// 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 "exec/exchange/exchange_writer.h"

#include <glog/logging.h>

#include <algorithm>

#include <cstdint>

#include <vector>

#include "common/logging.h"

#include "common/status.h"

#include "core/assert_cast.h"

#include "core/block/block.h"

#include "exec/operator/exchange_sink_operator.h"

#include "exec/sink/tablet_sink_hash_partitioner.h"

namespace doris {

ExchangeWriterBase::ExchangeWriterBase(ExchangeSinkLocalState& local_state)

        : _local_state(local_state), _partitioner(local_state.partitioner()) {}

template <typename ChannelPtrType>

Status ExchangeWriterBase::_handle_eof_channel(RuntimeState* state, ChannelPtrType channel,

                                               Status st) const {

    channel->set_receiver_eof(st);

    // Channel will not send RPC to the downstream when eof, so close channel by OK status.

    return channel->close(state);

}

// NOLINTBEGIN(readability-function-cognitive-complexity)

Status ExchangeWriterBase::_add_rows_impl(RuntimeState* state,

                                          std::vector<std::shared_ptr<Channel>>& channels,

                                          size_t channel_count, Block* block, bool eos) {

    Status status = Status::OK();

    uint32_t offset = 0;

    for (size_t i = 0; i < channel_count; ++i) {

        uint32_t size = _channel_rows_histogram[i];

        if (!channels[i]->is_receiver_eof() && size > 0) {

            VLOG_DEBUG << fmt::format("partition {} of {}, block:\n{}, start: {}, size: {}", i,

                                      channel_count, block->dump_data(), offset, size);

            status = channels[i]->add_rows(block, _origin_row_idx.data(), offset, size, false);

            HANDLE_CHANNEL_STATUS(state, channels[i], status);

        }

        offset += size;

    }

    if (eos) {

        for (int i = 0; i < channel_count; ++i) {

            if (!channels[i]->is_receiver_eof()) {

                VLOG_DEBUG << fmt::format("EOS partition {} of {}, block:\n{}", i, channel_count,

                                          block->dump_data());

                status = channels[i]->add_rows(block, _origin_row_idx.data(), 0, 0, true);

                HANDLE_CHANNEL_STATUS(state, channels[i], status);

            }

        }

    }

    return Status::OK();

}

// NOLINTEND(readability-function-cognitive-complexity)

Status ExchangeOlapWriter::write(RuntimeState* state, Block* block, bool eos) {

    Block prior_block;

    auto* tablet_partitioner = assert_cast<TabletSinkHashPartitioner*>(_partitioner);

    RETURN_IF_ERROR(tablet_partitioner->try_cut_in_line(prior_block));

    if (!prior_block.empty()) {

        // prior_block (batching rows) cuts in line, deal it first.

        RETURN_IF_ERROR(_write_impl(state, &prior_block));

        tablet_partitioner->finish_cut_in_line();

    }

    RETURN_IF_ERROR(_write_impl(state, block));

    // all data wrote. consider batched rows before eos.

    if (eos) {

        // get all batched rows

        tablet_partitioner->mark_last_block();

        Block final_batching_block;

        RETURN_IF_ERROR(tablet_partitioner->try_cut_in_line(final_batching_block));

        if (!final_batching_block.empty()) {

            RETURN_IF_ERROR(_write_impl(state, &final_batching_block, true));

        } else {

            // No batched rows, send empty block with eos signal.

            Block empty_block = block->clone_empty();

            RETURN_IF_ERROR(_write_impl(state, &empty_block, true));

        }

    }

    return Status::OK();

}

Status ExchangeOlapWriter::_write_impl(RuntimeState* state, Block* block, bool eos) {

    auto rows = block->rows();

    auto* tablet_partitioner = assert_cast<TabletSinkHashPartitioner*>(_partitioner);

    {

        SCOPED_TIMER(_local_state.split_block_hash_compute_timer());

        RETURN_IF_ERROR(tablet_partitioner->do_partitioning(state, block));

    }

    {

        SCOPED_TIMER(_local_state.distribute_rows_into_channels_timer());

        const auto& channel_ids = tablet_partitioner->get_channel_ids();

        const auto invalid_val = tablet_partitioner->invalid_sentinel();

        DCHECK_EQ(channel_ids.size(), rows);

        // decrease not sinked rows this time

        COUNTER_UPDATE(_local_state.rows_input_counter(),

                       -1LL * std::ranges::count(channel_ids, invalid_val));

        RETURN_IF_ERROR(_channel_add_rows(state, _local_state.channels,

                                          _local_state.channels.size(), channel_ids, rows, block,

                                          eos, invalid_val));

    }

    return Status::OK();

}

Status ExchangeTrivialWriter::write(RuntimeState* state, Block* block, bool eos) {

    {

        SCOPED_TIMER(_local_state.split_block_hash_compute_timer());

        RETURN_IF_ERROR(_partitioner->do_partitioning(state, block));

    }

    {

        auto rows = block->rows();

        SCOPED_TIMER(_local_state.distribute_rows_into_channels_timer());

        const auto& channel_ids = _partitioner->get_channel_ids();

        RETURN_IF_ERROR(_channel_add_rows(state, _local_state.channels,

                                          _local_state.channels.size(), channel_ids, rows, block,

                                          eos));

    }

    return Status::OK();

}

Status ExchangeOlapWriter::_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) {

    size_t effective_rows = 0;

    effective_rows =

            std::ranges::count_if(channel_ids, [=](int64_t cid) { return cid != invalid_val; });

    // row index will skip all skipped rows.

    _origin_row_idx.resize(effective_rows);

    _channel_rows_histogram.assign(channel_count, 0U);

    _channel_pos_offsets.resize(channel_count);

    for (size_t i = 0; i < rows; ++i) {

        if (channel_ids[i] == invalid_val) {

            continue;

        }

        auto cid = channel_ids[i];

        _channel_rows_histogram[cid]++;

    }

    _channel_pos_offsets[0] = 0;

    for (size_t i = 1; i < channel_count; ++i) {

        _channel_pos_offsets[i] = _channel_pos_offsets[i - 1] + _channel_rows_histogram[i - 1];

    }

    for (uint32_t i = 0; i < rows; ++i) {

        if (channel_ids[i] == invalid_val) {

            continue;

        }

        auto cid = channel_ids[i];

        auto pos = _channel_pos_offsets[cid]++;

        _origin_row_idx[pos] = i;

    }

    return _add_rows_impl(state, channels, channel_count, block, eos);

}

Status ExchangeTrivialWriter::_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) {

    _origin_row_idx.resize(rows);

    _channel_rows_histogram.assign(channel_count, 0U);

    _channel_pos_offsets.resize(channel_count);

    for (size_t i = 0; i < rows; ++i) {

        _channel_rows_histogram[channel_ids[i]]++;

    }

    _channel_pos_offsets[0] = 0;

    for (size_t i = 1; i < channel_count; ++i) {

        _channel_pos_offsets[i] = _channel_pos_offsets[i - 1] + _channel_rows_histogram[i - 1];

    }

    for (uint32_t i = 0; i < rows; i++) {

        auto cid = channel_ids[i];

        auto pos = _channel_pos_offsets[cid]++;

        _origin_row_idx[pos] = i;

    }

    return _add_rows_impl(state, channels, channel_count, block, eos);

}

} // namespace doris