/*
  AudioGeneratorMOD
  Audio output generator that plays Amiga MOD tracker files
    
  Copyright (C) 2017  Earle F. Philhower, III

  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 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/>.
*/

#ifndef _AUDIOGENERATORMOD_H
#define _AUDIOGENERATORMOD_H

#include "AudioGenerator.h"

class AudioGeneratorMOD : public AudioGenerator
{
  public:
    AudioGeneratorMOD();
    virtual ~AudioGeneratorMOD() override;
    virtual bool begin(AudioFileSource *source, AudioOutput *output) override;
    virtual bool loop() override;
    virtual bool stop() override;
    virtual bool isRunning() override { return running; }
    bool SetSampleRate(int hz) { if (running || (hz < 1) || (hz > 96000) ) return false; sampleRate = hz; return true; }
    bool SetBufferSize(int sz) { if (running || (sz < 1) ) return false; fatBufferSize = sz; return true; }
    bool SetStereoSeparation(int sep) { if (running || (sep<0) || (sep>64)) return false; stereoSeparation = sep; return true; }
    bool SetPAL(bool use) { if (running) return false; usePAL = use; return true; }

  protected:
    bool LoadMOD();
    bool LoadHeader();
    void GetSample(int16_t sample[2]);
    bool RunPlayer();
    void LoadSamples();
    bool LoadPattern(uint8_t pattern);
    bool ProcessTick();
    bool ProcessRow();
    void Tremolo(uint8_t channel);
    void Portamento(uint8_t channel);
    void Vibrato(uint8_t channel);


  protected:
    int mixerTick;
    enum {BITDEPTH = 15};
    int sampleRate; 
    int fatBufferSize; //(6*1024) // File system buffers per-CHANNEL (i.e. total mem required is 4 * FATBUFFERSIZE)
    enum {DIVIDER = 10};             // Fixed-point mantissa used for integer arithmetic
    int stereoSeparation; //STEREOSEPARATION = 32;    // 0 (max) to 64 (mono)
    bool usePAL;
    
    // Hz = 7093789 / (amigaPeriod * 2) for PAL
    // Hz = 7159091 / (amigaPeriod * 2) for NTSC
    int AMIGA;
    void UpdateAmiga() { AMIGA = ((usePAL?7159091:7093789) / 2 / sampleRate << DIVIDER); }
    
    enum {ROWS = 64, SAMPLES = 31, CHANNELS = 4, NONOTE = 0xFFFF, NONOTE8 = 0xff };

    typedef struct Sample {
      uint16_t length;
      int8_t fineTune;
      uint8_t volume;
      uint16_t loopBegin;
      uint16_t loopLength;
    } Sample;
    
    typedef struct mod {
      Sample samples[SAMPLES];
      uint8_t songLength;
      uint8_t numberOfPatterns;
      uint8_t order[128];
      uint8_t numberOfChannels;
    } mod;
    
    // Save 256 bytes by storing raw note values, unpack with macro NOTE
    typedef struct Pattern {
      uint8_t sampleNumber[ROWS][CHANNELS];
      uint8_t note8[ROWS][CHANNELS];
      uint8_t effectNumber[ROWS][CHANNELS];
      uint8_t effectParameter[ROWS][CHANNELS];
    } Pattern;
    
    typedef struct player {
      Pattern currentPattern;
    
      uint32_t amiga;
      uint16_t samplesPerTick;
      uint8_t speed;
      uint8_t tick;
      uint8_t row;
      uint8_t lastRow;
    
      uint8_t orderIndex;
      uint8_t oldOrderIndex;
      uint8_t patternDelay;
      uint8_t patternLoopCount[CHANNELS];
      uint8_t patternLoopRow[CHANNELS];
    
      uint8_t lastSampleNumber[CHANNELS];
      int8_t volume[CHANNELS];
      uint16_t lastNote[CHANNELS];
      uint16_t amigaPeriod[CHANNELS];
      int16_t lastAmigaPeriod[CHANNELS];
    
      uint16_t portamentoNote[CHANNELS];
      uint8_t portamentoSpeed[CHANNELS];
    
      uint8_t waveControl[CHANNELS];
    
      uint8_t vibratoSpeed[CHANNELS];
      uint8_t vibratoDepth[CHANNELS];
      int8_t vibratoPos[CHANNELS];
    
      uint8_t tremoloSpeed[CHANNELS];
      uint8_t tremoloDepth[CHANNELS];
      int8_t tremoloPos[CHANNELS];
    } player;
    
    typedef struct mixer {
      uint32_t sampleBegin[SAMPLES];
      uint32_t sampleEnd[SAMPLES];
      uint32_t sampleloopBegin[SAMPLES];
      uint16_t sampleLoopLength[SAMPLES];
      uint32_t sampleLoopEnd[SAMPLES];
    
      uint8_t channelSampleNumber[CHANNELS];
      uint32_t channelSampleOffset[CHANNELS];
      uint16_t channelFrequency[CHANNELS];
      uint8_t channelVolume[CHANNELS];
      uint8_t channelPanning[CHANNELS];
    } mixer;
    
    typedef struct fatBuffer {
      uint8_t *channels[CHANNELS]; // Make dynamically allocated [FATBUFFERSIZE];
      uint32_t samplePointer[CHANNELS];
      uint8_t channelSampleNumber[CHANNELS];
    } fatBuffer;

    // Effects
    typedef enum { ARPEGGIO = 0, PORTAMENTOUP, PORTAMENTODOWN, TONEPORTAMENTO, VIBRATO, PORTAMENTOVOLUMESLIDE,
                   VIBRATOVOLUMESLIDE, TREMOLO, SETCHANNELPANNING, SETSAMPLEOFFSET, VOLUMESLIDE, JUMPTOORDER,
                   SETVOLUME, BREAKPATTERNTOROW, ESUBSET, SETSPEED } EffectsValues;
    
    // 0xE subset
    typedef enum { SETFILTER = 0, FINEPORTAMENTOUP, FINEPORTAMENTODOWN, GLISSANDOCONTROL, SETVIBRATOWAVEFORM,
                   SETFINETUNE, PATTERNLOOP, SETTREMOLOWAVEFORM, SUBEFFECT8, RETRIGGERNOTE, FINEVOLUMESLIDEUP,
                   FINEVOLUMESLIDEDOWN, NOTECUT, NOTEDELAY, PATTERNDELAY, INVERTLOOP } Effect08Subvalues;
    
    // Our state lives here...
    player Player;
    mod Mod;
    mixer Mixer;
    fatBuffer FatBuffer;
};

#endif