/*
 * 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 <memory>
#include <vector>

#include "paimon/reader/count_reader.h"
#include "paimon/result.h"

namespace arrow {
class Schema;
}  // namespace arrow

namespace paimon {
class DataSplitImpl;
class Executor;
class FileStorePathFactory;
class InternalReadContext;
class MemoryPool;
class MergeFileSplitRead;
class Split;

class PKCountReader : public CountReader {
 public:
    ~PKCountReader() override;

    static Result<std::unique_ptr<PKCountReader>> Create(
        std::vector<std::shared_ptr<Split>> splits,
        const std::shared_ptr<FileStorePathFactory>& path_factory,
        const std::shared_ptr<InternalReadContext>& context,
        const std::shared_ptr<MemoryPool>& memory_pool, const std::shared_ptr<Executor>& executor);

    Result<int64_t> CountRows() override;

 private:
    PKCountReader(std::vector<std::shared_ptr<Split>> splits,
                  const std::shared_ptr<InternalReadContext>& context,
                  std::unique_ptr<MergeFileSplitRead>&& merge_read,
                  const std::shared_ptr<MemoryPool>& memory_pool);

    Result<int64_t> CountSingleSplit(const std::shared_ptr<Split>& split);
    Result<int64_t> MetadataCount(const std::shared_ptr<DataSplitImpl>& split);
    Result<int64_t> MergeCount(const std::shared_ptr<DataSplitImpl>& split);

 private:
    std::vector<std::shared_ptr<Split>> splits_;
    std::shared_ptr<InternalReadContext> context_;
    std::unique_ptr<MergeFileSplitRead> merge_read_;
    std::shared_ptr<MemoryPool> pool_;
};

}  // namespace paimon
