// 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 "runtime/buffer_control_block.h"

#include <gen_cpp/Data_types.h>
#include <gen_cpp/PaloInternalService_types.h>
#include <gen_cpp/internal_service.pb.h>
#include <glog/logging.h>
#include <google/protobuf/stubs/callback.h>
// IWYU pragma: no_include <bits/chrono.h>
#include <chrono> // IWYU pragma: keep
#include <ostream>
#include <string>
#include <utility>
#include <vector>

#include "runtime/exec_env.h"
#include "runtime/thread_context.h"
#include "util/thrift_util.h"

namespace doris {

void GetResultBatchCtx::on_failure(const Status& status) {
    DCHECK(!status.ok()) << "status is ok, errmsg=" << status;
    status.to_protobuf(result->mutable_status());
    {
        // call by result sink
        SCOPED_SWITCH_THREAD_MEM_TRACKER_LIMITER(ExecEnv::GetInstance()->orphan_mem_tracker());
        done->Run();
    }
    delete this;
}

void GetResultBatchCtx::on_close(int64_t packet_seq, QueryStatistics* statistics) {
    Status status;
    status.to_protobuf(result->mutable_status());
    if (statistics != nullptr) {
        statistics->to_pb(result->mutable_query_statistics());
    }
    result->set_packet_seq(packet_seq);
    result->set_eos(true);
    {
        SCOPED_SWITCH_THREAD_MEM_TRACKER_LIMITER(ExecEnv::GetInstance()->orphan_mem_tracker());
        done->Run();
    }
    delete this;
}

void GetResultBatchCtx::on_data(const std::unique_ptr<TFetchDataResult>& t_result,
                                int64_t packet_seq, bool eos) {
    Status st = Status::OK();
    if (t_result != nullptr) {
        uint8_t* buf = nullptr;
        uint32_t len = 0;
        ThriftSerializer ser(false, 4096);
        st = ser.serialize(&t_result->result_batch, &len, &buf);
        if (st.ok()) {
            result->set_row_batch(std::string((const char*)buf, len));
            result->set_packet_seq(packet_seq);
            result->set_eos(eos);
        } else {
            LOG(WARNING) << "TFetchDataResult serialize failed, errmsg=" << st;
        }
    } else {
        result->set_empty_batch(true);
        result->set_packet_seq(packet_seq);
        result->set_eos(eos);
    }
    st.to_protobuf(result->mutable_status());
    {
        SCOPED_SWITCH_THREAD_MEM_TRACKER_LIMITER(ExecEnv::GetInstance()->orphan_mem_tracker());
        done->Run();
    }
    delete this;
}

BufferControlBlock::BufferControlBlock(const TUniqueId& id, int buffer_size)
        : _fragment_id(id),
          _is_close(false),
          _is_cancelled(false),
          _buffer_rows(0),
          _buffer_limit(buffer_size),
          _packet_num(0) {}

BufferControlBlock::~BufferControlBlock() {
    cancel();
}

Status BufferControlBlock::init() {
    return Status::OK();
}

bool BufferControlBlock::can_sink() {
    std::unique_lock<std::mutex> l(_lock);
    return _get_batch_queue_empty() || _buffer_rows < _buffer_limit || _is_cancelled;
}

Status BufferControlBlock::add_batch(std::unique_ptr<TFetchDataResult>& result) {
    std::unique_lock<std::mutex> l(_lock);

    if (_is_cancelled) {
        return Status::Cancelled("Cancelled");
    }

    int num_rows = result->result_batch.rows.size();

    while ((!_batch_queue.empty() && _buffer_rows > _buffer_limit) && !_is_cancelled) {
        _data_removal.wait_for(l, std::chrono::seconds(1));
    }

    if (_is_cancelled) {
        return Status::Cancelled("Cancelled");
    }

    if (_waiting_rpc.empty()) {
        // Merge result into batch to reduce rpc times
        if (!_batch_queue.empty() &&
            ((_batch_queue.back()->result_batch.rows.size() + num_rows) < _buffer_limit) &&
            !result->eos) {
            std::vector<std::string>& back_rows = _batch_queue.back()->result_batch.rows;
            std::vector<std::string>& result_rows = result->result_batch.rows;
            back_rows.insert(back_rows.end(), std::make_move_iterator(result_rows.begin()),
                             std::make_move_iterator(result_rows.end()));
        } else {
            _batch_queue.push_back(std::move(result));
        }
        _buffer_rows += num_rows;
        _data_arrival.notify_one();
    } else {
        auto ctx = _waiting_rpc.front();
        _waiting_rpc.pop_front();
        ctx->on_data(result, _packet_num);
        _packet_num++;
    }
    return Status::OK();
}

void BufferControlBlock::get_batch(GetResultBatchCtx* ctx) {
    std::lock_guard<std::mutex> l(_lock);
    if (!_status.ok()) {
        ctx->on_failure(_status);
        return;
    }
    if (_is_cancelled) {
        ctx->on_failure(Status::Cancelled("Cancelled"));
        return;
    }
    if (!_batch_queue.empty()) {
        // get result
        std::unique_ptr<TFetchDataResult> result = std::move(_batch_queue.front());
        _batch_queue.pop_front();
        _buffer_rows -= result->result_batch.rows.size();
        _data_removal.notify_one();

        ctx->on_data(result, _packet_num);
        _packet_num++;
        return;
    }
    if (_is_close) {
        ctx->on_close(_packet_num, _query_statistics.get());
        return;
    }
    // no ready data, push ctx to waiting list
    _waiting_rpc.push_back(ctx);
}

Status BufferControlBlock::close(Status exec_status) {
    std::unique_lock<std::mutex> l(_lock);
    _is_close = true;
    _status = exec_status;

    // notify blocked get thread
    _data_arrival.notify_all();
    if (!_waiting_rpc.empty()) {
        if (_status.ok()) {
            for (auto& ctx : _waiting_rpc) {
                ctx->on_close(_packet_num, _query_statistics.get());
            }
        } else {
            for (auto& ctx : _waiting_rpc) {
                ctx->on_failure(_status);
            }
        }
        _waiting_rpc.clear();
    }
    return Status::OK();
}

Status BufferControlBlock::cancel() {
    std::unique_lock<std::mutex> l(_lock);
    _is_cancelled = true;
    _data_removal.notify_all();
    _data_arrival.notify_all();
    for (auto& ctx : _waiting_rpc) {
        ctx->on_failure(Status::Cancelled("Cancelled"));
    }
    _waiting_rpc.clear();
    return Status::OK();
}

} // namespace doris