/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you 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/ScalarAttribute.hpp"

#include <utility>
#include <vector>

#include "catalog/CatalogAttribute.hpp"
#include "catalog/CatalogRelationSchema.hpp"
#include "catalog/CatalogTypedefs.hpp"
#include "expressions/Expressions.pb.h"
#include "storage/StorageBlockInfo.hpp"
#include "storage/ValueAccessor.hpp"
#include "storage/ValueAccessorUtil.hpp"
#include "types/Type.hpp"
#include "types/TypedValue.hpp"
#include "types/containers/ColumnVector.hpp"
#include "utility/Macros.hpp"

#include "glog/logging.h"

namespace quickstep {

ScalarAttribute::ScalarAttribute(const CatalogAttribute &attribute)
    : Scalar(attribute.getType()),
      attribute_(attribute) {
}

serialization::Scalar ScalarAttribute::getProto() const {
  serialization::Scalar proto;
  proto.set_data_source(serialization::Scalar::ATTRIBUTE);
  proto.SetExtension(serialization::ScalarAttribute::relation_id, attribute_.getParent().getID());
  proto.SetExtension(serialization::ScalarAttribute::attribute_id, attribute_.getID());

  return proto;
}

Scalar* ScalarAttribute::clone() const {
  return new ScalarAttribute(attribute_);
}

TypedValue ScalarAttribute::getValueForSingleTuple(const ValueAccessor &accessor,
                                                   const tuple_id tuple) const {
  return accessor.getTypedValueAtAbsolutePositionVirtual(attribute_.getID(), tuple);
}

TypedValue ScalarAttribute::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 {
  // FIXME(chasseur): This can get confused and break for self-joins.
  DCHECK((attribute_.getParent().getID() == left_relation_id)
         || (attribute_.getParent().getID() == right_relation_id));
  if (attribute_.getParent().getID() == left_relation_id) {
    return left_accessor.getTypedValueAtAbsolutePositionVirtual(attribute_.getID(),
                                                                left_tuple_id);
  } else {
    return right_accessor.getTypedValueAtAbsolutePositionVirtual(attribute_.getID(),
                                                                 right_tuple_id);
  }
}

attribute_id ScalarAttribute::getAttributeIdForValueAccessor() const {
  return attribute_.getID();
}

relation_id ScalarAttribute::getRelationIdForValueAccessor() const {
  return attribute_.getParent().getID();
}

ColumnVector* ScalarAttribute::getAllValues(ValueAccessor *accessor,
                                            const SubBlocksReference *sub_blocks_ref) const {
  const attribute_id attr_id = attribute_.getID();
  const Type &result_type = attribute_.getType();
  return InvokeOnValueAccessorMaybeTupleIdSequenceAdapter(
      accessor,
      [&attr_id, &result_type](auto *accessor) -> ColumnVector* {  // NOLINT(build/c++11)
    if (NativeColumnVector::UsableForType(result_type)) {
      NativeColumnVector *result = new NativeColumnVector(result_type,
                                                          accessor->getNumTuples());
      accessor->beginIteration();
      if (result_type.isNullable()) {
        if (accessor->isColumnAccessorSupported()) {
          // If ColumnAccessor is supported on the underlying accessor, we have a fast strided
          // column accessor available for the iteration on the underlying block.
          // Since the attributes can be null, ColumnAccessor template takes a 'true' argument.
          std::unique_ptr<const ColumnAccessor<true>>
              column_accessor(accessor->template getColumnAccessor<true>(attr_id));
          while (accessor->next()) {
            const void *value = column_accessor->getUntypedValue();  // Fast strided access.
            if (value == nullptr) {
              result->appendNullValue();
            } else {
              result->appendUntypedValue(value);
            }
          }
        } else {
          while (accessor->next()) {
            const void *value = accessor->template getUntypedValue<true>(attr_id);
            if (value == nullptr) {
              result->appendNullValue();
            } else {
              result->appendUntypedValue(value);
            }
          }
        }
      } else {
        if (accessor->isColumnAccessorSupported()) {
          // Since the attributes cannot be null, ColumnAccessor template takes a 'false' argument.
          std::unique_ptr<const ColumnAccessor<false>>
              column_accessor(accessor->template getColumnAccessor<false>(attr_id));
          while (accessor->next()) {
            result->appendUntypedValue(column_accessor->getUntypedValue());  // Fast strided access.
          }
        } else {
          while (accessor->next()) {
            result->appendUntypedValue(
                accessor->template getUntypedValue<false>(attr_id));
          }
        }
      }
      return result;
    } else {
      IndirectColumnVector *result = new IndirectColumnVector(result_type,
                                                              accessor->getNumTuples());
      accessor->beginIteration();
      while (accessor->next()) {
        result->appendTypedValue(accessor->getTypedValue(attr_id));
      }
      return result;
    }
  });
}

ColumnVector* ScalarAttribute::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 {
  DCHECK((attribute_.getParent().getID() == left_relation_id)
         || (attribute_.getParent().getID() == right_relation_id));

  const attribute_id attr_id = attribute_.getID();
  const Type &result_type = attribute_.getType();

  const bool using_left_relation = (attribute_.getParent().getID() == left_relation_id);
  ValueAccessor *accessor = using_left_relation ? left_accessor
                                                : right_accessor;

  return InvokeOnAnyValueAccessor(
      accessor,
      [&joined_tuple_ids,
       &attr_id,
       &result_type,
       &using_left_relation](auto *accessor) -> ColumnVector* {  // NOLINT(build/c++11)
    if (NativeColumnVector::UsableForType(result_type)) {
      NativeColumnVector *result = new NativeColumnVector(result_type,
                                                          joined_tuple_ids.size());
      if (result_type.isNullable()) {
        for (const std::pair<tuple_id, tuple_id> &joined_pair : joined_tuple_ids) {
          const void *value = accessor->template getUntypedValueAtAbsolutePosition<true>(
              attr_id,
              using_left_relation ? joined_pair.first : joined_pair.second);
          if (value == nullptr) {
            result->appendNullValue();
          } else {
            result->appendUntypedValue(value);
          }
        }
      } else {
        for (const std::pair<tuple_id, tuple_id> &joined_pair : joined_tuple_ids) {
          result->appendUntypedValue(
              accessor->template getUntypedValueAtAbsolutePosition<false>(
                  attr_id,
                  using_left_relation ? joined_pair.first : joined_pair.second));
        }
      }
      return result;
    } else {
      IndirectColumnVector *result = new IndirectColumnVector(result_type,
                                                              joined_tuple_ids.size());
      for (const std::pair<tuple_id, tuple_id> &joined_pair : joined_tuple_ids) {
        result->appendTypedValue(
              accessor->getTypedValueAtAbsolutePosition(
                  attr_id,
                  using_left_relation ? joined_pair.first : joined_pair.second));
      }
      return result;
    }
  });
}

}  // namespace quickstep