/************************** BEGIN midi.h **************************/
/************************************************************************
 FAUST Architecture File
 Copyright (C) 2003-2017 GRAME, Centre National de Creation Musicale
 ---------------------------------------------------------------------
 This Architecture section 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.
 
 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, see <http://www.gnu.org/licenses/>.
 
 EXCEPTION : As a special exception, you may create a larger work
 that contains this FAUST architecture section and distribute
 that work under terms of your choice, so long as this FAUST
 architecture section is not modified.
 ************************************************************************/

#ifndef __midi__
#define __midi__

#include <vector>
#include <string>
#include <algorithm>
#include <assert.h>

class MapUI;

/**
 * A timestamped short MIDI message used with SOUL.
 */

// Force contiguous memory layout
#pragma pack (push, 1)
struct MIDIMessage
{
    uint32_t frameIndex;
    uint8_t byte0, byte1, byte2;
};
#pragma pack (pop)

/**
 * For timestamped MIDI messages.
 */
struct DatedMessage {
    
    double fDate;
    unsigned char fBuffer[3];
    size_t fSize;
    
    DatedMessage(double date, unsigned char* buffer, size_t size)
    :fDate(date), fSize(size)
    {
        assert(size <= 3);
        memcpy(fBuffer, buffer, size);
    }
    
    DatedMessage():fDate(0.0), fSize(0)
    {}
    
};

/**
 * MIDI processor definition.
 *
 * MIDI input or output handling classes will implement this interface,
 * so the same method names (keyOn, keyOff, ctrlChange...) will be used either
 * when decoding MIDI input or encoding MIDI output events.
 * MIDI channel is numbered in [0..15] in this layer.
 */
class midi {

    public:

        midi() {}
        virtual ~midi() {}

        // Additional time-stamped API for MIDI input
        virtual MapUI* keyOn(double, int channel, int pitch, int velocity)
        {
            return keyOn(channel, pitch, velocity);
        }
        
        virtual void keyOff(double, int channel, int pitch, int velocity = 0)
        {
            keyOff(channel, pitch, velocity);
        }
    
        virtual void keyPress(double, int channel, int pitch, int press)
        {
            keyPress(channel, pitch, press);
        }
        
        virtual void chanPress(double date, int channel, int press)
        {
            chanPress(channel, press);
        }
    
        virtual void pitchWheel(double, int channel, int wheel)
        {
            pitchWheel(channel, wheel);
        }
           
        virtual void ctrlChange(double, int channel, int ctrl, int value)
        {
            ctrlChange(channel, ctrl, value);
        }
    
        virtual void ctrlChange14bits(double, int channel, int ctrl, int value)
        {
            ctrlChange14bits(channel, ctrl, value);
        }
    
        virtual void rpn(double, int channel, int ctrl, int value)
        {
            rpn(channel, ctrl, value);
        }

        virtual void progChange(double, int channel, int pgm)
        {
            progChange(channel, pgm);
        }
    
        virtual void sysEx(double, std::vector<unsigned char>& message)
        {
            sysEx(message);
        }

        // MIDI sync
        virtual void startSync(double date)  {}
        virtual void stopSync(double date)   {}
        virtual void clock(double date)  {}

        // Standard MIDI API
        virtual MapUI* keyOn(int channel, int pitch, int velocity)      { return nullptr; }
        virtual void keyOff(int channel, int pitch, int velocity)       {}
        virtual void keyPress(int channel, int pitch, int press)        {}
        virtual void chanPress(int channel, int press)                  {}
        virtual void ctrlChange(int channel, int ctrl, int value)       {}
        virtual void ctrlChange14bits(int channel, int ctrl, int value) {}
        virtual void rpn(int channel, int ctrl, int value)              {}
        virtual void pitchWheel(int channel, int wheel)                 {}
        virtual void progChange(int channel, int pgm)                   {}
        virtual void sysEx(std::vector<unsigned char>& message)         {}

        enum MidiStatus {
            // channel voice messages
            MIDI_NOTE_OFF = 0x80,
            MIDI_NOTE_ON = 0x90,
            MIDI_CONTROL_CHANGE = 0xB0,
            MIDI_PROGRAM_CHANGE = 0xC0,
            MIDI_PITCH_BEND = 0xE0,
            MIDI_AFTERTOUCH = 0xD0,         // aka channel pressure
            MIDI_POLY_AFTERTOUCH = 0xA0,    // aka key pressure
            MIDI_CLOCK = 0xF8,
            MIDI_START = 0xFA,
            MIDI_CONT = 0xFB,
            MIDI_STOP = 0xFC,
            MIDI_SYSEX_START = 0xF0,
            MIDI_SYSEX_STOP = 0xF7
        };

        enum MidiCtrl {
            ALL_NOTES_OFF = 123,
            ALL_SOUND_OFF = 120
        };
    
        enum MidiNPN {
            PITCH_BEND_RANGE = 0
        };

};

/**
 * A class to decode NRPN and RPN messages, adapted from JUCE forum message:
 * https://forum.juce.com/t/14bit-midi-controller-support/11517
 */
class MidiNRPN {
    
    private:
    
        bool ctrlnew;
        int ctrlnum;
        int ctrlval;
        
        int nrpn_lsb, nrpn_msb;
        int data_lsb, data_msb;
        
        enum
        {
            midi_nrpn_lsb = 98,
            midi_nrpn_msb = 99,
            midi_rpn_lsb  = 100,
            midi_rpn_msb  = 101,
            midi_data_lsb = 38,
            midi_data_msb = 6
        };
    
    public:
        
        MidiNRPN(): ctrlnew(false), nrpn_lsb(-1), nrpn_msb(-1), data_lsb(-1), data_msb(-1)
        {}
        
        // return true if the message has been filtered
        bool process(int data1, int data2)
        {
            switch (data1)
            {
                case midi_nrpn_lsb: nrpn_lsb = data2; return true;
                case midi_nrpn_msb: nrpn_msb = data2; return true;
                case midi_rpn_lsb: {
                    if (data2 == 127) {
                        nrpn_lsb = data_lsb = -1;
                    } else {
                        nrpn_lsb = 0;
                        data_lsb = -1;
                    }
                    return true;
                }
                case midi_rpn_msb: {
                    if (data2 == 127) {
                        nrpn_msb = data_msb = -1;
                    } else {
                        nrpn_msb = 0;
                        data_msb = -1;
                    }
                    return true;
                }
                case midi_data_lsb:
                case midi_data_msb:
                {
                    if (data1 == midi_data_msb) {
                        if (nrpn_msb < 0) {
                            return false;
                        }
                        data_msb = data2;
                    } else { // midi_data_lsb
                        if (nrpn_lsb < 0) {
                            return false;
                        }
                        data_lsb = data2;
                    }
                    if (data_lsb >= 0 && data_msb >= 0) {
                        ctrlnum = (nrpn_msb << 7) | nrpn_lsb;
                        ctrlval = (data_msb << 7) | data_lsb;
                        data_lsb = data_msb = -1;
                        nrpn_msb = nrpn_lsb = -1;
                        ctrlnew = true;
                    }
                    return true;
                }
                default: return false;
            };
        }
        
        bool hasNewNRPN() { bool res = ctrlnew; ctrlnew = false; return res; }
        
        // results in [0, 16383]
        int getCtrl() const { return ctrlnum; }
        int getVal() const { return ctrlval; }
    
};

/**
 * A pure interface for MIDI handlers that can send/receive MIDI messages to/from 'midi' objects.
 */
struct midi_interface {
    virtual void addMidiIn(midi* midi_dsp)      = 0;
    virtual void removeMidiIn(midi* midi_dsp)   = 0;
    virtual ~midi_interface() {}
};

/****************************************************
 * Base class for MIDI input handling.
 *
 * Shared common code used for input handling:
 * - decoding Real-Time messages: handleSync
 * - decoding one data byte messages: handleData1
 * - decoding two data byte messages: handleData2
 * - getting ready messages in polling mode
 ****************************************************/
class midi_handler : public midi, public midi_interface {

    protected:

        std::vector<midi*> fMidiInputs;
        std::string fName;
        MidiNRPN fNRPN;
    
        int range(int min, int max, int val) { return (val < min) ? min : ((val >= max) ? max : val); }
  
    public:

        midi_handler(const std::string& name = "MIDIHandler"):midi_interface(), fName(name) {}
        virtual ~midi_handler() {}

        void addMidiIn(midi* midi_dsp) { if (midi_dsp) fMidiInputs.push_back(midi_dsp); }
        void removeMidiIn(midi* midi_dsp)
        {
            std::vector<midi*>::iterator it = std::find(fMidiInputs.begin(), fMidiInputs.end(), midi_dsp);
            if (it != fMidiInputs.end()) {
                fMidiInputs.erase(it);
            }
        }

        // Those 2 methods have to be implemented by subclasses
        virtual bool startMidi() { return true; }
        virtual void stopMidi() {}
    
        void setName(const std::string& name) { fName = name; }
        std::string getName() { return fName; }
    
        // To be used in polling mode
        virtual int recvMessages(std::vector<MIDIMessage>* message) { return 0; }
        virtual void sendMessages(std::vector<MIDIMessage>* message, int count) {}
    
        // MIDI Real-Time
        void handleClock(double time)
        {
            for (unsigned int i = 0; i < fMidiInputs.size(); i++) {
                fMidiInputs[i]->clock(time);
            }
        }
        
        void handleStart(double time)
        {
            for (unsigned int i = 0; i < fMidiInputs.size(); i++) {
                fMidiInputs[i]->startSync(time);
            }
        }
        
        void handleStop(double time)
        {
            for (unsigned int i = 0; i < fMidiInputs.size(); i++) {
                fMidiInputs[i]->stopSync(time);
            }
        }
    
        void handleSync(double time, int type)
        {
            if (type == MIDI_CLOCK) {
                handleClock(time);
            // We can consider start and continue as identical messages
            } else if ((type == MIDI_START) || (type == MIDI_CONT)) {
                handleStart(time);
            } else if (type == MIDI_STOP) {
                handleStop(time);
            }
        }
    
        // MIDI 1 data
        void handleProgChange(double time, int channel, int data1)
        {
            for (unsigned int i = 0; i < fMidiInputs.size(); i++) {
                fMidiInputs[i]->progChange(time, channel, data1);
            }
        }
    
        void handleAfterTouch(double time, int channel, int data1)
        {
            for (unsigned int i = 0; i < fMidiInputs.size(); i++) {
                fMidiInputs[i]->chanPress(time, channel, data1);
            }
        }

        void handleData1(double time, int type, int channel, int data1)
        {
            if (type == MIDI_PROGRAM_CHANGE) {
                handleProgChange(time, channel, data1);
            } else if (type == MIDI_AFTERTOUCH) {
                handleAfterTouch(time, channel, data1);
            }
        }
    
        // MIDI 2 datas
        void handleKeyOff(double time, int channel, int data1, int data2)
        {
            for (unsigned int i = 0; i < fMidiInputs.size(); i++) {
                fMidiInputs[i]->keyOff(time, channel, data1, data2);
            }
        }
        
        void handleKeyOn(double time, int channel, int data1, int data2)
        {
            if (data2 == 0) {
                handleKeyOff(time, channel, data1, data2);
            } else {
                for (unsigned int i = 0; i < fMidiInputs.size(); i++) {
                    fMidiInputs[i]->keyOn(time, channel, data1, data2);
                }
            }
        }
    
        void handleCtrlChange(double time, int channel, int data1, int data2)
        {
            // Special processing for NRPN and RPN
            if (fNRPN.process(data1, data2)) {
                if (fNRPN.hasNewNRPN()) {
                    for (unsigned int i = 0; i < fMidiInputs.size(); i++) {
                        fMidiInputs[i]->rpn(time, channel, fNRPN.getCtrl(), fNRPN.getVal());
                    }
                }
            } else {
                for (unsigned int i = 0; i < fMidiInputs.size(); i++) {
                    fMidiInputs[i]->ctrlChange(time, channel, data1, data2);
                }
            }
        }
        
        void handlePitchWheel(double time, int channel, int data1, int data2)
        {
            for (unsigned int i = 0; i < fMidiInputs.size(); i++) {
                fMidiInputs[i]->pitchWheel(time, channel, (data2 << 7) + data1);
            }
        }
    
        void handlePitchWheel(double time, int channel, int bend)
        {
            for (unsigned int i = 0; i < fMidiInputs.size(); i++) {
                fMidiInputs[i]->pitchWheel(time, channel, bend);
            }
        }
        
        void handlePolyAfterTouch(double time, int channel, int data1, int data2)
        {
            for (unsigned int i = 0; i < fMidiInputs.size(); i++) {
                fMidiInputs[i]->keyPress(time, channel, data1, data2);
            }
        }
  
        void handleData2(double time, int type, int channel, int data1, int data2)
        {
            if (type == MIDI_NOTE_OFF) {
                handleKeyOff(time, channel,  data1, data2);
            } else if (type == MIDI_NOTE_ON) {
                handleKeyOn(time, channel, data1, data2);
            } else if (type == MIDI_CONTROL_CHANGE) {
                handleCtrlChange(time, channel, data1, data2);
            } else if (type == MIDI_PITCH_BEND) {
                handlePitchWheel(time, channel, data1, data2);
            } else if (type == MIDI_POLY_AFTERTOUCH) {
                handlePolyAfterTouch(time, channel, data1, data2);
            }
        }
    
        // SysEx
        void handleSysex(double time, std::vector<unsigned char>& message)
        {
            for (unsigned int i = 0; i < fMidiInputs.size(); i++) {
                fMidiInputs[i]->sysEx(time, message);
            }
        }
    
        void handleMessage(double time, int type, std::vector<unsigned char>& message)
        {
            if (type == MIDI_SYSEX_START) {
                handleSysex(time, message);
            }
        }
  
};

#endif // __midi__
/**************************  END  midi.h **************************/