// 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 "format/table/table_format_reader.h"

#include "load/group_commit/wal/wal_file_reader.h"

#include "runtime/descriptors.h"

namespace doris {

struct ScannerCounter;

/// WAL-specific initialization context.

/// Extends ReaderInitContext with output tuple descriptor (unique to WAL reader).

struct WalInitContext final : public ReaderInitContext {

    const TupleDescriptor* output_tuple_descriptor = nullptr;

};

class WalReader : public TableFormatReader {

    ENABLE_FACTORY_CREATOR(WalReader);

public:

    WalReader(RuntimeState* state);

    ~WalReader() override = default;

    Status init_reader(const TupleDescriptor* tuple_descriptor);

    Status _do_get_next_block(Block* block, size_t* read_rows, bool* eof) override;

    Status _get_columns_impl(std::unordered_map<std::string, DataTypePtr>* name_to_type) override;

    Status close() override {

        if (_wal_reader) {

            return _wal_reader->finalize();

        }

        return Status::OK();

    }

protected:

    // ---- Unified init_reader(ReaderInitContext*) overrides ----

    Status _open_file_reader(ReaderInitContext* ctx) override;

    Status _do_init_reader(ReaderInitContext* ctx) override;

private:

    RuntimeState* _state = nullptr;

    int64_t _wal_id;

    std::string _wal_path;

    std::shared_ptr<doris::WalFileReader> _wal_reader = nullptr;

    const TupleDescriptor* _tuple_descriptor = nullptr;

    // column_id, column_pos

    std::map<int64_t, int64_t> _column_pos_map;

    int64_t _column_id_count;

    uint32_t _version = 0;

};

} // namespace doris