/*
 *  This file is part of RawTherapee.
 *
 *  Copyright (c) 2004-2010 Gabor Horvath <hgabor@rawtherapee.com>
 *
 *  RawTherapee 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.
 *
 *  RawTherapee 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 RawTherapee.  If not, see <https://www.gnu.org/licenses/>.
 */
#pragma once

#include <vector>

class CurveEditor;

class CurveListener
{

private:
    bool multi;
public:
    CurveListener() : multi(false) {}
    virtual ~CurveListener() {}
    virtual void curveChanged () {}
    virtual void curveChanged (CurveEditor* ce) {}
    void setMulti(bool value)
    {
        multi = value;
    }
    bool isMulti()
    {
        return multi;
    }

    /** @brief Ask the reset curve for a given curve type
     * @param ce CurveEditor that we want to reset
     * @param curve Actual curve for the return value. The actual curve type (given by the first value of the vector)
     *              should be kept the same. Change the curve type if REALLY necessary! */
    virtual bool getResetCurve(CurveEditor *ce, std::vector<double> &curve)
    {
        return false;
    }

    /** @brief Blend pipette values from its different channels into a single value
    If the buffer has more than one channel and one channel, this method will blend them together.
    @param chan1 first channel's value
    @param chan2 second channel's value
    @param chan3 third channel's value
    @return the blended value */
    virtual float blendPipetteValues(CurveEditor *ce, float chan1, float chan2, float chan3)
    {
        float retVal = 0.f;
        int n = 0;

        if (chan1 != -1.f) {
            retVal += chan1;
            ++n;
        }

        if (chan2 != -1.f) {
            retVal += chan2;
            ++n;
        }

        if (chan3 != -1.f) {
            retVal += chan3;
            ++n;
        }

        if (n > 1) {
            retVal /= n;
        } else if (!n) {
            retVal = -1.f;
        }

        return retVal;
    }
};