/*
  Copyright © 2018 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 <limits>
#include "streamchannel.h"

StreamChannel::StreamChannel(unsigned i, const FrameBuffer* x,
              FrameBuffer* y, ChannelInfoModel* info)
{
    _index = i;
    _x = x;
    _y = y;
    _info = info;
}

StreamChannel::~StreamChannel()
{
    delete _y;
}

unsigned StreamChannel::index() const {return _index;}
QString StreamChannel::name() const {return _info->name(_index);};
QColor StreamChannel::color() const {return _info->color(_index);};
bool StreamChannel::visible() const {return _info->isVisible(_index);};
const FrameBuffer* StreamChannel::xData() const {return _x;}
const FrameBuffer* StreamChannel::yData() const {return _y;}
FrameBuffer* StreamChannel::yData() {return _y;}
const ChannelInfoModel* StreamChannel::info() const {return _info;}
void StreamChannel::setX(const FrameBuffer* x) {_x = x;};

double StreamChannel::findValue(double x) const
{
    int index = findIndex(x);
    if (index >= 0)
        return _y->sample(index);
    else
        return std::numeric_limits<double>::quiet_NaN();
}

int StreamChannel::findIndex(double x) const
{
    // TODO: optimize, implement in `framebuffer`
    bool first = true;
    for (int i = _x->size()-1; i > 0; i--)
    {
        double val = _x->sample(i);
        if (x >= val)
        {
            // TODO: optional linear approx. method
            // check if previous sample (bigger one) is actually closer
            if (!first && (x - val) > (_x->sample(i + 1) - x))
            {
                ++i;
            }

            return i;
        }
        first = false;
    }
    return -1;
}