/**
 * Furnace Tracker - multi-system chiptune tracker
 * Copyright (C) 2021-2024 tildearrow and contributors
 *
 * 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.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "engine.h"
#include "../ta-log.h"

#define WRITE_TICK(x) \
  if (binary) { \
    if (!wroteTick[x]) { \
      wroteTick[x]=true; \
      if (tick-lastTick[x]>255) { \
        chanStream[x]->writeC(0xfc); \
        chanStream[x]->writeS(tick-lastTick[x]); \
      } else if (tick-lastTick[x]>1) { \
        delayPopularity[tick-lastTick[x]]++; \
        chanStream[x]->writeC(0xfd); \
        chanStream[x]->writeC(tick-lastTick[x]); \
      } else if (tick-lastTick[x]>0) { \
        chanStream[x]->writeC(0xfe); \
      } \
      lastTick[x]=tick; \
    } \
  } else { \
    if (!wroteTickGlobal) { \
      wroteTickGlobal=true; \
      w->writeText(fmt::sprintf(">> TICK %d\n",tick)); \
    } \
  }

void writePackedCommandValues(SafeWriter* w, const DivCommand& c) {
  switch (c.cmd) {
    case DIV_CMD_NOTE_ON:
      if (c.value==DIV_NOTE_NULL) {
        w->writeC(0xb4);
      } else {
        w->writeC(CLAMP(c.value+60,0,0xb3));
      }
      break;
    case DIV_CMD_NOTE_OFF:
    case DIV_CMD_NOTE_OFF_ENV:
    case DIV_CMD_ENV_RELEASE:
    case DIV_CMD_INSTRUMENT:
    case DIV_CMD_PANNING:
    case DIV_CMD_PRE_PORTA:
    case DIV_CMD_HINT_VIBRATO:
    case DIV_CMD_HINT_VIBRATO_RANGE:
    case DIV_CMD_HINT_VIBRATO_SHAPE:
    case DIV_CMD_HINT_PITCH:
    case DIV_CMD_HINT_ARPEGGIO:
    case DIV_CMD_HINT_VOLUME:
    case DIV_CMD_HINT_PORTA:
    case DIV_CMD_HINT_VOL_SLIDE:
    case DIV_CMD_HINT_LEGATO:
      w->writeC((unsigned char)c.cmd+0xb4);
      break;
    default:
      w->writeC(0xf0); // unoptimized extended command
      w->writeC(c.cmd);
      break;
  }
  switch (c.cmd) {
    case DIV_CMD_HINT_LEGATO:
      if (c.value==DIV_NOTE_NULL) {
        w->writeC(0xff);
      } else {
        w->writeC(c.value+60);
      }
      break;
    case DIV_CMD_NOTE_ON:
    case DIV_CMD_NOTE_OFF:
    case DIV_CMD_NOTE_OFF_ENV:
    case DIV_CMD_ENV_RELEASE:
      break;
    case DIV_CMD_INSTRUMENT:
    case DIV_CMD_HINT_VIBRATO_RANGE:
    case DIV_CMD_HINT_VIBRATO_SHAPE:
    case DIV_CMD_HINT_PITCH:
    case DIV_CMD_HINT_VOLUME:
      w->writeC(c.value);
      break;
    case DIV_CMD_PANNING:
    case DIV_CMD_HINT_VIBRATO:
    case DIV_CMD_HINT_ARPEGGIO:
    case DIV_CMD_HINT_PORTA:
      w->writeC(c.value);
      w->writeC(c.value2);
      break;
    case DIV_CMD_PRE_PORTA:
      w->writeC((c.value?0x80:0)|(c.value2?0x40:0));
      break;
    case DIV_CMD_HINT_VOL_SLIDE:
      w->writeS(c.value);
      break;
    case DIV_CMD_SAMPLE_MODE:
    case DIV_CMD_SAMPLE_FREQ:
    case DIV_CMD_SAMPLE_BANK:
    case DIV_CMD_SAMPLE_POS:
    case DIV_CMD_SAMPLE_DIR:
    case DIV_CMD_FM_HARD_RESET:
    case DIV_CMD_FM_LFO:
    case DIV_CMD_FM_LFO_WAVE:
    case DIV_CMD_FM_FB:
    case DIV_CMD_FM_EXTCH:
    case DIV_CMD_FM_AM_DEPTH:
    case DIV_CMD_FM_PM_DEPTH:
    case DIV_CMD_STD_NOISE_FREQ:
    case DIV_CMD_STD_NOISE_MODE:
    case DIV_CMD_WAVE:
    case DIV_CMD_GB_SWEEP_TIME:
    case DIV_CMD_GB_SWEEP_DIR:
    case DIV_CMD_PCE_LFO_MODE:
    case DIV_CMD_PCE_LFO_SPEED:
    case DIV_CMD_NES_DMC:
    case DIV_CMD_C64_CUTOFF:
    case DIV_CMD_C64_RESONANCE:
    case DIV_CMD_C64_FILTER_MODE:
    case DIV_CMD_C64_RESET_TIME:
    case DIV_CMD_C64_RESET_MASK:
    case DIV_CMD_C64_FILTER_RESET:
    case DIV_CMD_C64_DUTY_RESET:
    case DIV_CMD_C64_EXTENDED:
    case DIV_CMD_AY_ENVELOPE_SET:
    case DIV_CMD_AY_ENVELOPE_LOW:
    case DIV_CMD_AY_ENVELOPE_HIGH:
    case DIV_CMD_AY_ENVELOPE_SLIDE:
    case DIV_CMD_AY_NOISE_MASK_AND:
    case DIV_CMD_AY_NOISE_MASK_OR:
    case DIV_CMD_AY_AUTO_ENVELOPE:
    case DIV_CMD_FDS_MOD_DEPTH:
    case DIV_CMD_FDS_MOD_HIGH:
    case DIV_CMD_FDS_MOD_LOW:
    case DIV_CMD_FDS_MOD_POS:
    case DIV_CMD_FDS_MOD_WAVE:
    case DIV_CMD_SAA_ENVELOPE:
    case DIV_CMD_AMIGA_FILTER:
    case DIV_CMD_AMIGA_AM:
    case DIV_CMD_AMIGA_PM:
    case DIV_CMD_MACRO_OFF:
    case DIV_CMD_MACRO_ON:
    case DIV_CMD_HINT_ARP_TIME:
      w->writeC(1); // length
      w->writeC(c.value);
      break;
    case DIV_CMD_FM_TL:
    case DIV_CMD_FM_AM:
    case DIV_CMD_FM_AR:
    case DIV_CMD_FM_DR:
    case DIV_CMD_FM_SL:
    case DIV_CMD_FM_D2R:
    case DIV_CMD_FM_RR:
    case DIV_CMD_FM_DT:
    case DIV_CMD_FM_DT2:
    case DIV_CMD_FM_RS:
    case DIV_CMD_FM_KSR:
    case DIV_CMD_FM_VIB:
    case DIV_CMD_FM_SUS:
    case DIV_CMD_FM_WS:
    case DIV_CMD_FM_SSG:
    case DIV_CMD_FM_REV:
    case DIV_CMD_FM_EG_SHIFT:
    case DIV_CMD_FM_MULT:
    case DIV_CMD_FM_FINE:
    case DIV_CMD_AY_IO_WRITE:
    case DIV_CMD_AY_AUTO_PWM:
    case DIV_CMD_SURROUND_PANNING:
      w->writeC(2); // length
      w->writeC(c.value);
      w->writeC(c.value2);
      break;
    case DIV_CMD_C64_FINE_DUTY:
    case DIV_CMD_C64_FINE_CUTOFF:
    case DIV_CMD_LYNX_LFSR_LOAD:
      w->writeC(2); // length
      w->writeS(c.value);
      break;
    case DIV_CMD_FM_FIXFREQ:
      w->writeC(2); // length
      w->writeS((c.value<<12)|(c.value2&0x7ff));
      break;
    case DIV_CMD_NES_SWEEP:
      w->writeC(1); // length
      w->writeC((c.value?8:0)|(c.value2&0x77));
      break;
    default:
      logW("unimplemented command %s!",cmdName[c.cmd]);
      w->writeC(0); // length
      break;
  }
}

SafeWriter* DivEngine::saveCommand(bool binary) {
  stop();
  repeatPattern=false;
  shallStop=false;
  setOrder(0);
  BUSY_BEGIN_SOFT;
  // determine loop point
  int loopOrder=0;
  int loopRow=0;
  int loopEnd=0;
  walkSong(loopOrder,loopRow,loopEnd);
  logI("loop point: %d %d",loopOrder,loopRow);

  int cmdPopularity[256];
  int delayPopularity[256];

  int sortedCmdPopularity[16];
  int sortedDelayPopularity[16];
  unsigned char sortedCmd[16];
  unsigned char sortedDelay[16];
  
  SafeWriter* chanStream[DIV_MAX_CHANS];
  unsigned int chanStreamOff[DIV_MAX_CHANS];
  bool wroteTick[DIV_MAX_CHANS];

  memset(cmdPopularity,0,256*sizeof(int));
  memset(delayPopularity,0,256*sizeof(int));
  memset(chanStream,0,DIV_MAX_CHANS*sizeof(void*));
  memset(chanStreamOff,0,DIV_MAX_CHANS*sizeof(unsigned int));
  memset(sortedCmdPopularity,0,16*sizeof(int));
  memset(sortedDelayPopularity,0,16*sizeof(int));
  memset(sortedCmd,0,16);
  memset(sortedDelay,0,16);

  SafeWriter* w=new SafeWriter;
  w->init();

  // write header
  if (binary) {
    w->write("FCS",4);
    w->writeI(chans);
    // offsets
    for (int i=0; i<chans; i++) {
      chanStream[i]=new SafeWriter;
      chanStream[i]->init();
      w->writeI(0);
    }
    // preset delays and speed dial
    for (int i=0; i<32; i++) {
      w->writeC(0);
    }
  } else {
    w->writeText("# Furnace Command Stream\n\n");

    w->writeText("[Information]\n");
    w->writeText(fmt::sprintf("name: %s\n",song.name));
    w->writeText(fmt::sprintf("author: %s\n",song.author));
    w->writeText(fmt::sprintf("category: %s\n",song.category));
    w->writeText(fmt::sprintf("system: %s\n",song.systemName));

    w->writeText("\n");

    w->writeText("[SubSongInformation]\n");
    w->writeText(fmt::sprintf("name: %s\n",curSubSong->name));
    w->writeText(fmt::sprintf("tickRate: %f\n",curSubSong->hz));

    w->writeText("\n");

    w->writeText("[SysDefinition]\n");
    // TODO

    w->writeText("\n");
  }

  // play the song ourselves
  bool done=false;
  playSub(false);
  
  if (!binary) {
    w->writeText("[Stream]\n");
  }
  int tick=0;
  bool oldCmdStreamEnabled=cmdStreamEnabled;
  cmdStreamEnabled=true;
  double curDivider=divider;
  int lastTick[DIV_MAX_CHANS];

  memset(lastTick,0,DIV_MAX_CHANS*sizeof(int));
  while (!done) {
    if (nextTick(false,true) || !playing) {
      done=true;
    }
    // get command stream
    bool wroteTickGlobal=false;
    memset(wroteTick,0,DIV_MAX_CHANS*sizeof(bool));
    if (curDivider!=divider) {
      curDivider=divider;
      WRITE_TICK(0);
      if (binary) {
        chanStream[0]->writeC(0xfb);
        chanStream[0]->writeI((int)(curDivider*65536));
      } else {
        w->writeText(fmt::sprintf(">> SET_RATE %f\n",curDivider));
      }
    }
    for (DivCommand& i: cmdStream) {
      switch (i.cmd) {
        // strip away hinted/useless commands
        case DIV_ALWAYS_SET_VOLUME:
          break;
        case DIV_CMD_GET_VOLUME:
          break;
        case DIV_CMD_VOLUME:
          break;
        case DIV_CMD_NOTE_PORTA:
          break;
        case DIV_CMD_LEGATO:
          break;
        case DIV_CMD_PITCH:
          break;
        case DIV_CMD_PRE_NOTE:
          break;
        default:
          WRITE_TICK(i.chan);
          if (binary) {
            cmdPopularity[i.cmd]++;
            writePackedCommandValues(chanStream[i.chan],i);
          } else {
            w->writeText(fmt::sprintf("  %d: %s %d %d\n",i.chan,cmdName[i.cmd],i.value,i.value2));
          }
          break;
      }
    }
    cmdStream.clear();
    tick++;
  }
  cmdStreamEnabled=oldCmdStreamEnabled;

  if (binary) {
    int sortCand=-1;
    int sortPos=0;
    while (sortPos<16) {
      sortCand=-1;
      for (int i=DIV_CMD_SAMPLE_MODE; i<256; i++) {
        if (cmdPopularity[i]) {
          if (sortCand==-1) {
            sortCand=i;
          } else if (cmdPopularity[sortCand]<cmdPopularity[i]) {
            sortCand=i;
          }
        }
      }
      if (sortCand==-1) break;

      sortedCmdPopularity[sortPos]=cmdPopularity[sortCand];
      sortedCmd[sortPos]=sortCand;
      cmdPopularity[sortCand]=0;
      sortPos++;
    }

    sortCand=-1;
    sortPos=0;
    while (sortPos<16) {
      sortCand=-1;
      for (int i=0; i<256; i++) {
        if (delayPopularity[i]) {
          if (sortCand==-1) {
            sortCand=i;
          } else if (delayPopularity[sortCand]<delayPopularity[i]) {
            sortCand=i;
          }
        }
      }
      if (sortCand==-1) break;

      sortedDelayPopularity[sortPos]=delayPopularity[sortCand];
      sortedDelay[sortPos]=sortCand;
      delayPopularity[sortCand]=0;
      sortPos++;
    }

    for (int i=0; i<chans; i++) {
      chanStream[i]->writeC(0xff);
      // optimize stream
      SafeWriter* oldStream=chanStream[i];
      SafeReader* reader=oldStream->toReader();
      chanStream[i]=new SafeWriter;
      chanStream[i]->init();

      while (1) {
        try {
          unsigned char next=reader->readC();
          switch (next) {
            case 0xb8: // instrument
            case 0xc0: // pre porta
            case 0xc3: // vibrato range
            case 0xc4: // vibrato shape
            case 0xc5: // pitch
            case 0xc7: // volume
            case 0xca: // legato
              chanStream[i]->writeC(next);
              next=reader->readC();
              chanStream[i]->writeC(next);
              break;
            case 0xbe: // panning
            case 0xc2: // vibrato
            case 0xc6: // arpeggio
            case 0xc8: // vol slide
            case 0xc9: // porta
              chanStream[i]->writeC(next);
              next=reader->readC();
              chanStream[i]->writeC(next);
              next=reader->readC();
              chanStream[i]->writeC(next);
              break;
            case 0xf0: { // full command (pre)
              unsigned char cmd=reader->readC();
              bool foundShort=false;
              for (int j=0; j<16; j++) {
                if (sortedCmd[j]==cmd) {
                  chanStream[i]->writeC(0xd0+j);
                  foundShort=true;
                  break;
                }
              }
              if (!foundShort) {
                chanStream[i]->writeC(0xf7); // full command
                chanStream[i]->writeC(cmd);
              }

              unsigned char cmdLen=reader->readC();
              logD("cmdLen: %d",cmdLen);
              for (unsigned char j=0; j<cmdLen; j++) {
                next=reader->readC();
                chanStream[i]->writeC(next);
              }
              break;
            }
            case 0xfb: // tick rate
              chanStream[i]->writeC(next);
              next=reader->readC();
              chanStream[i]->writeC(next);
              next=reader->readC();
              chanStream[i]->writeC(next);
              next=reader->readC();
              chanStream[i]->writeC(next);
              next=reader->readC();
              chanStream[i]->writeC(next);
              break;
            case 0xfc: { // 16-bit wait
              unsigned short delay=reader->readS();
              bool foundShort=false;
              for (int j=0; j<16; j++) {
                if (sortedDelay[j]==delay) {
                  chanStream[i]->writeC(0xe0+j);
                  foundShort=true;
                  break;
                }
              }
              if (!foundShort) {
                chanStream[i]->writeC(next);
                chanStream[i]->writeS(delay);
              }
              break;
            }
            case 0xfd: { // 8-bit wait
              unsigned char delay=reader->readC();
              bool foundShort=false;
              for (int j=0; j<16; j++) {
                if (sortedDelay[j]==delay) {
                  chanStream[i]->writeC(0xe0+j);
                  foundShort=true;
                  break;
                }
              }
              if (!foundShort) {
                chanStream[i]->writeC(next);
                chanStream[i]->writeC(delay);
              }
              break;
            }
            default:
              chanStream[i]->writeC(next);
              break;
          }
        } catch (EndOfFileException& e) {
          break;
        }
      }

      oldStream->finish();
      delete oldStream;
    }

    for (int i=0; i<chans; i++) {
      chanStreamOff[i]=w->tell();
      logI("- %d: off %x size %ld",i,chanStreamOff[i],chanStream[i]->size());
      w->write(chanStream[i]->getFinalBuf(),chanStream[i]->size());
      chanStream[i]->finish();
      delete chanStream[i];
    }

    w->seek(8,SEEK_SET);
    for (int i=0; i<chans; i++) {
      w->writeI(chanStreamOff[i]);
    }

    logD("delay popularity:");
    for (int i=0; i<16; i++) {
      w->writeC(sortedDelay[i]);
      if (sortedDelayPopularity[i]) logD("- %d: %d",sortedDelay[i],sortedDelayPopularity[i]);
    }

    logD("command popularity:");
    for (int i=0; i<16; i++) {
      w->writeC(sortedCmd[i]);
      if (sortedCmdPopularity[i]) logD("- %s: %d",cmdName[sortedCmd[i]],sortedCmdPopularity[i]);
    }
  } else {
    if (!playing) {
      w->writeText(">> END\n");
    } else {
      w->writeText(">> LOOP 0\n");
    }
  }

  remainingLoops=-1;
  playing=false;
  freelance=false;
  extValuePresent=false;
  BUSY_END;

  return w;
}