// 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.

// This file is copied from

// https://github.com/ClickHouse/ClickHouse/blob/master/src/Functions/array/arraySort.cpp

// and modified by Doris

#pragma once

#include <fmt/format.h>

#include <glog/logging.h>

#include <stddef.h>

#include <memory>

#include <ostream>

#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_array.h"

#include "core/data_type/data_type.h"

#include "core/types.h"

#include "exprs/function/function.h"

namespace doris {

class FunctionContext;

} // namespace doris

namespace doris {

template <typename Name, bool Positive>

class FunctionArraySort : public IFunction {

public:

static constexpr auto name = Name::name;

static FunctionPtr create() { return std::make_shared<FunctionArraySort<Name, Positive>>(); }

/// Get function name.

String get_name() const override { return name; }

bool is_variadic() const override { return false; }

size_t get_number_of_arguments() const override { return 1; }

DataTypePtr get_return_type_impl(const DataTypes& arguments) const override {

DCHECK(arguments[0]->get_primitive_type() == TYPE_ARRAY)

<< "first argument for function: " << name << " should be DataTypeArray"

<< " and arguments[0] is " << arguments[0]->get_name();

return arguments[0];

}

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

uint32_t result, size_t input_rows_count) const override {

ColumnPtr src_column =

block.get_by_position(arguments[0]).column->convert_to_full_column_if_const();

const auto& src_column_array = check_and_get_column<ColumnArray>(*src_column);

if (!src_column_array) {

return Status::RuntimeError(

fmt::format("unsupported types for function {}({})", get_name(),

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

}

auto dest_column_ptr = _execute(*src_column_array);

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

return Status::OK();

}

private:

ColumnPtr _execute(const ColumnArray& src_column_array) const {

const auto& src_offsets = src_column_array.get_offsets();

const auto& src_nested_column = src_column_array.get_data();

size_t size = src_offsets.size();

size_t nested_size = src_nested_column.size();

IColumn::Permutation permutation(nested_size);

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

permutation[i] = i;

}

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

auto current_offset = src_offsets[i - 1];

auto next_offset = src_offsets[i];

std::sort(&permutation[current_offset], &permutation[next_offset],

Less(src_nested_column));

}

return ColumnArray::create(src_column_array.get_data().permute(permutation, 0),

src_column_array.get_offsets_ptr());

}

struct Less {

const IColumn& column;

explicit Less(const IColumn& column_) : column(column_) {}

bool operator()(size_t lhs, size_t rhs) const {

if (Positive) {

return column.compare_at(lhs, rhs, column, -1) < 0;

} else {

return column.compare_at(lhs, rhs, column, -1) > 0;

}

}

};

};

} // namespace doris