i - 1];

                uint64_t hash_value =

                        HashUtil::murmur_hash64A(raw_str, str_size, HashUtil::MURMUR_SEED);

                res_data[i].update(hash_value);

            }

        }

    }

Unexecuted instantiation: _ZN5doris7HLLHash6vectorINS_9ColumnStrIjEEEEvPKT_RNS_3COWINS_7IColumnEE11mutable_ptrIS8_EE

Unexecuted instantiation: _ZN5doris7HLLHash6vectorINS_12ColumnVectorILNS_13PrimitiveTypeE6EEEEEvPKT_RNS_3COWINS_7IColumnEE11mutable_ptrIS9_EE

    template <typename ColumnType>

    static void vector_nullable(const ColumnType* col, const NullMap& nullmap,

                                MutableColumnPtr& col_res) {

        if constexpr (std::is_same_v<ColumnType, ColumnString>) {

            const ColumnString::Chars& data = col->get_chars();

            const ColumnString::Offsets& offsets = col->get_offsets();

            auto* res_column = reinterpret_cast<ColumnHLL*>(col_res.get());

            auto& res_data = res_column->get_data();

            size_t size = offsets.size();

            for (size_t i = 0; i < size; ++i) {

                if (nullmap[i]) {

                    continue;

                } else {

                    const char* raw_str = reinterpret_cast<const char*>(&data[offsets[i - 1]]);

                    size_t str_size = offsets[i] - offsets[i - 1];

                    uint64_t hash_value =

                            HashUtil::murmur_hash64A(raw_str, str_size, HashUtil::MURMUR_SEED);

                    res_data[i].update(hash_value);

                }

            }

        }

    }

Unexecuted instantiation: _ZN5doris7HLLHash15vector_nullableINS_9ColumnStrIjEEEEvPKT_RKNS_8PODArrayIhLm4096ENS_9AllocatorILb0ELb0ELb0ENS_22DefaultMemoryAllocatorELb1EEELm16ELm15EEERNS_3COWINS_7IColumnEE11mutable_ptrISF_EE

Unexecuted instantiation: _ZN5doris7HLLHash15vector_nullableINS_12ColumnVectorILNS_13PrimitiveTypeE6EEEEEvPKT_RKNS_8PODArrayIhLm4096ENS_9AllocatorILb0ELb0ELb0ENS_22DefaultMemoryAllocatorELb1EEELm16ELm15EEERNS_3COWINS_7IColumnEE11mutable_ptrISG_EE

};

struct NameHllToBase64 {

    static constexpr auto name = "hll_to_base64";

};

struct HllToBase64 {

    using ReturnType = DataTypeString;

    static constexpr auto PrimitiveTypeImpl = PrimitiveType::TYPE_HLL;

    using Type = DataTypeHLL::FieldType;

    using ReturnColumnType = ColumnString;

    using Chars = ColumnString::Chars;

    using Offsets = ColumnString::Offsets;

    static Status vector(const std::vector<HyperLogLog>& data, Chars& chars, Offsets& offsets) {

        size_t size = data.size();

        offsets.resize(size);

        size_t output_char_size = 0;

        for (size_t i = 0; i < size; ++i) {

            auto& hll_val = data[i];

            auto ser_size = hll_val.max_serialized_size();

            output_char_size += (int)(4.0 * ceil((double)ser_size / 3.0));

        }

        ColumnString::check_chars_length(output_char_size, size);

        chars.resize(output_char_size);

        auto* chars_data = chars.data();

        size_t cur_ser_size = 0;

        size_t last_ser_size = 0;

        std::string ser_buff;

        size_t encoded_offset = 0;

        for (size_t i = 0; i < size; ++i) {

            auto& hll_val = data[i];

            cur_ser_size = hll_val.max_serialized_size();

            if (cur_ser_size > last_ser_size) {

                last_ser_size = cur_ser_size;

                ser_buff.resize(cur_ser_size);

            }

            size_t real_size = hll_val.serialize(reinterpret_cast<uint8_t*>(ser_buff.data()));

            auto outlen = base64_encode((const unsigned char*)ser_buff.data(), real_size,

                                        chars_data + encoded_offset);

            DCHECK(outlen > 0);

            encoded_offset += outlen;

            offsets[i] = cast_set<uint32_t>(encoded_offset);

        }

        return Status::OK();

    }

};

using FunctionHLLCardinality = FunctionHLL<HLLCardinality>;

using FunctionHLLEmpty = FunctionConst<HLLEmptyImpl, false>;

using FunctionHLLHash = FunctionAlwaysNotNullable<HLLHash>;

using FunctionHllToBase64 = FunctionUnaryToType<HllToBase64, NameHllToBase64>;

void register_function_hll(SimpleFunctionFactory& factory) {

    factory.register_function<FunctionHLLCardinality>();

    factory.register_function<FunctionHLLEmpty>();

    factory.register_function<FunctionHllFromBase64>();

    factory.register_function<FunctionHLLHash>();

    factory.register_function<FunctionHllToBase64>();

}

} // namespace doris