/*

  Copyright © 2020 Hasan Yavuz Özderya

  This file is part of serialplot.

  serialplot is free software: you can redistribute it and/or modify

  it under the terms of the GNU General Public License as published by

  the Free Software Foundation, either version 3 of the License, or

  (at your option) any later version.

  serialplot is distributed in the hope that it will be useful,

  but WITHOUT ANY WARRANTY; without even the implied warranty of

  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License

  along with serialplot.  If not, see <http://www.gnu.org/licenses/>.

*/

#include "chunkedbuffer.h"

ChunkedBuffer::ChunkedBuffer()

{

    numChunks = 0;

    _size = 0;

    // create first chunk

    addNewChunk();

}

ChunkedBuffer::~ChunkedBuffer()

{

    for (auto chunk : chunks)

    {

        delete chunk;

    }

}

void ChunkedBuffer::addSamples(double* samples, unsigned n)

{

    size_t i = 0;

    while (i < n)

    {

        // select chunk to add data

        auto chunk = chunks.last();

        if (chunk->isFull())

        {

            chunk = addNewChunk(); // create a new chunk

        }

        // add data to chunk

        size_t c = std::min(chunk->left(), (n - i));

        chunk->addSamples(&samples[i], c);

        i += c;

    }

    _size += n;

}

void ChunkedBuffer::clear()

{

    // delete all chunks

    for (auto chunk : chunks)

    {

        delete chunk;

    }

    chunks.clear();

    numChunks = 0;

    _size = 0;

    // create first chunk

    addNewChunk();

}

DataChunk* ChunkedBuffer::addNewChunk()

{

    auto chunk = new DataChunk(_size, CHUNK_SIZE);

    chunks.append(chunk);

    return chunk;

}

unsigned ChunkedBuffer::size() const

{

    return _size;

}

Range ChunkedBuffer::limits() const

{

    // TODO: it should be possible to cache boundingRect and only

    // update on 'addSamples' and when dropping chunks

    // find ymin and ymax

    double ymin = chunks.first()->min();

    double ymax = chunks.first()->max();

    for (auto c : chunks)

    {

        ymin = std::min(ymin, c->min());

        ymax = std::max(ymax, c->max());

    }

    return {ymin, ymax};

}

double ChunkedBuffer::sample(unsigned i) const

{

    int chunk_index = i / CHUNK_SIZE;

    int chunk_offset = i % CHUNK_SIZE;

    return chunks[chunk_index]->sample(chunk_offset);

}

void ChunkedBuffer::resize(unsigned n)

{

    // TODO what to do for ChunkedBuffer::resize

}