/**
 *   Copyright 2011-2015 Quickstep Technologies LLC.
 *   Copyright 2015 Pivotal Software, Inc.
 *
 *   Licensed 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 "expressions/scalar/ScalarBinaryExpression.hpp"

#include <memory>
#include <string>
#include <utility>
#include <vector>

#include "catalog/CatalogTypedefs.hpp"
#include "expressions/Expressions.pb.h"
#include "storage/ValueAccessor.hpp"
#include "types/Type.hpp"
#include "types/TypeErrors.hpp"
#include "types/TypedValue.hpp"
#include "types/containers/ColumnVector.hpp"
#include "types/operations/Operation.pb.h"
#include "types/operations/binary_operations/BinaryOperation.hpp"

#include "glog/logging.h"

namespace quickstep {

ScalarBinaryExpression::ScalarBinaryExpression(const BinaryOperation &operation,
                                               Scalar *left_operand,
                                               Scalar *right_operand)
    : Scalar(*operation.resultTypeForArgumentTypes(left_operand->getType(),
                                                   right_operand->getType())),
      operation_(operation),
      left_operand_(left_operand),
      right_operand_(right_operand) {
  initHelper(false);
}

serialization::Scalar ScalarBinaryExpression::getProto() const {
  serialization::Scalar proto;
  proto.set_data_source(serialization::Scalar::BINARY_EXPRESSION);
  proto.MutableExtension(serialization::ScalarBinaryExpression::operation)->CopyFrom(operation_.getProto());
  proto.MutableExtension(serialization::ScalarBinaryExpression::left_operand)->CopyFrom(left_operand_->getProto());
  proto.MutableExtension(serialization::ScalarBinaryExpression::right_operand)->CopyFrom(right_operand_->getProto());

  return proto;
}

Scalar* ScalarBinaryExpression::clone() const {
  return new ScalarBinaryExpression(operation_,
                                    left_operand_->clone(),
                                    right_operand_->clone());
}

TypedValue ScalarBinaryExpression::getValueForSingleTuple(const ValueAccessor &accessor,
                                                          const tuple_id tuple) const {
  if (fast_operator_.get() == nullptr) {
    return static_value_.makeReferenceToThis();
  } else {
    return fast_operator_->applyToTypedValues(left_operand_->getValueForSingleTuple(accessor, tuple),
                                              right_operand_->getValueForSingleTuple(accessor, tuple));
  }
}

TypedValue ScalarBinaryExpression::getValueForJoinedTuples(
    const ValueAccessor &left_accessor,
    const relation_id left_relation_id,
    const tuple_id left_tuple_id,
    const ValueAccessor &right_accessor,
    const relation_id right_relation_id,
    const tuple_id right_tuple_id) const {
  if (fast_operator_.get() == nullptr) {
    return static_value_.makeReferenceToThis();
  } else {
    return fast_operator_->applyToTypedValues(
        left_operand_->getValueForJoinedTuples(left_accessor,
                                               left_relation_id,
                                               left_tuple_id,
                                               right_accessor,
                                               right_relation_id,
                                               right_tuple_id),
        right_operand_->getValueForJoinedTuples(left_accessor,
                                                left_relation_id,
                                                left_tuple_id,
                                                right_accessor,
                                                right_relation_id,
                                                right_tuple_id));
  }
}

ColumnVector* ScalarBinaryExpression::getAllValues(
    ValueAccessor *accessor,
    const SubBlocksReference *sub_blocks_ref) const {
  if (fast_operator_.get() == nullptr) {
    return ColumnVector::MakeVectorOfValue(getType(),
                                           static_value_,
                                           accessor->getNumTuplesVirtual());
  } else {
    // NOTE(chasseur): We don't check if BOTH operands have a static value,
    // because if they did then this expression would also have a static value
    // handled in the case above.
    if (left_operand_->hasStaticValue()) {
#ifdef QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_SELECTION
      const attribute_id right_operand_attr_id
          = right_operand_->getAttributeIdForValueAccessor();
      if (right_operand_attr_id != -1) {
        return fast_operator_->applyToStaticValueAndValueAccessor(
            left_operand_->getStaticValue(),
            accessor,
            right_operand_attr_id);
      }
#endif  // QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_SELECTION

      std::unique_ptr<ColumnVector> right_result(
          right_operand_->getAllValues(accessor, sub_blocks_ref));
      return fast_operator_->applyToStaticValueAndColumnVector(
          left_operand_->getStaticValue(),
          *right_result);
    } else if (right_operand_->hasStaticValue()) {
#ifdef QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_SELECTION
      const attribute_id left_operand_attr_id
          = left_operand_->getAttributeIdForValueAccessor();
      if (left_operand_attr_id != -1) {
        return fast_operator_->applyToValueAccessorAndStaticValue(
            accessor,
            left_operand_attr_id,
            right_operand_->getStaticValue());
      }
#endif  // QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_SELECTION

      std::unique_ptr<ColumnVector> left_result(
          left_operand_->getAllValues(accessor, sub_blocks_ref));
      return fast_operator_->applyToColumnVectorAndStaticValue(
          *left_result,
          right_operand_->getStaticValue());
    } else {
#ifdef QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_SELECTION
      const attribute_id left_operand_attr_id
          = left_operand_->getAttributeIdForValueAccessor();
      const attribute_id right_operand_attr_id
          = right_operand_->getAttributeIdForValueAccessor();

      if (left_operand_attr_id != -1) {
        if (right_operand_attr_id != -1) {
          return fast_operator_->applyToSingleValueAccessor(accessor,
                                                            left_operand_attr_id,
                                                            right_operand_attr_id);
        } else {
          std::unique_ptr<ColumnVector> right_result(
              right_operand_->getAllValues(accessor, sub_blocks_ref));
          return fast_operator_->applyToValueAccessorAndColumnVector(accessor,
                                                                     left_operand_attr_id,
                                                                     *right_result);
        }
      } else if (right_operand_attr_id != -1) {
        std::unique_ptr<ColumnVector> left_result(
            left_operand_->getAllValues(accessor, sub_blocks_ref));
        return fast_operator_->applyToColumnVectorAndValueAccessor(*left_result,
                                                                   accessor,
                                                                   right_operand_attr_id);
      }
#endif  // QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_SELECTION

      std::unique_ptr<ColumnVector> left_result(
          left_operand_->getAllValues(accessor, sub_blocks_ref));
      std::unique_ptr<ColumnVector> right_result(
          right_operand_->getAllValues(accessor, sub_blocks_ref));
      return fast_operator_->applyToColumnVectors(*left_result, *right_result);
    }
  }
}

ColumnVector* ScalarBinaryExpression::getAllValuesForJoin(
    const relation_id left_relation_id,
    ValueAccessor *left_accessor,
    const relation_id right_relation_id,
    ValueAccessor *right_accessor,
    const std::vector<std::pair<tuple_id, tuple_id>> &joined_tuple_ids) const {
  if (fast_operator_.get() == nullptr) {
    return ColumnVector::MakeVectorOfValue(getType(),
                                           static_value_,
                                           joined_tuple_ids.size());
  } else {
    if (left_operand_->hasStaticValue()) {
#ifdef QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_JOIN
      const attribute_id right_operand_attr_id
          = right_operand_->getAttributeIdForValueAccessor();
      if (right_operand_attr_id != -1) {
        const relation_id right_operand_relation_id
            = right_operand_->getRelationIdForValueAccessor();
        DCHECK_NE(right_operand_relation_id, -1);
        DCHECK((right_operand_relation_id == left_relation_id)
               || (right_operand_relation_id == right_relation_id));
        const bool using_left_relation = (right_operand_relation_id == left_relation_id);
        ValueAccessor *right_operand_accessor = using_left_relation ? left_accessor
                                                                    : right_accessor;
        return fast_operator_->applyToStaticValueAndValueAccessorForJoin(
            left_operand_->getStaticValue(),
            right_operand_accessor,
            using_left_relation,
            right_operand_attr_id,
            joined_tuple_ids);
      }
#endif  // QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_JOIN

      std::unique_ptr<ColumnVector> right_result(
          right_operand_->getAllValuesForJoin(left_relation_id,
                                              left_accessor,
                                              right_relation_id,
                                              right_accessor,
                                              joined_tuple_ids));
      return fast_operator_->applyToStaticValueAndColumnVector(
          left_operand_->getStaticValue(),
          *right_result);
    } else if (right_operand_->hasStaticValue()) {
#ifdef QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_JOIN
      const attribute_id left_operand_attr_id
          = left_operand_->getAttributeIdForValueAccessor();
      if (left_operand_attr_id != -1) {
        const relation_id left_operand_relation_id
            = left_operand_->getRelationIdForValueAccessor();
        DCHECK_NE(left_operand_relation_id, -1);
        DCHECK((left_operand_relation_id == left_relation_id)
               || (left_operand_relation_id == right_relation_id));
        const bool using_left_relation = (left_operand_relation_id == left_relation_id);
        ValueAccessor *left_operand_accessor = using_left_relation ? left_accessor
                                                                   : right_accessor;
        return fast_operator_->applyToValueAccessorAndStaticValueForJoin(
            left_operand_accessor,
            using_left_relation,
            left_operand_attr_id,
            right_operand_->getStaticValue(),
            joined_tuple_ids);
      }
#endif  // QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_JOIN

      std::unique_ptr<ColumnVector> left_result(
          left_operand_->getAllValuesForJoin(left_relation_id,
                                             left_accessor,
                                             right_relation_id,
                                             right_accessor,
                                             joined_tuple_ids));
      return fast_operator_->applyToColumnVectorAndStaticValue(
          *left_result,
          right_operand_->getStaticValue());
    } else {
#ifdef QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_JOIN
      const attribute_id left_operand_attr_id
          = left_operand_->getAttributeIdForValueAccessor();
      const attribute_id right_operand_attr_id
          = right_operand_->getAttributeIdForValueAccessor();
      if (left_operand_attr_id != -1) {
        const relation_id left_operand_relation_id
            = left_operand_->getRelationIdForValueAccessor();
        DCHECK_NE(left_operand_relation_id, -1);
        DCHECK((left_operand_relation_id == left_relation_id)
               || (left_operand_relation_id == right_relation_id));
        const bool using_left_relation_for_left_operand
            = (left_operand_relation_id == left_relation_id);
        ValueAccessor *left_operand_accessor = using_left_relation_for_left_operand ? left_accessor
                                                                                    : right_accessor;

#ifdef QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_JOIN_WITH_BINARY_EXPRESSIONS
        if (right_operand_attr_id != -1) {
          const relation_id right_operand_relation_id
              = right_operand_->getRelationIdForValueAccessor();
          DCHECK_NE(right_operand_relation_id, -1);
          DCHECK((right_operand_relation_id == left_relation_id)
                 || (right_operand_relation_id == right_relation_id));
          const bool using_left_relation_for_right_operand
              = (right_operand_relation_id == left_relation_id);
          ValueAccessor *right_operand_accessor = using_left_relation_for_right_operand ? left_accessor
                                                                                        : right_accessor;
          return fast_operator_->applyToValueAccessorsForJoin(left_operand_accessor,
                                                              using_left_relation_for_left_operand,
                                                              left_operand_attr_id,
                                                              right_operand_accessor,
                                                              using_left_relation_for_right_operand,
                                                              right_operand_attr_id,
                                                              joined_tuple_ids);
        }
#endif  // QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_JOIN_WITH_BINARY_EXPRESSIONS
        std::unique_ptr<ColumnVector> right_result(
            right_operand_->getAllValuesForJoin(left_relation_id,
                                                left_accessor,
                                                right_relation_id,
                                                right_accessor,
                                                joined_tuple_ids));

        return fast_operator_->applyToValueAccessorAndColumnVectorForJoin(
            left_operand_accessor,
            using_left_relation_for_left_operand,
            left_operand_attr_id,
            *right_result,
            joined_tuple_ids);
      } else if (right_operand_attr_id != -1) {
        const relation_id right_operand_relation_id
            = right_operand_->getRelationIdForValueAccessor();
        DCHECK_NE(right_operand_relation_id, -1);
        DCHECK((right_operand_relation_id == left_relation_id)
               || (right_operand_relation_id == right_relation_id));
        const bool using_left_relation_for_right_operand
            = (right_operand_relation_id == left_relation_id);
        ValueAccessor *right_operand_accessor = using_left_relation_for_right_operand ? left_accessor
                                                                                      : right_accessor;

        std::unique_ptr<ColumnVector> left_result(
            left_operand_->getAllValuesForJoin(left_relation_id,
                                               left_accessor,
                                               right_relation_id,
                                               right_accessor,
                                               joined_tuple_ids));
        return fast_operator_->applyToColumnVectorAndValueAccessorForJoin(
            *left_result,
            right_operand_accessor,
            using_left_relation_for_right_operand,
            right_operand_attr_id,
            joined_tuple_ids);
      }
#endif  // QUICKSTEP_ENABLE_VECTOR_COPY_ELISION_JOIN

      std::unique_ptr<ColumnVector> left_result(
          left_operand_->getAllValuesForJoin(left_relation_id,
                                             left_accessor,
                                             right_relation_id,
                                             right_accessor,
                                             joined_tuple_ids));
      std::unique_ptr<ColumnVector> right_result(
          right_operand_->getAllValuesForJoin(left_relation_id,
                                              left_accessor,
                                              right_relation_id,
                                              right_accessor,
                                              joined_tuple_ids));
      return fast_operator_->applyToColumnVectors(*left_result, *right_result);
    }
  }
}

void ScalarBinaryExpression::initHelper(bool own_children) {
  if (operation_.canApplyToTypes(left_operand_->getType(), right_operand_->getType())) {
    if (left_operand_->hasStaticValue() && right_operand_->hasStaticValue()) {
      static_value_ = operation_.applyToChecked(left_operand_->getStaticValue(),
                                                left_operand_->getType(),
                                                right_operand_->getStaticValue(),
                                                right_operand_->getType());
    } else {
      fast_operator_.reset(operation_.makeUncheckedBinaryOperatorForTypes(left_operand_->getType(),
                                                                           right_operand_->getType()));
    }
  } else {
    const Type &left_operand_type = left_operand_->getType();
    const Type &right_operand_type = right_operand_->getType();
    if (!own_children) {
      left_operand_.release();
      right_operand_.release();
    }
    throw OperationInapplicableToType(operation_.getName(),
                                      2,
                                      left_operand_type.getName().c_str(),
                                      right_operand_type.getName().c_str());
  }
}

}  // namespace quickstep