/**
 * 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 "lib/utility/ob_macro_utils.h"
#include "sql/engine/expr/ob_expr_column_conv.h"
#include "sql/engine/expr/ob_datum_cast.h"
#include "sql/session/ob_sql_session_info.h"
#include "common/sql_mode/ob_sql_mode_utils.h"
#include "sql/engine/expr/ob_expr_type_to_str.h"
#include "sql/engine/ob_exec_context.h"

using namespace oceanbase::common;

namespace oceanbase
{
namespace sql
{
ObFastColumnConvExpr::ObFastColumnConvExpr(ObIAllocator &alloc)
    : ObBaseExprColumnConv(alloc),
      ObFastExprOperator(T_FUN_COLUMN_CONV),
      column_type_(alloc),
      value_item_(),
      column_info_()
{
}

int ObFastColumnConvExpr::assign(const ObFastExprOperator &other)
{
  int ret = OB_SUCCESS;
  if (OB_UNLIKELY(other.get_op_type() != T_FUN_COLUMN_CONV)) {
    ret = OB_INVALID_ARGUMENT;
    LOG_WARN("invalid argument", K(other.get_op_type()));
  } else {
    const ObFastColumnConvExpr &other_conv = static_cast<const ObFastColumnConvExpr&>(other);
    column_type_ = other_conv.column_type_;
    value_item_ = other_conv.value_item_;
    if (OB_FAIL(ob_write_string(alloc_, other_conv.column_info_, column_info_))) {
      LOG_WARN("fail to set column info", K(ret));
    }
  }
  return ret;
}

int ObFastColumnConvExpr::calc(ObExprCtx &expr_ctx, const ObNewRow &row, ObObj &result) const
{
  int ret = OB_SUCCESS;
  if (OB_UNLIKELY(OB_ISNULL(expr_ctx.my_session_))) {
    ret = OB_INVALID_ARGUMENT;
    LOG_WARN("expr context is invalid", K(ret), K(expr_ctx.my_session_), K(expr_ctx.phy_plan_ctx_));
  } else {
    bool is_strict = is_strict_mode(expr_ctx.my_session_->get_sql_mode());
    const ObObj *value = NULL;
    const ObString *column_info = NULL;
    if (has_column_info()) {
      column_info = &column_info_;
    }
    if (OB_FAIL(value_item_.get_item_value_directly(*expr_ctx.phy_plan_ctx_, row, value))) {
      LOG_WARN("get item value directly from value item failed", K(ret), K_(value_item));
    } else if (OB_FAIL(ObSqlExpressionUtil::expand_array_params(expr_ctx, *value, value))) {
      LOG_WARN("expand array params failed", K(ret));
    } else if (OB_FAIL(ObExprColumnConv::convert_skip_null_check(result, *value, column_type_,
                                         is_strict, expr_ctx.column_conv_ctx_,
                                         &str_values_, column_info))) {
      LOG_WARN("convert column value failed", K(ret), K(*this));
    }
  }
  return ret;
}

int ObFastColumnConvExpr::set_const_value(const ObObj &value)
{
  int ret = OB_SUCCESS;
  ObObj tmp;
  if (OB_FAIL(ob_write_obj(alloc_, value, tmp))) {
    LOG_WARN("write const value failed", K(ret));
  } else if (OB_FAIL(value_item_.assign(tmp))) {
    LOG_WARN("write value item failed", K(ret));
  }
  return ret;
}
//由于在14x的版本中ObExprColumnConv使用的是父类ObExprOperator的序列化函数
//为了保证兼容性，这里先序列化父类ObExprOperator的成员，再序列化自身的成员
OB_SERIALIZE_MEMBER(ObExprColumnConv, row_dimension_, real_param_num_, result_type_, input_types_, id_, str_values_);

ObExprColumnConv::ObExprColumnConv(ObIAllocator &alloc)
    : ObBaseExprColumnConv(alloc),
      ObFuncExprOperator(alloc, T_FUN_COLUMN_CONV, N_COLUMN_CONV, -1, NOT_ROW_DIMENSION,
                         INTERNAL_IN_MYSQL_MODE, INTERNAL_IN_ORACLE_MODE)
{
  disable_operand_auto_cast();
  //obexprcolumnconv有自己特殊处理，不走字符集自动转换框架
  need_charset_convert_ = false;
}

ObExprColumnConv::~ObExprColumnConv()
{
}

int ObExprColumnConv::assign(const ObExprOperator &other)
{
  int ret = OB_SUCCESS;
  const ObExprColumnConv *tmp_other = dynamic_cast<const ObExprColumnConv *>(&other);
  if (OB_UNLIKELY(NULL == tmp_other)) {
    ret = OB_INVALID_ARGUMENT;
    LOG_WARN("invalid argument. wrong type for other", K(ret), K(other));
  } else if (OB_LIKELY(this != tmp_other)) {
    if (OB_FAIL(ObFuncExprOperator::assign(other))) {
      LOG_WARN("copy in Base class ObFuncExprOperator failed", K(ret));
    } else if (tmp_other->str_values_.count() > 0 && 
               OB_FAIL(deep_copy_str_values(tmp_other->str_values_))) {
      LOG_WARN("copy str_values failed", K(ret));
    }
  }
  return ret;
}

int ObExprColumnConv::convert_with_null_check(ObObj &result,
                                              const ObObj &obj,
                                              const ObExprResType &res_type,
                                              bool is_strict,
                                              ObCastCtx &cast_ctx,
                                              const ObIArray<ObString> *type_infos)
{
  int ret = OB_SUCCESS;
  bool is_not_null = res_type.is_not_null_for_write();
  if (OB_FAIL(ObExprColumnConv::convert_skip_null_check(result, obj, res_type, is_strict,
                                                        cast_ctx, type_infos))) {
    LOG_WARN("fail to convert skip null check", K(ret));
  } else {
//  if (GET_MIN_CLUSTER_VERSION() < CLUSTER_VERSION_2220) {
      if (is_not_null && (result.is_null() || (lib::is_oracle_mode() && result.is_null_oracle()))) {
        ret = OB_BAD_NULL_ERROR;
        LOG_WARN("Column should not be null", K(ret));
//    }
    }
  }
  return ret;
}

int ObExprColumnConv::convert_skip_null_check(ObObj &result,
                                              const ObObj &obj,
                                              const ObExprResType &res_type,
                                              bool is_strict,
                                              ObCastCtx &cast_ctx,
                                              const ObIArray<ObString> *type_infos,
                                              const ObString *column_info)
{
  int ret = OB_SUCCESS;
  ObObjType type = res_type.get_type();
  const ObAccuracy &accuracy = res_type.get_accuracy();
  ObCollationType collation_type = res_type.get_collation_type();
  const ObObj *res_obj = NULL;
  cast_ctx.expect_obj_collation_ = collation_type;
  cast_ctx.dest_collation_ = collation_type;

  ObAccuracy tmp_accuracy = accuracy;
  cast_ctx.res_accuracy_ = &tmp_accuracy;
  if (OB_UNLIKELY(ob_is_enum_or_set_type(type))) {
    ObExpectType expect_type;
    expect_type.set_type(type);
    expect_type.set_collation_type(collation_type);
    expect_type.set_type_infos(type_infos);
    if (OB_FAIL(ObObjCaster::to_type(expect_type, cast_ctx, obj, result))) {
      LOG_WARN("fail to cast to enum or set", K(obj), K(expect_type), K(ret));
    } else {
      res_obj = &result;
    }
  } else if (OB_FAIL(ObObjCaster::to_type(type, cast_ctx, obj, result, res_obj)) || OB_ISNULL(res_obj)) {
    ret = COVER_SUCC(OB_ERR_UNEXPECTED);
    LOG_WARN("failed to cast object", K(ret), K(obj), "type", type);
  } else {
    LOG_DEBUG("succ to to_type", K(type), K(obj), K(result), K(collation_type));
  }
  if (OB_SUCC(ret)) {
    const int64_t max_accuracy_len = static_cast<int64_t>(res_type.
                                                          get_accuracy().get_length());
    const int64_t str_len_byte = static_cast<int64_t>(result.get_string_len());
    if (OB_FAIL(obj_collation_check(is_strict, collation_type, *const_cast<ObObj*>(res_obj)))) {
      LOG_WARN("failed to check collation", K(ret), K(collation_type), KPC(res_obj));
    } else if (OB_FAIL(obj_accuracy_check(cast_ctx, accuracy, collation_type, *res_obj, result, res_obj))) {
      LOG_WARN("failed to check accuracy", K(ret), K(accuracy), K(collation_type), KPC(res_obj));
      if (OB_ERR_DATA_TOO_LONG == ret && lib::is_oracle_mode()
          && OB_NOT_NULL(column_info) && !column_info->empty()) {
        ObString column_info_connection;
        ObArenaAllocator allocator;
        ObSQLUtils::copy_and_convert_string_charset(allocator, *column_info,
                                                    column_info_connection, CS_TYPE_UTF8MB4_BIN,
                                                    cast_ctx.dtc_params_.connection_collation_);
        LOG_ORACLE_USER_ERROR(OB_ERR_DATA_TOO_LONG_MSG_FMT_V2, column_info_connection.length(),
                              column_info_connection.ptr(), str_len_byte, max_accuracy_len);
      }
    }
  }
  if (OB_SUCC(ret)) {
    if (res_obj != &result) {
      //res_obj没有指向result的地址，需要将res_obj的值拷贝到result中
      result = *res_obj;
    }
//    if (is_not_null && (result.is_null() || (is_oracle_mode() && result.is_null_oracle()))) {
//      ret = OB_BAD_NULL_ERROR;
//      LOG_WARN("Column should not be null", K(ret));
//    }
  }
  return ret;
}

int ObExprColumnConv::calc_result_typeN(ObExprResType &type,
                                        ObExprResType *types,
                                        int64_t param_num,
                                        common::ObExprTypeCtx &type_ctx) const
{
  int ret = common::OB_SUCCESS;
  //objs[0]  type
  //objs[1] collation_type
  //objs[2] accuray_expr
  //objs[3] nullable_expr
  //objs[4] value
  //objs[5] column_info
  ObCollationType coll_type = CS_TYPE_INVALID;
  if (OB_ISNULL(type_ctx.get_session()) || OB_ISNULL(type_ctx.get_raw_expr())) {
    ret = OB_ERR_UNEXPECTED;
    LOG_WARN("session is NULL or raw expr is NULL", K(ret));
  } else if (OB_UNLIKELY(((PARAMS_COUNT_WITHOUT_COLUMN_INFO != param_num)
                        && (PARAMS_COUNT_WITH_COLUMN_INFO != param_num))
                        || OB_ISNULL(types))) {
    ret = OB_INVALID_ARGUMENT;
    SQL_ENG_LOG(WARN, "invalid argument, param_num should be 5 or 6",
               K(param_num), K(types), K(ret));
  } else if (OB_FAIL(type_ctx.get_session()->get_collation_connection(coll_type))) {
    SQL_ENG_LOG(WARN, "fail to get_collation_connection", K(coll_type), K(ret));
  } else {
    type.set_type(types[0].get_type());
    type.set_collation_type(types[1].get_collation_type());
    type.set_collation_level(common::CS_LEVEL_IMPLICIT);
    type.set_accuracy(types[2].get_accuracy());
    if (types[3].is_not_null_for_read()) {
      type.set_result_flag(NOT_NULL_FLAG | NOT_NULL_WRITE_FLAG);
    }

    bool enumset_to_varchar = false;
    //here will wrap type_to_str if necessary
    if (ob_is_enumset_tc(types[4].get_type())) {
      ObObjType calc_type = enumset_calc_types_[OBJ_TYPE_TO_CLASS[types[0].get_type()]];
      if (OB_UNLIKELY(ObMaxType == calc_type)) {
        ret = OB_ERR_UNEXPECTED;
        SQL_ENG_LOG(WARN, "invalid type of parameter ", K(types[4]), K(types), K(ret));
      } else if (ObVarcharType == calc_type) {
        enumset_to_varchar = true;
        types[4].set_calc_type(calc_type);
        types[4].set_calc_collation_type(coll_type);
        types[4].set_calc_collation_level(CS_LEVEL_IMPLICIT);
        type_ctx.set_cast_mode(type_ctx.get_cast_mode() | type_ctx.get_raw_expr()->get_extra());
      }
    }
    // for table modify in oracle mode, we ignore charset convert failed
    if (OB_SUCC(ret) && lib::is_oracle_mode()) {
      type_ctx.set_cast_mode(type_ctx.get_cast_mode() | CM_CHARSET_CONVERT_IGNORE_ERR);
    }

    if (OB_SUCC(ret) && !enumset_to_varchar) {
      //cast type when type not same.
      const ObObjTypeClass value_tc = ob_obj_type_class(types[4].get_type());
      const ObObjTypeClass type_tc = ob_obj_type_class(types[0].get_type());
      if (lib::is_oracle_mode()
          && OB_UNLIKELY(!cast_supported(types[4].get_type(), types[4].get_collation_type(),
                                         types[0].get_type(), types[1].get_collation_type()))) {
        ret = OB_ERR_INVALID_TYPE_FOR_OP;
        LOG_WARN("inconsistent datatypes", "expected", type_tc, "got", value_tc);
      } else {
        type_ctx.set_cast_mode(
            type_ctx.get_cast_mode() | type_ctx.get_raw_expr()->get_extra() | CM_COLUMN_CONVERT);
        types[4].set_calc_meta(type);
      }
    }
    LOG_DEBUG("finish calc_result_typeN", K(type), K(types[4]), K(types[0]), K(enumset_to_varchar));
  }
  return ret;
}

int ObExprColumnConv::cg_expr(ObExprCGCtx &op_cg_ctx,
                              const ObRawExpr &raw_expr,
                              ObExpr &rt_expr) const
{
  int ret = OB_SUCCESS;
  UNUSED(raw_expr);
  //compatible with old code
  CK((PARAMS_COUNT_WITHOUT_COLUMN_INFO == rt_expr.arg_cnt_)
    || (PARAMS_COUNT_WITH_COLUMN_INFO == rt_expr.arg_cnt_));
  if (OB_ISNULL(op_cg_ctx.session_)) {
    ret = OB_ERR_UNEXPECTED;
    LOG_WARN("exec ctx is null", K(ret));
  } else if (OB_FAIL(ObEnumSetInfo::init_enum_set_info(op_cg_ctx.allocator_, rt_expr, type_,
      raw_expr.get_extra(), str_values_))) {
    LOG_WARN("fail to init_enum_set_info", K(ret), K(type_), K(str_values_));
  } else {
    if (op_cg_ctx.session_->is_ignore_stmt()) {
      ObEnumSetInfo *enumset_info = static_cast<ObEnumSetInfo *>(rt_expr.extra_info_);
      enumset_info->cast_mode_ = enumset_info->cast_mode_ | CM_WARN_ON_FAIL
                                | CM_CHARSET_CONVERT_IGNORE_ERR;
    }
    rt_expr.eval_func_ = column_convert;
  }
  return ret;
}

int ObExprColumnConv::column_convert(const ObExpr &expr,
                                     ObEvalCtx &ctx,
                                     ObDatum &datum)
{
  int ret = OB_SUCCESS;
  int warning = OB_SUCCESS;
  if (OB_ISNULL(expr.extra_info_)) {
    ret = OB_ERR_UNEXPECTED;
    LOG_WARN("extra_info_ is unexpected", K(ret), KP(expr.extra_info_));
  } else {
    const ObEnumSetInfo *enumset_info = static_cast<ObEnumSetInfo *>(expr.extra_info_);
    const uint64_t cast_mode = enumset_info->cast_mode_;
    bool is_strict = CM_IS_STRICT_MODE(cast_mode);
    ObObjType out_type = expr.datum_meta_.type_;
    ObCollationType out_cs_type = expr.datum_meta_.cs_type_;
    ObDatum *val = NULL;
    if (ob_is_enum_or_set_type(out_type) && !expr.args_[4]->obj_meta_.is_enum_or_set()) {
      ObExpr *old_expr = expr.args_[0];
      expr.args_[0] = expr.args_[4];
      if (OB_FAIL(expr.eval_enumset(ctx, enumset_info->str_values_, cast_mode, val))) {
        LOG_WARN("fail to eval_enumset", KPC(enumset_info), K(ret));
      }
      expr.args_[0] = old_expr;
    } else {
      if (OB_FAIL(expr.args_[4]->eval(ctx, val))) {
        LOG_WARN("evaluate parameter failed", K(ret));
      }
    }

    if (OB_FAIL(ret)) {
    } else if (val->is_null()) {
      datum.set_null();
    } else {
      if (ob_is_string_type(out_type)) {
        ObString str = val->get_string();
        if (OB_FAIL(string_collation_check(is_strict, out_cs_type, out_type, str))) {
          LOG_WARN("fail to check collation", K(ret), K(str), K(is_strict), K(expr));
        } else {
          val->set_string(str);
        }
      }
      if (OB_SUCC(ret)) {
        const int64_t max_accuracy_len = static_cast<int64_t>(expr.max_length_);
        const int64_t str_len_byte = static_cast<int64_t>(val->len_);
        if (OB_FAIL(datum_accuracy_check(expr,
                                         cast_mode,
                                         ctx,
                                         *val,
                                         datum,
                                         warning))) {
          LOG_WARN("fail to check accuracy", K(ret), K(expr), K(warning));
          //compatible with old code
          if (OB_ERR_DATA_TOO_LONG == ret && lib::is_oracle_mode()
              && PARAMS_COUNT_WITH_COLUMN_INFO == expr.arg_cnt_) {
            ObString column_info_str;
            ObDatum *column_info = NULL;
            if (OB_FAIL(expr.args_[5]->eval(ctx, column_info))) {
              LOG_WARN("evaluate parameter failed", K(ret));
            } else {
              column_info_str = column_info->get_string();
              LOG_ORACLE_USER_ERROR(OB_ERR_DATA_TOO_LONG_MSG_FMT_V2, column_info_str.length(),
                                    column_info_str.ptr(), str_len_byte, max_accuracy_len);
            }
            ret = OB_ERR_DATA_TOO_LONG;
          }
        }
      }
      LOG_DEBUG("after column convert", K(expr), K(datum), K(cast_mode));
    }
  }

  return ret;
}

//TODO(yaoying.yyy):(duplicate_with_type_to_str, remove later
int ObBaseExprColumnConv::shallow_copy_str_values(const common::ObIArray<common::ObString> &str_values)
{
  int ret = OB_SUCCESS;
  str_values_.reset();
  if (OB_UNLIKELY(str_values.count() < 1)) {
    ret = OB_INVALID_ARGUMENT;
    LOG_WARN("invalid str_values", K(str_values), K(ret));
  } else if (OB_FAIL(str_values_.assign(str_values))) {
    LOG_WARN("fail to assign str values", K(ret));
  } else {/*do nothing*/}
  return ret;
}

int ObBaseExprColumnConv::deep_copy_str_values(const ObIArray<ObString> &str_values)
{
  int ret = OB_SUCCESS;
  str_values_.reset();
  if (OB_UNLIKELY(str_values.count() < 1)) {
    ret = OB_INVALID_ARGUMENT;
    LOG_WARN("invalid str_values", K(str_values), K(ret));
  } else if (OB_FAIL(str_values_.reserve(str_values.count()))) {
    LOG_WARN("fail to init str_values_", K(ret));
  } else {/*do nothing*/}

  for (int64_t i = 0; OB_SUCC(ret) && i < str_values.count(); ++i) {
    const ObString &str = str_values.at(i);
    char *buf = NULL;
    ObString str_tmp;
    if (str.empty()) {
      //just keep str_tmp empty
    } else if (OB_UNLIKELY(NULL == (buf = static_cast<char *>(alloc_.alloc(str.length()))))) {
      ret = common::OB_ALLOCATE_MEMORY_FAILED;
      LOG_WARN("failed to allocate memory", K(i), K(str), K(ret));
    } else {
      MEMCPY(buf, str.ptr(), str.length());
      str_tmp.assign_ptr(buf, str.length());
    }

    if (OB_SUCC(ret)) {
      if (OB_FAIL(str_values_.push_back(str_tmp))) {
        LOG_WARN("failed to push back str", K(i), K(str_tmp), K(str), K(ret));
      }
    }
  }
  return ret;
}
}//sql
}//oceanbase