/**
 * 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 "sql/engine/expr/ob_expr_is.h"
#include "share/object/ob_obj_cast.h"
//#include "sql/engine/expr/ob_expr_promotion_util.h"
#include "sql/parser/ob_item_type.h"
#include "sql/session/ob_sql_session_info.h"
#include "share/config/ob_server_config.h"

namespace oceanbase {
using namespace common;
namespace sql {

ObExprIsBase::ObExprIsBase(ObIAllocator& alloc, ObExprOperatorType type, const char* name)
    : ObRelationalExprOperator(alloc, type, name, 3){};

int ObExprIsBase::calc_result_type3(ObExprResType& type, ObExprResType& type1, ObExprResType& type2,
    ObExprResType& type3, ObExprTypeCtx& type_ctx) const
{
  int ret = OB_SUCCESS;
  const ObSQLSessionInfo* session = static_cast<const ObSQLSessionInfo*>(type_ctx.get_session());
  if (!session->use_static_typing_engine()) {
    ObExprResType tmp_type2;
    if (lib::is_oracle_mode() && type1.is_ext()) {
      type.set_int32();  // not tinyint, compatible with MySQL
      type.set_precision(DEFAULT_PRECISION_FOR_BOOL);
      type.set_scale(DEFAULT_SCALE_FOR_INTEGER);
      type.set_calc_type(type1.get_calc_type());
      type.set_result_flag(OB_MYSQL_NOT_NULL_FLAG);
      type2.set_calc_type(type2.get_type());
    } else {
      if (OB_FAIL(tmp_type2.assign(type2))) {
        LOG_WARN("failed to copy type", K(ret), K(type2));
      } else if (OB_FAIL(ObRelationalExprOperator::calc_result_type2(type, type1, tmp_type2, type_ctx))) {
        LOG_WARN("failed to calc result type", K(ret), K(type1), K(tmp_type2));
      } else {
        // always allow NULL value
        type.set_result_flag(OB_MYSQL_NOT_NULL_FLAG);
        type2.set_calc_type(type2.get_type());
      }
    }
  } else {
    // TODO  add collection process for PL
    ObRawExpr* raw_expr = get_raw_expr();
    ObOpRawExpr* op_expr = static_cast<ObOpRawExpr*>(raw_expr);
    if (OB_ISNULL(op_expr) || OB_UNLIKELY(op_expr->get_param_count() != 3)) {
      ret = OB_ERR_UNEXPECTED;
      LOG_WARN("op raw expr is null", K(ret), K(op_expr));
    } else {
      // always allow NULL value
      type.set_result_flag(OB_MYSQL_NOT_NULL_FLAG);
      type2.set_calc_type(type2.get_type());
      type3.set_calc_type(type3.get_type());

      ObRawExpr* param2 = op_expr->get_param_expr(1);
      ObConstRawExpr* const_param2 = static_cast<ObConstRawExpr*>(param2);
      ObRawExpr* param3 = op_expr->get_param_expr(2);
      ObConstRawExpr* const_param3 = static_cast<ObConstRawExpr*>(param3);
      if (OB_ISNULL(const_param2) || OB_ISNULL(const_param3)) {
        ret = OB_ERR_UNEXPECTED;
        LOG_WARN("second or third child of is expr is null", K(ret), K(const_param2), K(const_param3));
      } else if (!const_param2->get_value().is_null()) {  // is true/false
        if (ob_is_numeric_type(type1.get_type())) {
          type1.set_calc_meta(type1.get_obj_meta());
          type1.set_calc_accuracy(type1.get_accuracy());
        } else {
          type1.set_calc_type(ObNumberType);
          const ObAccuracy& calc_acc = ObAccuracy::DDL_DEFAULT_ACCURACY2[0][ObNumberType];
          type1.set_calc_accuracy(calc_acc);
        }
      } else {  // is null
        if (const_param3->get_value().is_true()) {
          type1.set_calc_type(ObIntType);
        } else {
          type1.set_calc_type(type1.get_type());
        }
        // query range extract check the calc type of %type.
        type.set_calc_meta(type1.get_calc_meta());
      }
      type.set_type(ObInt32Type);
      type.set_precision(DEFAULT_PRECISION_FOR_BOOL);
      type.set_scale(DEFAULT_SCALE_FOR_INTEGER);
    }
    type_ctx.set_cast_mode(type_ctx.get_cast_mode() | CM_NO_RANGE_CHECK);
  }
  return ret;
}

int ObExprIs::calc_with_null(
    common::ObObj& result, const ObObj& obj1, const ObObj& obj2, const ObObj& obj3, ObCastCtx& cast_ctx) const
{
  int ret = OB_SUCCESS;
  bool ret_bool = false;
  UNUSED(obj2);
  UNUSED(cast_ctx);
  if (obj3.is_true()) {
    if (obj1.is_null()) {
      ret_bool = true;
    } else {
      int64_t int_val = 0;
      EXPR_GET_INT64_V2(obj1, int_val);
      if (OB_SUCC(ret)) {
        if (int_val == 0) {
          ret_bool = true;
        } else {
          ret_bool = false;
        }
      }
    }
  } else {
    if (lib::is_oracle_mode() && obj1.get_meta().is_ext()) {
      ret = OB_NOT_SUPPORTED;
    } else {
      ret_bool = obj1.is_null();
    }
  }

  if (OB_SUCC(ret)) {
    result.set_int32(static_cast<int32_t>(ret_bool));
  }

  return ret;
}

int ObExprIsNot::calc_with_null(
    ObObj& result, const ObObj& obj1, const ObObj& obj2, const ObObj& obj3, ObCastCtx& cast_ctx) const
{
  int ret = OB_SUCCESS;
  UNUSED(obj2);
  UNUSED(obj3);
  UNUSED(cast_ctx);
  bool ret_bool = false;
  if (lib::is_oracle_mode() && obj1.get_meta().is_ext()) {
    ret = OB_NOT_SUPPORTED;
  } else {
    ret_bool = !obj1.is_null();
  }
  result.set_int32(static_cast<int32_t>(ret_bool));
  return ret;
}

int ObExprIsBase::calc_with_int_internal(
    ObObj& result, const ObObj& obj1, const ObObj& obj2, ObCastCtx& cast_ctx, bool is_not) const
{
  int ret = OB_SUCCESS;
  bool ret_bool = false;
  if (obj1.is_null()) {
    ret_bool = is_not;
  } else if (obj1.is_tinyint()) {
    ret_bool = is_not ? obj1.get_bool() != obj2.get_bool() : obj1.get_bool() == obj2.get_bool();
  } else {
    int64_t int_val = 0;
    EXPR_GET_INT64_V2(obj1, int_val);
    if (OB_SUCC(ret)) {
      if ((int_val != 0 && obj2.get_bool() == is_not) || (int_val == 0 && obj2.get_bool() == !is_not)) {
        ret_bool = false;
      } else {
        ret_bool = true;
      }
    } else {
      ret = OB_SUCCESS;
      if (obj2.get_bool() == is_not) {
        ret_bool = true;
      } else {
        ret_bool = false;
      }
    }
  }
  if (OB_SUCC(ret)) {
    result.set_int32(static_cast<int32_t>(ret_bool));
  }
  return ret;
}

int ObExprIs::calc_with_int(ObObj& result, const ObObj& obj1, const ObObj& obj2, ObCastCtx& cast_ctx) const
{
  return calc_with_int_internal(result, obj1, obj2, cast_ctx, false);
}

int ObExprIsNot::calc_with_int(ObObj& result, const ObObj& obj1, const ObObj& obj2, ObCastCtx& cast_ctx) const
{
  return calc_with_int_internal(result, obj1, obj2, cast_ctx, true);
}

// is null/true/false
int ObExprIsBase::calc(
    ObObj& result, const ObObj& obj1, const ObObj& obj2, const ObObj& obj3, ObCastCtx& cast_ctx) const
{
  int ret = OB_SUCCESS;
  if (OB_UNLIKELY(!obj2.is_null() && !obj2.is_tinyint())) {
    LOG_USER_ERROR(OB_INVALID_ARGUMENT_FOR_IS, to_cstring(obj1));
    ret = OB_INVALID_ARGUMENT_FOR_IS;
    LOG_WARN("invalid type for is operator", K(obj2));
  } else {
    if (obj2.is_null()) {
      ret = calc_with_null(result, obj1, obj2, obj3, cast_ctx);
    } else if (obj2.is_tinyint()) {
      ret = calc_with_int(result, obj1, obj2, cast_ctx);
    }  // end else
  }
  return ret;
}
// the 3rd obj is used for this special case:
// 'select * from t1 where c1 is null' can get rows with c1 is '0000-00-00' in mysql mode.
int ObExprIsBase::calc_result3(
    ObObj& result, const ObObj& obj1, const ObObj& obj2, const ObObj& obj3, common::ObExprCtx& expr_ctx) const
{
  EXPR_DEFINE_CAST_CTX(expr_ctx, CM_WARN_ON_FAIL);
  return calc(result, obj1, obj2, obj3, cast_ctx);
}

int ObExprIsBase::cg_expr_internal(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr,
    const ObConstRawExpr*& const_param2, const ObConstRawExpr*& const_param3) const
{
  UNUSED(op_cg_ctx);
  int ret = OB_SUCCESS;
  const ObOpRawExpr* op_raw_expr = static_cast<const ObOpRawExpr*>(&raw_expr);
  if (rt_expr.arg_cnt_ != 3) {
    ret = OB_INVALID_ARGUMENT;
    LOG_WARN("isnot expr should have 3 params", K(ret), K(rt_expr.arg_cnt_));
  } else if (OB_ISNULL(rt_expr.args_) || OB_ISNULL(rt_expr.args_[0]) || OB_ISNULL(rt_expr.args_[1]) ||
             OB_ISNULL(rt_expr.args_[2])) {
    ret = OB_ERR_UNEXPECTED;
    LOG_WARN("children of isnot expr is null", K(ret), K(rt_expr.args_));
  } else {
    const ObRawExpr* param2 = op_raw_expr->get_param_expr(1);
    const ObRawExpr* param3 = op_raw_expr->get_param_expr(2);
    const_param2 = static_cast<const ObConstRawExpr*>(param2);
    const_param3 = static_cast<const ObConstRawExpr*>(param3);
  }
  return ret;
}

#define EVAL_FUNC(type)                           \
  if (is_not && is_true) {                        \
    eval_func = ObExprIsNot::type##_is_not_true;  \
  } else if (is_not && !is_true) {                \
    eval_func = ObExprIsNot::type##_is_not_false; \
  } else if (!is_not && is_true) {                \
    eval_func = ObExprIs::type##_is_true;         \
  } else if (!is_not && !is_true) {               \
    eval_func = ObExprIs::type##_is_false;        \
  }

int ObExprIsBase::cg_result_type_class(ObObjType type, ObExpr::EvalFunc& eval_func, bool is_not, bool is_true) const
{
  int ret = OB_SUCCESS;
  switch (type) {
    case ObTinyIntType:
    case ObSmallIntType:
    case ObMediumIntType:
    case ObInt32Type:
    case ObIntType:
    case ObUTinyIntType:
    case ObUSmallIntType:
    case ObUMediumIntType:
    case ObUInt32Type:
    case ObUInt64Type:
    case ObBitType: {
      EVAL_FUNC(int);
      break;
    }
    case ObFloatType:
    case ObUFloatType: {
      EVAL_FUNC(float);
      break;
    }
    case ObDoubleType:
    case ObUDoubleType: {
      EVAL_FUNC(double);
      break;
    }
    case ObMaxType: {
      ret = OB_ERR_UNEXPECTED;
      LOG_WARN("is expr got unexpected type param", K(ret), K(type));
      break;
    }
    default: {
      EVAL_FUNC(number);
      break;
    }
  }
  return ret;
}

int ObExprIs::cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const
{
  int ret = OB_SUCCESS;
  const ObConstRawExpr* param2 = NULL;
  const ObConstRawExpr* param3 = NULL;
  ObObjType param1_type = ObMaxType;
  if (OB_FAIL(cg_expr_internal(op_cg_ctx, raw_expr, rt_expr, param2, param3))) {
    LOG_WARN("cg_expr_inner failed", K(ret));
  } else if (OB_ISNULL(param2) || OB_ISNULL(param3)) {
    ret = OB_ERR_UNEXPECTED;
    LOG_WARN("const raw expr param2 or param3 is null", K(param2), K(param3));
  } else if (FALSE_IT(param1_type = rt_expr.args_[0]->datum_meta_.type_)) {
  } else if (param3->get_value().is_true()) {  // special case: date value is '0000-00-00'.
    rt_expr.eval_func_ = ObExprIs::calc_is_date_int_null;
  } else if (param2->get_value().is_null()) {  // c1 is null
    rt_expr.eval_func_ = ObExprIs::calc_is_null;
  } else if (param2->get_value().is_true()) {
    if (OB_FAIL(cg_result_type_class(param1_type, rt_expr.eval_func_, false, true))) {
      LOG_WARN("is expr got unexpected type param", K(ret));
    }
  } else if (param2->get_value().is_false()) {
    if (OB_FAIL(cg_result_type_class(param1_type, rt_expr.eval_func_, false, false))) {
      LOG_WARN("is expr got unexpected type param", K(ret));
    }
  } else {
    ret = OB_ERR_UNEXPECTED;
    LOG_WARN("second param of is expr is not null, true or false", K(ret), K(param2->get_value()));
  }
  return ret;
}

int ObExprIsNot::cg_expr(ObExprCGCtx& op_cg_ctx, const ObRawExpr& raw_expr, ObExpr& rt_expr) const
{
  int ret = OB_SUCCESS;
  const ObConstRawExpr* param2 = NULL;
  const ObConstRawExpr* param3 = NULL;
  ObObjType param1_type = ObMaxType;
  if (OB_FAIL(cg_expr_internal(op_cg_ctx, raw_expr, rt_expr, param2, param3))) {
    LOG_WARN("cg_expr_inner failed", K(ret));
  } else if (OB_ISNULL(param2) || OB_ISNULL(param3)) {
    ret = OB_ERR_UNEXPECTED;
    LOG_WARN("const raw expr param2 or param3 is null", K(param2), K(param3));
  } else if (FALSE_IT(param1_type = rt_expr.args_[0]->datum_meta_.type_)) {
  } else if (param2->get_value().is_null()) {  // c1 is null
    rt_expr.eval_func_ = ObExprIsNot::calc_is_not_null;
  } else if (param2->get_value().is_true()) {
    if (OB_FAIL(cg_result_type_class(param1_type, rt_expr.eval_func_, true, true))) {
      LOG_WARN("is expr got unexpected type param", K(ret));
    }
  } else if (param2->get_value().is_false()) {
    if (OB_FAIL(cg_result_type_class(param1_type, rt_expr.eval_func_, true, false))) {
      LOG_WARN("is expr got unexpected type param", K(ret));
    }
  } else {
    ret = OB_ERR_UNEXPECTED;
    LOG_WARN("second param of is expr is not null, true, false or infinite or nan", K(ret), K(param2->get_value()));
  }
  return ret;
}

int ObExprIs::calc_is_date_int_null(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum)
{
  int ret = OB_SUCCESS;
  ObDatum* param1 = NULL;
  if (OB_FAIL(expr.args_[0]->eval(ctx, param1))) {
    LOG_WARN("eval first param failed", K(ret));
  } else {
    bool ret_bool = param1->is_null() || param1->get_int() == 0;
    expr_datum.set_int32(static_cast<int32_t>(ret_bool));
  }
  return ret;
}

int ObExprIs::calc_is_null(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum)
{
  int ret = OB_SUCCESS;
  ObDatum* param1 = NULL;
  if (OB_FAIL(expr.args_[0]->eval(ctx, param1))) {
    LOG_WARN("eval first param failed", K(ret));
  } else {
    bool ret_bool = param1->is_null();
    expr_datum.set_int32(static_cast<int32_t>(ret_bool));
  }
  return ret;
}

int ObExprIsNot::calc_is_not_null(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum)
{
  int ret = OB_SUCCESS;
  ObDatum* param1 = NULL;
  if (OB_FAIL(expr.args_[0]->eval(ctx, param1))) {
    LOG_WARN("eval first param failed", K(ret));
  } else {
    bool ret_bool = !param1->is_null();
    expr_datum.set_int32(static_cast<int32_t>(ret_bool));
  }
  return ret;
}

template <typename T>
int ObExprIsBase::is_zero(T number)
{
  return 0 == number;
}
template <>
int ObExprIsBase::is_zero<number::ObCompactNumber>(number::ObCompactNumber number)
{
  return number.is_zero();
}

#define NUMERIC_CALC_FUNC(type, func_name, bool_is_not, is_true, str_is_not)                              \
  int func_name::type##_##str_is_not##_##is_true(const ObExpr& expr, ObEvalCtx& ctx, ObDatum& expr_datum) \
  {                                                                                                       \
    int ret = OB_SUCCESS;                                                                                 \
    ObDatum* param1 = NULL;                                                                               \
    bool ret_bool = false;                                                                                \
    if (OB_FAIL(expr.args_[0]->eval(ctx, param1))) {                                                      \
      LOG_WARN("eval first param failed", K(ret));                                                        \
    } else if (param1->is_null()) {                                                                       \
      ret_bool = bool_is_not;                                                                             \
    } else {                                                                                              \
      ret_bool = bool_is_not == is_true ? is_zero(param1->get_##type()) : !is_zero(param1->get_##type()); \
    }                                                                                                     \
    if (OB_SUCC(ret)) {                                                                                   \
      expr_datum.set_int32(static_cast<int32_t>(ret_bool));                                               \
    }                                                                                                     \
    return ret;                                                                                           \
  }

NUMERIC_CALC_FUNC(int, ObExprIsNot, true, true, is_not)
NUMERIC_CALC_FUNC(float, ObExprIsNot, true, true, is_not)
NUMERIC_CALC_FUNC(double, ObExprIsNot, true, true, is_not)
NUMERIC_CALC_FUNC(number, ObExprIsNot, true, true, is_not)

NUMERIC_CALC_FUNC(int, ObExprIsNot, true, false, is_not)
NUMERIC_CALC_FUNC(float, ObExprIsNot, true, false, is_not)
NUMERIC_CALC_FUNC(double, ObExprIsNot, true, false, is_not)
NUMERIC_CALC_FUNC(number, ObExprIsNot, true, false, is_not)

NUMERIC_CALC_FUNC(int, ObExprIs, false, true, is)
NUMERIC_CALC_FUNC(float, ObExprIs, false, true, is)
NUMERIC_CALC_FUNC(double, ObExprIs, false, true, is)
NUMERIC_CALC_FUNC(number, ObExprIs, false, true, is)

NUMERIC_CALC_FUNC(int, ObExprIs, false, false, is)
NUMERIC_CALC_FUNC(float, ObExprIs, false, false, is)
NUMERIC_CALC_FUNC(double, ObExprIs, false, false, is)
NUMERIC_CALC_FUNC(number, ObExprIs, false, false, is)
}  // namespace sql
}  // namespace oceanbase