// Copyright 2023 PingCAP, Inc.
//
// Licensed 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 <Core/Block.h>
#include <DataStreams/IRowInputStream.h>


namespace DB
{

class ReadBuffer;


/** A stream to input data in tsv format.
  */
class TabSeparatedRowInputStream : public IRowInputStream
{
public:
    /** with_names - the first line is the header with the names of the columns
      * with_types - on the next line header with type names
      */
    TabSeparatedRowInputStream(
        ReadBuffer & istr_,
        const Block & header_,
        bool with_names_ = false,
        bool with_types_ = false);

    bool read(MutableColumns & columns) override;
    void readPrefix() override;
    bool allowSyncAfterError() const override { return true; }
    void syncAfterError() override;

    std::string getDiagnosticInfo() override;

private:
    ReadBuffer & istr;
    Block header;
    bool with_names;
    bool with_types;
    DataTypes data_types;

    /// For convenient diagnostics in case of an error.

    size_t row_num = 0;

    /// How many bytes were read, not counting those still in the buffer.
    size_t bytes_read_at_start_of_buffer_on_current_row = 0;
    size_t bytes_read_at_start_of_buffer_on_prev_row = 0;

    char * pos_of_current_row = nullptr;
    char * pos_of_prev_row = nullptr;

    void updateDiagnosticInfo();

    bool parseRowAndPrintDiagnosticInfo(
        MutableColumns & columns,
        WriteBuffer & out,
        size_t max_length_of_column_name,
        size_t max_length_of_data_type_name);
};

} // namespace DB