// 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.

#include <DataStreams/OwningBlockInputStream.h>
#include <Dictionaries/FileDictionarySource.h>
#include <IO/Buffer/ReadBufferFromFile.h>
#include <Interpreters/Context.h>
#include <Poco/File.h>


namespace DB
{

static const size_t max_block_size = 8192;


FileDictionarySource::FileDictionarySource(
    const std::string & filename,
    const std::string & format,
    Block & sample_block,
    const Context & context)
    : filename{filename}
    , format{format}
    , sample_block{sample_block}
    , context(context)
{}


FileDictionarySource::FileDictionarySource(const FileDictionarySource & other)
    : filename{other.filename}
    , format{other.format}
    , sample_block{other.sample_block}
    , context(other.context)
    , last_modification{other.last_modification}
{}


BlockInputStreamPtr FileDictionarySource::loadAll()
{
    auto in_ptr = std::make_unique<ReadBufferFromFile>(filename);
    auto stream = context.getInputFormat(format, *in_ptr, sample_block, max_block_size);
    last_modification = getLastModification();

    return std::make_shared<OwningBlockInputStream<ReadBuffer>>(stream, std::move(in_ptr));
}


std::string FileDictionarySource::toString() const
{
    return "File: " + filename + ' ' + format;
}


Poco::Timestamp FileDictionarySource::getLastModification() const
{
    return Poco::File{filename}.getLastModified();
}

} // namespace DB