/***************************************************************************
 *                                                                         *
 *   LinuxSampler - modular, streaming capable sampler                     *
 *                                                                         *
 *   Copyright (C) 2003, 2004 by Benno Senoner and Christian Schoenebeck   *
 *   Copyright (C) 2005 - 2025 Christian Schoenebeck                       *
 *                                                                         *
 *   This program 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 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 *   This program 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 this program; if not, write to the Free Software           *
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston,                 *
 *   MA  02111-1307  USA                                                   *
 ***************************************************************************/

#ifndef __LS_AUDIOCHANNEL_H__
#define __LS_AUDIOCHANNEL_H__

#include <map>
#include <vector>
#include <string.h>
#include "../../common/global.h"
#include "../../common/Exception.h"
#include "../DeviceParameter.h"

namespace LinuxSampler {

    /** Audio Channel (always mono)
     *
     * This class is used for routing audio signals between arbitrary sources
     * and destinations. You can either create a normal channel like:
     * @code
     *	AudioChannel c1(512); // create unnamed channel
     *	AudioChannel c2(512, "Effect send mono channel"); // create named channel
     * @endcode
     * Or you can create a mix channel, e.g. the following would create a
     * normal channel first, and the second channel is just a copy of the
     * first channel:
     * @code
     *	AudioChannel mono_chan(512, "Effect send channel"); // real channel
     *	AudioChannel mix_chan(&mono_chan, "Effect send mono channel"); // mix channel
     * @endcode
     * So in the last example, when writing to 'mix_chan' the signal will
     * actually be mixed to the 'mono_chan' channel, so this is an easy way
     * to downmix a signal source which has more audio channels than the
     * signal destination can offer.
     */
    class AudioChannel {
        public:
            class ParameterName : public DeviceRuntimeParameterString {
                public:
                    ParameterName(String s) : DeviceRuntimeParameterString(s) {}
                    virtual String              Description()  OVERRIDE          { return "Arbitrary name";      }
                    virtual bool                Fix() OVERRIDE                   { return false;                 }
                    virtual std::vector<String> PossibilitiesAsString() OVERRIDE { return std::vector<String>(); }
                    virtual void                OnSetValue(String s)  OVERRIDE   { /* nothing to do */           }
            };

            class ParameterIsMixChannel : public DeviceRuntimeParameterBool {
                public:
                    ParameterIsMixChannel(bool b) : DeviceRuntimeParameterBool(b) {}
                    virtual String Description() OVERRIDE                        { return "Whether real channel or mixed to another channel"; }
                    virtual bool   Fix() OVERRIDE                                { return true;                                               }
                    virtual void   OnSetValue(bool b) LS_THROWS(Exception) OVERRIDE { /* cannot happen, as parameter is fix */                }
            };

            class ParameterMixChannelDestination : public DeviceRuntimeParameterInt {
                public:
                    ParameterMixChannelDestination(int i) : DeviceRuntimeParameterInt(i) {}
                    virtual String           Description() OVERRIDE                       { return "Destination channel of this mix channel";                 }
                    virtual bool             Fix() OVERRIDE                               { return true;                                                      }
                    virtual optional<int>    RangeMinAsInt() OVERRIDE                     { return optional<int>::nothing; /*TODO: needs to be implemented */ }
                    virtual optional<int>    RangeMaxAsInt() OVERRIDE                     { return optional<int>::nothing; /*TODO: needs to be implemented */ }
                    virtual std::vector<int> PossibilitiesAsInt() OVERRIDE                { return std::vector<int>();     /*TODO: needs to be implemented */ }
                    virtual void             OnSetValue(int i) LS_THROWS(Exception) OVERRIDE { /*TODO: needs to be implemented */                             }
            };

            // attributes
            //String Name;  ///< Arbitrary name of this audio channel

            // methods
            inline float*        Buffer()     { return pBuffer;      } ///< Audio signal buffer
            void SetBuffer(float* pBuffer)    { this->pBuffer = pBuffer; }
            inline AudioChannel* MixChannel() { return pMixChannel;  } ///< In case this channel is a mix channel, then it will return a pointer to the real channel this channel refers to, NULL otherwise.
            inline void          Clear()      { memset(pBuffer, 0, uiBufferSize * sizeof(float)); } ///< Reset audio buffer with silence
            inline void          Clear(uint Samples) { memset(pBuffer, 0, Samples * sizeof(float)); } ///< Reset audio buffer with silence
            void CopyTo(AudioChannel* pDst, const uint Samples);
            void CopyTo(AudioChannel* pDst, const uint Samples, const float fLevel);
            void MixTo(AudioChannel* pDst, const uint Samples);
            void MixTo(AudioChannel* pDst, const uint Samples, const float fLevel);
            std::map<String,DeviceRuntimeParameter*> ChannelParameters();

            // constructors / destructor
            AudioChannel(uint ChannelNr, uint BufferSize);
            AudioChannel(uint ChannelNr, float* pBuffer, uint BufferSize);
            AudioChannel(uint ChannelNr, AudioChannel* pMixChannelDestination);
            virtual ~AudioChannel();
        protected:
            uint ChannelNr;
            std::map<String,DeviceRuntimeParameter*> Parameters;
        private:
            float*        pBuffer;
            uint          uiBufferSize;
            AudioChannel* pMixChannel;
            bool          UsesExternalBuffer;
    };
}

#endif // __LS_AUDIOCHANNEL_H__
