// Copyright 2023 PingCAP, 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 <AggregateFunctions/AggregateFunctionFactory.h>
#include <AggregateFunctions/AggregateFunctionGroupUniqArray.h>
#include <AggregateFunctions/FactoryHelpers.h>
#include <AggregateFunctions/Helpers.h>
#include <DataTypes/DataTypeDate.h>
#include <DataTypes/DataTypeDateTime.h>


namespace DB
{
namespace
{
/// Substitute return type for Date and DateTime
class AggregateFunctionGroupUniqArrayDate : public AggregateFunctionGroupUniqArray<DataTypeDate::FieldType>
{
    DataTypePtr getReturnType() const override
    {
        return std::make_shared<DataTypeArray>(std::make_shared<DataTypeDate>());
    }
};

class AggregateFunctionGroupUniqArrayDateTime : public AggregateFunctionGroupUniqArray<DataTypeDateTime::FieldType>
{
    DataTypePtr getReturnType() const override
    {
        return std::make_shared<DataTypeArray>(std::make_shared<DataTypeDateTime>());
    }
};

IAggregateFunction * createWithExtraTypes(const DataTypePtr & argument_type)
{
    if (typeid_cast<const DataTypeDate *>(argument_type.get()))
        return new AggregateFunctionGroupUniqArrayDate;
    else if (typeid_cast<const DataTypeDateTime *>(argument_type.get()))
        return new AggregateFunctionGroupUniqArrayDateTime;
    else
    {
        /// Check that we can use plain version of AggregateFunctionGroupUniqArrayGeneric
        if (argument_type->isValueUnambiguouslyRepresentedInContiguousMemoryRegion())
            return new AggregateFunctionGroupUniqArrayGeneric<true>(argument_type);
        else
            return new AggregateFunctionGroupUniqArrayGeneric<false>(argument_type);
    }
}

AggregateFunctionPtr createAggregateFunctionGroupUniqArray(
    const Context & /* context not used */,
    const std::string & name,
    const DataTypes & argument_types,
    const Array & parameters)
{
    assertNoParameters(name, parameters);
    assertUnary(name, argument_types);

    AggregateFunctionPtr res(createWithNumericType<AggregateFunctionGroupUniqArray>(*argument_types[0]));

    if (!res)
        res = AggregateFunctionPtr(createWithExtraTypes(argument_types[0]));

    if (!res)
        throw Exception(
            "Illegal type " + argument_types[0]->getName() + " of argument for aggregate function " + name,
            ErrorCodes::ILLEGAL_TYPE_OF_ARGUMENT);

    return res;
}

} // namespace

void registerAggregateFunctionGroupUniqArray(AggregateFunctionFactory & factory)
{
    factory.registerFunction("groupUniqArray", createAggregateFunctionGroupUniqArray);
}

} // namespace DB