/**
 * Copyright (c) 2021 OceanBase
 * OceanBase CE is licensed under Mulan PubL v2.
 * You can use this software according to the terms and conditions of the Mulan PubL v2.
 * You may obtain a copy of Mulan PubL v2 at:
 *          http://license.coscl.org.cn/MulanPubL-2.0
 * THIS SOFTWARE IS PROVIDED ON AN "AS IS" BASIS, WITHOUT WARRANTIES OF ANY KIND,
 * EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO NON-INFRINGEMENT,
 * MERCHANTABILITY OR FIT FOR A PARTICULAR PURPOSE.
 * See the Mulan PubL v2 for more details.
 */

#define USING_LOG_PREFIX SQL_ENG

#include "ob_values_op.h"
#include "sql/engine/ob_exec_context.h"

namespace oceanbase {
namespace sql {
using namespace common;

ObValuesSpec::ObValuesSpec(ObIAllocator& alloc, const ObPhyOperatorType type) : ObOpSpec(alloc, type), row_store_(alloc)
{}

OB_SERIALIZE_MEMBER((ObValuesSpec, ObOpSpec), row_store_);

ObValuesOp::ObValuesOp(ObExecContext& exec_ctx, const ObOpSpec& spec, ObOpInput* input)
    : ObOperator(exec_ctx, spec, input)
{}

int ObValuesOp::inner_open()
{
  int ret = OB_SUCCESS;
  row_store_it_ = MY_SPEC.row_store_.begin();
  ObObj* cells = static_cast<ObObj*>(ctx_.get_allocator().alloc(sizeof(ObObj) * MY_SPEC.output_.count()));
  if (OB_ISNULL(cells)) {
    ret = OB_ALLOCATE_MEMORY_FAILED;
    LOG_WARN("alloc memory failed", K(ret));
  } else {
    for (int64_t i = 0; i < MY_SPEC.output_.count(); i++) {
      new (&cells[i]) ObObj();
    }
    cur_row_.cells_ = cells;
    cur_row_.count_ = MY_SPEC.output_.count();
  }
  return ret;
}

int ObValuesOp::rescan()
{
  row_store_it_ = MY_SPEC.row_store_.begin();
  return ObOperator::rescan();
}

int ObValuesOp::inner_get_next_row()
{
  int ret = OB_SUCCESS;
  if (OB_FAIL(row_store_it_.get_next_row(cur_row_))) {
    if (OB_ITER_END != ret) {
      LOG_WARN("get row from row store failed", K(ret));
    }
  } else {
    clear_evaluated_flag();
    for (int64_t i = 0; OB_SUCC(ret) && i < MY_SPEC.output_.count(); i++) {
      const ObObj& cell = cur_row_.cells_[i];
      ObDatum& datum = MY_SPEC.output_.at(i)->locate_datum_for_write(eval_ctx_);
      ObEvalInfo& eval_info = MY_SPEC.output_.at(i)->get_eval_info(eval_ctx_);
      ObExpr* expr = MY_SPEC.output_.at(i);
      if (cell.is_null()) {
        datum.set_null();
      } else if (cell.get_type() != expr->datum_meta_.type_) {
        ret = OB_ERR_UNEXPECTED;
        LOG_WARN("type mismatch", K(ret), K(i), K(cell.get_type()), K(*expr));
      } else if (OB_FAIL(datum.from_obj(cell, expr->obj_datum_map_))) {
        LOG_WARN("convert obj to datum failed", K(ret));
      } else {
        eval_info.evaluated_ = true;
      }
    }
  }
  return ret;
}

}  // end namespace sql
}  // end namespace oceanbase