// 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 "exprs/table_function/vexplode_json_object.h"

#include <glog/logging.h>

#include <ostream>

#include "common/status.h"

#include "core/block/block.h"

#include "core/block/column_with_type_and_name.h"

#include "core/column/column.h"

#include "core/column/column_struct.h"

#include "core/string_ref.h"

#include "exprs/vexpr.h"

#include "exprs/vexpr_context.h"

#include "util/jsonb_document.h"

#include "util/jsonb_writer.h"

namespace doris {

VExplodeJsonObjectTableFunction::VExplodeJsonObjectTableFunction() {

_fn_name = "vexplode_json_object";

}

Status VExplodeJsonObjectTableFunction::process_init(Block* block, RuntimeState* state) {

CHECK(_expr_context->root()->children().size() == 1)

<< "VExplodeJsonObjectTableFunction only support 1 child but has "

<< _expr_context->root()->children().size();

RETURN_IF_ERROR(_expr_context->root()->children()[0]->execute_column(

_expr_context.get(), block, nullptr, block->rows(), _json_object_column));

return Status::OK();

}

void VExplodeJsonObjectTableFunction::process_row(size_t row_idx) {

TableFunction::process_row(row_idx);

StringRef text = _json_object_column->get_data_at(row_idx);

if (text.data != nullptr) {

const JsonbDocument* doc = nullptr;

auto st = JsonbDocument::checkAndCreateDocument(text.data, text.size, &doc);

if (!st.ok() || !doc || !doc->getValue()) [[unlikely]] {

// error jsonb, put null into output, cur_size = 0 , we will insert_default

return;

}

// value is NOT necessary to be deleted since JsonbValue will not allocate memory

const JsonbValue* value = doc->getValue();

auto writer = std::make_unique<JsonbWriter>();

if (value->isObject()) {

_cur_size = value->numElements();

const auto* obj = value->unpack<ObjectVal>();

_object_pairs.first =

ColumnNullable::create(ColumnString::create(), ColumnUInt8::create());

_object_pairs.second =

ColumnNullable::create(ColumnString::create(), ColumnUInt8::create());

_object_pairs.first->reserve(_cur_size);

_object_pairs.second->reserve(_cur_size);

for (const auto& it : *obj) {

_object_pairs.first->insert_data(it.getKeyStr(), it.klen());

writer->reset();

writer->writeValue(it.value());

if (it.value()->isNull()) {

_object_pairs.second->insert_default();

} else {

const std::string_view& jsonb_value = std::string_view(

writer->getOutput()->getBuffer(), writer->getOutput()->getSize());

_object_pairs.second->insert_data(jsonb_value.data(), jsonb_value.size());

}

}

}

// we do not support other json type except object

}

}

void VExplodeJsonObjectTableFunction::process_close() {

_json_object_column = nullptr;

_object_pairs.first = nullptr;

_object_pairs.second = nullptr;

}

void VExplodeJsonObjectTableFunction::get_same_many_values(MutableColumnPtr& column, int length) {

// if current is empty map row, also append a default value

if (current_empty()) {

column->insert_many_defaults(length);

return;

}

ColumnStruct* ret = nullptr;

// this _is_nullable is whole output column's nullable

if (_is_nullable) {

// make map kv value into struct

ret = assert_cast<ColumnStruct*>(

assert_cast<ColumnNullable*>(column.get())->get_nested_column_ptr().get());

assert_cast<ColumnNullable*>(column.get())

->get_null_map_column_ptr()

->insert_many_defaults(length);

} else if (is_column<ColumnStruct>(column.get())) {

ret = assert_cast<ColumnStruct*>(column.get());

} else {

throw Exception(ErrorCode::INTERNAL_ERROR,

"only support expand json object int to struct(kv pair), but given: ",

column->get_name());

}

if (!ret || ret->tuple_size() != 2) {

throw Exception(ErrorCode::INTERNAL_ERROR,

"only support expand json object int to kv pair column, but given: ",

ret->tuple_size());

}

ret->get_column(0).insert_many_from(*_object_pairs.first, _cur_offset, length);

ret->get_column(1).insert_many_from(*_object_pairs.second, _cur_offset, length);

}

int VExplodeJsonObjectTableFunction::get_value(MutableColumnPtr& column, int max_step) {

max_step = std::min(max_step, (int)(_cur_size - _cur_offset));

if (current_empty()) {

column->insert_default();

max_step = 1;

} else {

ColumnStruct* struct_column = nullptr;

if (_is_nullable) {

auto* nullable_column = assert_cast<ColumnNullable*>(column.get());

struct_column =

assert_cast<ColumnStruct*>(nullable_column->get_nested_column_ptr().get());

auto* nullmap_column = nullable_column->get_null_map_column_ptr().get();

// here nullmap_column insert max_step many defaults as if MAP[row_idx] is NULL

// will be not update value, _cur_size = 0, means current_empty;

// so here could insert directly

nullmap_column->insert_many_defaults(max_step);

} else {

struct_column = assert_cast<ColumnStruct*>(column.get());

}

if (!struct_column || struct_column->tuple_size() != 2) {

throw Exception(ErrorCode::INTERNAL_ERROR,

"only support expand json object int to kv pair column, but given: ",

struct_column->tuple_size());

}

struct_column->get_column(0).insert_range_from(*_object_pairs.first, _cur_offset, max_step);

struct_column->get_column(1).insert_range_from(*_object_pairs.second, _cur_offset,

max_step);

}

forward(max_step);

return max_step;

}

} // namespace doris