// 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.

#pragma once

#include <cstdint>

#include "exec/exchange/vdata_stream_sender.h"

#include "exec/partitioner/partitioner.h"

namespace doris {

class RuntimeState;

class Status;

class Block;

class Channel;

class PartitionerBase;

class TabletSinkHashPartitioner;

class ExchangeSinkLocalState;

class ExchangeWriterBase {

public:

    using HashValType = PartitionerBase::HashValType;

    ExchangeWriterBase(ExchangeSinkLocalState& local_state);

    virtual Status write(RuntimeState* state, Block* block, bool eos) = 0;

    virtual ~ExchangeWriterBase() = default;

protected:

    template <typename ChannelPtrType>

    Status _handle_eof_channel(RuntimeState* state, ChannelPtrType channel, Status st) const;

    Status _add_rows_impl(RuntimeState* state, std::vector<std::shared_ptr<Channel>>& channels,

                          size_t channel_count, Block* block, bool eos);

    // myself as a visitor of local state

    ExchangeSinkLocalState& _local_state;

    PartitionerBase* _partitioner;

    // _origin_row_idx[i]: row id in original block for the i-th's data we send.

    PaddedPODArray<uint32_t> _origin_row_idx;

    // _channel_rows_histogram[i]: number of rows for channel i in current batch

    PaddedPODArray<uint32_t> _channel_rows_histogram;

    // _channel_start_offsets[i]: the start offset of channel i in _row_idx

    // its value equals to prefix sum of _channel_rows_histogram

    // after calculation, it will be end offset for channel i.

    PaddedPODArray<uint32_t> _channel_pos_offsets;

};

class ExchangeTrivialWriter final : public ExchangeWriterBase {

public:

    ExchangeTrivialWriter(ExchangeSinkLocalState& local_state) : ExchangeWriterBase(local_state) {}

    Status write(RuntimeState* state, Block* block, bool eos) override;

private:

    Status _channel_add_rows(RuntimeState* state, std::vector<std::shared_ptr<Channel>>& channels,

                             size_t channel_count, const std::vector<HashValType>& channel_ids,

                             size_t rows, Block* block, bool eos);

};

// maybe auto partition

class ExchangeOlapWriter final : public ExchangeWriterBase {

public:

    ExchangeOlapWriter(ExchangeSinkLocalState& local_state) : ExchangeWriterBase(local_state) {}

    Status write(RuntimeState* state, Block* block, bool eos) override;

private:

    Status _write_impl(RuntimeState* state, Block* block, bool eos = false);

    Status _channel_add_rows(RuntimeState* state, std::vector<std::shared_ptr<Channel>>& channels,

                             size_t channel_count, const std::vector<HashValType>& channel_ids,

                             size_t rows, Block* block, bool eos, HashValType invalid_val);

};

} // namespace doris