/**
 * 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 SERVER
#include "observer/mysql/ob_mysql_result_set.h"

#include "observer/mysql/obsm_utils.h"
#include "lib/container/ob_array.h"
#include "rpc/obmysql/ob_mysql_field.h"
#include "observer/ob_server.h"
#include "share/ob_lob_access_utils.h"

using namespace oceanbase::common;
using namespace oceanbase::observer;
using namespace oceanbase::obmysql;

int ObMySQLResultSet::to_mysql_field(const ObField &field, ObMySQLField &mfield)
{
  int ret = OB_SUCCESS;
  mfield.dname_ = field.dname_;
  mfield.tname_ = field.tname_;
  mfield.org_tname_ = field.org_tname_;
  mfield.cname_ = field.cname_;
  mfield.org_cname_ = field.org_cname_;

  if (OB_SUCC(ret)) {
    mfield.accuracy_ = field.accuracy_;
    // mfield.type_ = oceanbase::obmysql::MYSQL_TYPE_LONG;
    // mfield.default_value_ = field.default_value_;

    // To distinguish between binary and nonbinary data for string data types,
    // check whether the charsetnr value is 63. Also, flag must be set to binary accordingly
    mfield.charsetnr_ = field.charsetnr_;
    mfield.flags_ = field.flags_;
    mfield.length_ = field.length_;

    // 对于Varchar类，检查charset：
    mfield.flags_ &= (~BINARY_FLAG);
    bool is_oracle_lob = false;
    if (ObLongTextType == field.type_.get_type() && lib::is_oracle_mode()) { // was ObLobType
      is_oracle_lob = true;
    }
    if (ob_is_string_type(field.type_.get_type())
        && ObCharset::is_valid_collation(static_cast<ObCollationType>(field.charsetnr_))
        && ObCharset::is_bin_sort(static_cast<ObCollationType>(field.charsetnr_))
        && !is_oracle_lob) {
      mfield.flags_ |= BINARY_FLAG;
    }

    ObScale decimals = mfield.accuracy_.get_scale();
    ObPrecision pre = mfield.accuracy_.get_precision();
    // TIMESTAMP、UNSIGNED通过map直接映射
    if (0 == field.type_name_.case_compare("SYS_REFCURSOR")) {
      mfield.type_ = MYSQL_TYPE_CURSOR;
    } else {
      ret = ObSMUtils::get_mysql_type(field.type_.get_type(), mfield.type_, mfield.flags_, decimals);
    }
    if (OB_SUCC(ret) && is_oracle_lob) {
      mfield.flags_ &= (~BLOB_FLAG); // was ObLobType
    }

    mfield.type_owner_ = field.type_owner_;
    mfield.type_name_ = field.type_name_;
   //  In this scenario, the precsion and scale of number are undefined,
   //  and the internal implementation of ob is represented by an illegal value (-1, -85).
   //  However, oracle is represented by 0. In order to be compatible with
   //  the behavior of oracle, it is corrected to 0 here.
    if ((ObNumberType == field.type_.get_type()
          || ObUNumberType == field.type_.get_type())
        && lib::is_oracle_mode()) { // was decimal
      decimals = (decimals==NUMBER_SCALE_UNKNOWN_YET ? 0:decimals);
      pre = (pre==PRECISION_UNKNOWN_YET ? 0:pre);
    }
    mfield.accuracy_.set_precision(pre);
    mfield.accuracy_.set_scale(decimals);
    mfield.inout_mode_ = field.inout_mode_;
    if (OB_SUCC(ret)
        && ObExtendType == field.type_.get_type() && mfield.type_name_.empty()) {
      // anonymous collection
      uint16_t flags;
      ObScale num_decimals;
      ret = ObSMUtils::get_mysql_type(
        field.default_value_.get_type(), mfield.default_value_, flags, num_decimals);
    }
    if (OB_SUCC(ret)
        && EMySQLFieldType::MYSQL_TYPE_BIT == mfield.type_
        && 1 != mfield.accuracy_.get_precision()) {
      // bit(1) flags -> UNSIGNED
      // bit(2) flags -> BINARY_FLAG | BLOB_FLAG | UNSIGNED
      mfield.flags_ |= BINARY_FLAG;
      mfield.flags_ |= BLOB_FLAG;
    }
    if (field.is_hidden_rowid_) {
      mfield.inout_mode_ |= 0x04;
    }
  }
  LOG_TRACE("to mysql field", K(ret), K(mfield), K(field));
  return ret;
}

int ObMySQLResultSet::next_field(ObMySQLField &obmf)
{
  int ret = OB_SUCCESS;
  int64_t field_cnt = 0;
  const ColumnsFieldIArray *fields = get_field_columns();
  if (OB_ISNULL(fields)) {
    ret = OB_INVALID_ARGUMENT;
  } else {
    field_cnt = get_field_cnt();
    if (field_index_ >= field_cnt) {
      ret = OB_ITER_END;
    } else {
      const ObField &field = fields->at(field_index_++);
      if (OB_FAIL(to_mysql_field(field, obmf))) {
        // do nothing
      } else {
        replace_lob_type(get_session(), field, obmf);
      }
    }
  }
  set_errcode(ret);
  return ret;
}

int ObMySQLResultSet::next_param(ObMySQLField &obmf)
{
  int ret = OB_SUCCESS;
  const ParamsFieldIArray *params = get_param_fields();
  if (OB_ISNULL(params)) {
    ret = OB_INVALID_ARGUMENT;
  } else {
    const int64_t param_cnt = params->count();
    if (param_index_ >= param_cnt) {
      ret = OB_ITER_END;
    }
    if (OB_SUCC(ret)) {
      ObField field;
      ret = params->at(param_index_++, field);
      if (OB_SUCC(ret)) {
        if (OB_FAIL(to_mysql_field(field, obmf))) {
          // do nothing
        } else {
          replace_lob_type(get_session(), field, obmf);
        }
      }
    }
  }
  set_errcode(ret);
  return ret;
}