// 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 "core/column/column_array.h"

#include "core/column/column_nullable.h"

#include "core/data_type/data_type_array.h"

#include "core/data_type/data_type_number.h"

#include "exprs/function/function.h"

#include "exprs/function/function_helpers.h"

#include "exprs/function/simple_function_factory.h"

namespace doris {

// array_count([0, 1, 1, 1, 0, 0]) -> [3]

class FunctionArrayCount : public IFunction {

public:

static constexpr auto name = "array_count";

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

String get_name() const override { return name; }

bool is_variadic() const override { return false; }

size_t get_number_of_arguments() const override { return 1; }

bool use_default_implementation_for_nulls() const override { return false; }

ColumnNumbers get_arguments_that_are_always_constant() const override { return {1}; }

DataTypePtr get_return_type_impl(const DataTypes& arguments) const override {

return std::make_shared<DataTypeInt64>();

}

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

uint32_t result, size_t input_rows_count) const override {

const auto& [src_column, src_const] =

unpack_if_const(block.get_by_position(arguments[0]).column);

const ColumnArray* array_column = nullptr;

const UInt8* array_null_map = nullptr;

if (const auto* nullable_array = check_and_get_column<ColumnNullable>(src_column.get())) {

array_column = assert_cast<const ColumnArray*>(&nullable_array->get_nested_column());

array_null_map = nullable_array->get_null_map_column().get_data().data();

} else {

array_column = assert_cast<const ColumnArray*>(src_column.get());

}

if (!array_column) {

return Status::RuntimeError("unsupported types for function {}({})", get_name(),

block.get_by_position(arguments[0]).type->get_name());

}

const auto& offsets = array_column->get_offsets();

ColumnPtr nested_column = nullptr;

const UInt8* nested_null_map = nullptr;

if (is_column_nullable(array_column->get_data())) {

const auto& nested_null_column =

assert_cast<const ColumnNullable&>(array_column->get_data());

nested_null_map = nested_null_column.get_null_map_column().get_data().data();

nested_column = nested_null_column.get_nested_column_ptr();

} else {

nested_column = array_column->get_data_ptr();

}

const auto& nested_data = assert_cast<const ColumnUInt8&>(*nested_column).get_data();

auto dst_column = ColumnInt64::create(offsets.size());

auto& dst_data = dst_column->get_data();

for (size_t row = 0; row < offsets.size(); ++row) {

Int64 res = 0;

if (array_null_map && array_null_map[row]) {

dst_data[row] = res;

continue;

}

size_t off = offsets[row - 1];

size_t len = offsets[row] - off;

for (size_t pos = 0; pos < len; ++pos) {

if (nested_null_map && nested_null_map[pos + off]) {

continue;

}

if (nested_data[pos + off] != 0) {

++res;

}

}

dst_data[row] = res;

}

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

return Status::OK();

}

};

void register_function_array_count(SimpleFunctionFactory& factory) {

factory.register_function<FunctionArrayCount>();

}

} // namespace doris