/**
 * 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/aggregation/AggregateFunctionFactory.hpp"

#include <string>
#include <type_traits>

#include "expressions/aggregation/AggregateFunction.pb.h"
#include "expressions/aggregation/AggregateFunctionAvg.hpp"
#include "expressions/aggregation/AggregateFunctionCount.hpp"
#include "expressions/aggregation/AggregateFunctionMax.hpp"
#include "expressions/aggregation/AggregateFunctionMin.hpp"
#include "expressions/aggregation/AggregateFunctionSum.hpp"
#include "expressions/aggregation/AggregationID.hpp"

#include "glog/logging.h"

namespace quickstep {

const AggregateFunction& AggregateFunctionFactory::Get(
    const AggregationID agg_id) {
  switch (agg_id) {
    case AggregationID::kAvg:
      return AggregateFunctionAvg::Instance();
    case AggregationID::kCount:
      return AggregateFunctionCount::Instance();
    case AggregationID::kMax:
      return AggregateFunctionMax::Instance();
    case AggregationID::kMin:
      return AggregateFunctionMin::Instance();
    case AggregationID::kSum:
      return AggregateFunctionSum::Instance();
    default: {
      LOG(FATAL) << "Unrecognized AggregationID: "
                 << static_cast<std::underlying_type<AggregationID>::type>(agg_id);
    }
  }
}

const AggregateFunction* AggregateFunctionFactory::GetByName(const std::string &name) {
  if (name == "avg") {
    return &AggregateFunctionAvg::Instance();
  } else if (name == "count") {
    return &AggregateFunctionCount::Instance();
  } else if (name == "max") {
    return &AggregateFunctionMax::Instance();
  } else if (name == "min") {
    return &AggregateFunctionMin::Instance();
  } else if (name == "sum") {
    return &AggregateFunctionSum::Instance();
  } else {
    return nullptr;
  }
}

bool AggregateFunctionFactory::ProtoIsValid(
    const serialization::AggregateFunction &proto) {
  return proto.IsInitialized()
         && serialization::AggregateFunction::AggregationID_IsValid(proto.aggregation_id());
}

const AggregateFunction& AggregateFunctionFactory::ReconstructFromProto(
    const serialization::AggregateFunction &proto) {
  DCHECK(ProtoIsValid(proto))
      << "Attempted to reconstruct an AggregateFunction from an invalid proto:\n"
      << proto.DebugString();

  switch (proto.aggregation_id()) {
    case serialization::AggregateFunction::AVG:
      return AggregateFunctionAvg::Instance();
    case serialization::AggregateFunction::COUNT:
      return AggregateFunctionCount::Instance();
    case serialization::AggregateFunction::MAX:
      return AggregateFunctionMax::Instance();
    case serialization::AggregateFunction::MIN:
      return AggregateFunctionMin::Instance();
    case serialization::AggregateFunction::SUM:
      return AggregateFunctionSum::Instance();
    default: {
      LOG(FATAL) << "Unrecognized serialization::AggregateFunction::AggregationID: "
                 << proto.aggregation_id()
                 << "\nFull proto debug string:\n"
                 << proto.DebugString();
    }
  }
}

}  // namespace quickstep