/*
   MicroDexed

   MicroDexed is a port of the Dexed sound engine
   (https://github.com/asb2m10/dexed) for the Teensy-3.5/3.6/4.x with audio shield.
   Dexed ist heavily based on https://github.com/google/music-synthesizer-for-android

   (c)2018-2023 H. Wirtz <wirtz@parasitstudio.de>
   (c)2021-2022 H. Wirtz <wirtz@parasitstudio.de>, M. Koslowski <positionhigh@gmx.de>

   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, write to the Free Software Foundation,
   Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA

*/

#include <Arduino.h>
#include "config.h"
#include <Wire.h>
#include <SD.h>
#include <ArduinoJson.h>
#include "dexed_sd.h"
#include "synth_dexed.h"
#if NUM_DRUMS > 0
#include "drumset.h"
extern void set_drums_volume(float vol);
//extern drum_config_t drum_config[];
#endif
#include <LiquidCrystal_I2C.h>
#include "disp_plus.h"

extern Disp_Plus<LiquidCrystal_I2C> display;

extern void init_MIDI_send_CC(void);
extern void check_configuration_dexed(uint8_t instance_id);
extern void check_configuration_performance(void);
extern void check_configuration_fx(void);
extern void check_configuration_epiano(void);
#if NUM_DRUMS > 0
extern void check_configuration_drums(void);
#endif
extern float midi_volume_transform(uint8_t midi_amp);
extern void handleStop(void);
extern void handleStart(void);
extern void dac_mute(void);
extern void dac_unmute(void);
extern void check_configuration_sys(void);
extern bool save_sys_flag;

/******************************************************************************
   SD BANK/VOICE LOADING
 ******************************************************************************/
bool load_sd_voice(uint8_t b, uint8_t v, uint8_t instance_id) {
  v = constrain(v, 0, MAX_VOICES - 1);
  b = constrain(b, 0, MAX_BANKS - 1);

  if (sd_card > 0) {
    File sysex;
    char filename[FILENAME_LEN];
    char bank_name[BANK_NAME_LEN];
    uint8_t data[128];

    get_bank_name(b, bank_name, sizeof(bank_name));
    snprintf_P(filename, sizeof(filename), PSTR("/%d/%s.syx"), b, bank_name);

    AudioNoInterrupts();
    sysex = SD.open(filename);
    AudioInterrupts();
    if (!sysex) {
#ifdef DEBUG
      Serial.print(F("E : Cannot open "));
      Serial.print(filename);
      Serial.println(F(" on SD."));
#endif
      return (false);
    }

    if (get_sd_voice(sysex, v, data)) {
#ifdef DEBUG
      char voice_name[VOICE_NAME_LEN];
      get_voice_name(b, v, voice_name, sizeof(voice_name));
      Serial.print(F("Loading voice from "));
      Serial.print(filename);
      Serial.print(F(" ["));
      Serial.print(voice_name);
      Serial.println(F("]"));
#endif
      uint8_t tmp_data[156];
      bool ret = MicroDexed[instance_id]->decodeVoice(tmp_data, data);
      MicroDexed[instance_id]->loadVoiceParameters(tmp_data);
#ifdef DEBUG
      show_patch(instance_id);
#endif

      AudioNoInterrupts();
      sysex.close();
      AudioInterrupts();
      configuration.dexed[instance_id].transpose = MicroDexed[instance_id]->getTranspose();
      configuration.dexed[instance_id].bank = b;
      configuration.dexed[instance_id].voice = v;

      uint8_t data_copy[156];
      MicroDexed[instance_id]->getVoiceData(data_copy);
      send_sysex_voice(configuration.dexed[instance_id].midi_channel, data_copy);
      init_MIDI_send_CC();
      return (ret);
    }
#ifdef DEBUG
    else
      Serial.println(F("E : Cannot load voice data"));
#endif
    AudioNoInterrupts();
    sysex.close();
    AudioInterrupts();
  }

  return (false);
}

bool save_sd_voice(uint8_t b, uint8_t v, uint8_t instance_id) {
  v = constrain(v, 0, MAX_VOICES - 1);
  b = constrain(b, 0, MAX_BANKS - 1);

  if (sd_card > 0) {
    File sysex;
    char filename[FILENAME_LEN];
    char bank_name[BANK_NAME_LEN];
    uint8_t data[128];

    get_bank_name(b, bank_name, sizeof(bank_name));
    snprintf_P(filename, sizeof(filename), PSTR("/%d/%s.syx"), b, bank_name);

    AudioNoInterrupts();
    sysex = SD.open(filename, FILE_WRITE);
    AudioInterrupts();
    if (!sysex) {
#ifdef DEBUG
      Serial.print(F("E : Cannot open "));
      Serial.print(filename);
      Serial.println(F(" on SD."));
#endif
      return (false);
    }

    MicroDexed[instance_id]->encodeVoice(data);

    if (put_sd_voice(sysex, v, data)) {
#ifdef DEBUG
      char voice_name[VOICE_NAME_LEN];

      MicroDexed[instance_id]->getName(voice_name);
      Serial.print(F("Saving voice to "));
      Serial.print(filename);
      Serial.print(F(" ["));
      Serial.print(voice_name);
      Serial.println(F("]"));
#endif
      AudioNoInterrupts();
      sysex.close();
      AudioInterrupts();

      return (true);
    }
#ifdef DEBUG
    else
      Serial.println(F("E : Cannot load voice data"));
#endif
    AudioNoInterrupts();
    sysex.close();
    AudioInterrupts();
  }

  return (false);
}

bool get_sd_voice(File sysex, uint8_t voice_number, uint8_t* data) {
  uint16_t n;
  int32_t bulk_checksum_calc = 0;
  int8_t bulk_checksum;

  AudioNoInterrupts();
  if (sysex.size() != 4104)  // check sysex size
  {
#ifdef DEBUG
    Serial.println(F("E : SysEx file size wrong."));
#endif
    return (false);
  }
  if (sysex.read() != 0xf0)  // check sysex start-byte
  {
#ifdef DEBUG
    Serial.println(F("E : SysEx start byte not found."));
#endif
    return (false);
  }
  if (sysex.read() != 0x43)  // check sysex vendor is Yamaha
  {
#ifdef DEBUG
    Serial.println(F("E : SysEx vendor not Yamaha."));
#endif
    return (false);
  }
  sysex.seek(4103);
  if (sysex.read() != 0xf7)  // check sysex end-byte
  {
#ifdef DEBUG
    Serial.println(F("E : SysEx end byte not found."));
#endif
    return (false);
  }
  sysex.seek(3);
  if (sysex.read() != 0x09)  // check for sysex type (0x09=32 voices)
  {
#ifdef DEBUG
    Serial.println(F("E : SysEx type not 32 voices."));
#endif
    return (false);
  }
  sysex.seek(4102);  // Bulk checksum
  bulk_checksum = sysex.read();

  sysex.seek(6);  // start of bulk data
  for (n = 0; n < 4096; n++) {
    uint8_t d = sysex.read();
    if (n >= voice_number * 128 && n < (voice_number + 1) * 128)
      data[n - (voice_number * 128)] = d;
    bulk_checksum_calc -= d;
  }
  bulk_checksum_calc &= 0x7f;
  AudioInterrupts();

#ifdef DEBUG
  Serial.print(F("Bulk checksum : 0x"));
  Serial.print(bulk_checksum_calc, HEX);
  Serial.print(F(" [0x"));
  Serial.print(bulk_checksum, HEX);
  Serial.println(F("]"));
#endif

  if (bulk_checksum_calc != bulk_checksum) {
#ifdef DEBUG
    Serial.print(F("E : Bulk checksum mismatch : 0x"));

    Serial.print(bulk_checksum_calc, HEX);
    Serial.print(F(" != 0x"));
    Serial.println(bulk_checksum, HEX);
#endif
    return (false);
  }

  // MicroDexed[0]->resetRenderTimeMax(); // necessary?

  return (true);
}

bool put_sd_voice(File sysex, uint8_t voice_number, uint8_t* data) {
  uint16_t n;
  int32_t bulk_checksum_calc = 0;

  AudioNoInterrupts();
  sysex.seek(0);

  if (sysex.size() != 4104)  // check sysex size
  {
#ifdef DEBUG
    Serial.println(F("E : SysEx file size wrong."));
#endif
    return (false);
  }
  if (sysex.read() != 0xf0)  // check sysex start-byte
  {
#ifdef DEBUG
    Serial.println(F("E : SysEx start byte not found."));
#endif
    return (false);
  }
  if (sysex.read() != 0x43)  // check sysex vendor is Yamaha
  {
#ifdef DEBUG
    Serial.println(F("E : SysEx vendor not Yamaha."));
#endif
    return (false);
  }
  sysex.seek(4103);
  if (sysex.read() != 0xf7)  // check sysex end-byte
  {
#ifdef DEBUG
    Serial.println(F("E : SysEx end byte not found."));
#endif
    return (false);
  }
  sysex.seek(3);
  if (sysex.read() != 0x09)  // check for sysex type (0x09=32 voices)
  {
#ifdef DEBUG
    Serial.println(F("E : SysEx type not 32 voices."));
#endif
    return (false);
  }

  sysex.seek(6 + (voice_number * 128));
  sysex.write(data, 128);

  // checksum calculation
  sysex.seek(6);  // start of bulk data
  for (n = 0; n < 4096; n++) {
    uint8_t d = sysex.read();
    bulk_checksum_calc -= d;
  }
  sysex.seek(4102);  // Bulk checksum
  sysex.write(bulk_checksum_calc & 0x7f);
  AudioInterrupts();

#ifdef DEBUG
  Serial.print(F("Bulk checksum : 0x"));
  Serial.println(bulk_checksum_calc & 0x7f, HEX);
#endif

  return (true);
}

bool save_sd_bank(const char* bank_filename, uint8_t* data) {
  char tmp[FILENAME_LEN];
  char tmp2[FILENAME_LEN];
  int bank_number;
  File root, entry;

  if (sd_card > 0) {
#ifdef DEBUG
    Serial.print(F("Trying so store "));
    Serial.print(bank_filename);
    Serial.println(F("."));
#endif

    // first remove old bank
    sscanf(bank_filename, "/%d/%s", &bank_number, tmp);
    snprintf_P(tmp, sizeof(tmp), PSTR("/%d"), bank_number);
    AudioNoInterrupts();
    root = SD.open(tmp);
    while (42 == 42) {
      entry = root.openNextFile();
      if (entry) {
        if (!entry.isDirectory()) {
#ifdef DEBUG
          Serial.print(F("Removing "));
          Serial.print(tmp);
          Serial.print(F("/"));
          Serial.println(entry.name());
#endif
          snprintf_P(tmp2, sizeof(tmp2), PSTR("%s/%s"), tmp, entry.name());
          entry.close();
#ifndef DEBUG
          SD.remove(tmp2);
#else
          bool r = SD.remove(tmp2);
          if (r == false) {
            Serial.print(F("E: cannot remove "));
            Serial.print(tmp2);
            Serial.println(F("."));
          }
#endif
          break;
        }
      } else {
        break;
      }
    }
    root.close();

    // store new bank at /<b>/<bank_name>.syx
#ifdef DEBUG
    Serial.print(F("Storing bank as "));
    Serial.print(bank_filename);
    Serial.print(F("..."));
#endif
    root = SD.open(bank_filename, FILE_WRITE);
    root.write(data, 4104);
    root.close();
    AudioInterrupts();
#ifdef DEBUG
    Serial.println(F(" done."));
#endif
  } else
    return (false);

  return (true);
}

/******************************************************************************
   SD DRUMSETTINGS
 ******************************************************************************/
#if NUM_DRUMS > 0
bool load_sd_drumsettings_json(uint8_t number) {
  if (number < 0)
    return (false);

  number = constrain(number, PERFORMANCE_NUM_MIN, PERFORMANCE_NUM_MAX);

  if (sd_card > 0) {
    File json;
    StaticJsonDocument<JSON_BUFFER_SIZE> data_json;
    char filename[CONFIG_FILENAME_LEN];

    snprintf_P(filename, sizeof(filename), PSTR("/%s/%d/%s.json"), PERFORMANCE_CONFIG_PATH, number, DRUMS_CONFIG_NAME);

    // first check if file exists...
    AudioNoInterrupts();
    if (SD.exists(filename)) {
      // ... and if: load
#ifdef DEBUG
      Serial.print(F("Found drums configuration ["));
      Serial.print(filename);
      Serial.println(F("]... loading"));
#endif
      json = SD.open(filename);
      if (json) {
        deserializeJson(data_json, json);
        json.close();
        AudioInterrupts();
#if defined(DEBUG) && defined(DEBUG_SHOW_JSON)
        Serial.println(F("Read JSON data:"));
        serializeJsonPretty(data_json, Serial);
        Serial.println();
#endif

        configuration.drums.main_vol = mapfloat(data_json["main_volume"], 0.0, 1.0, DRUMS_MAIN_VOL_MIN, DRUMS_MAIN_VOL_MAX);
        configuration.drums.midi_channel = data_json["midi_channel"];

        for (uint8_t i = 0; i < NUM_DRUMSET_CONFIG - 1; i++) {
          configuration.drums.midinote[i] = uint8_t(data_json["note"][i]);
          configuration.drums.pitch[i] = int8_t(data_json["pitch"][i]);
          configuration.drums.pan[i] = int8_t(data_json["pan"][i]);
          configuration.drums.vol_max[i] = uint8_t(data_json["vol_max"][i]);
          configuration.drums.vol_min[i] = uint8_t(data_json["vol_min"][i]);
          configuration.drums.reverb_send[i] = uint8_t(data_json["reverb_send"][i]);
        }
        check_configuration_drums();
        return (true);
      }
#ifdef DEBUG
      else {
        Serial.print(F("E : Cannot open "));
        Serial.print(filename);
        Serial.println(F(" on SD."));
      }
    } else {
      Serial.print(F("No "));
      Serial.print(filename);
      Serial.println(F(" available."));
#endif
    }
  }
  AudioInterrupts();
  return (false);
}

bool save_sd_drumsettings_json(uint8_t number) {
  char filename[CONFIG_FILENAME_LEN];
  number = constrain(number, PERFORMANCE_NUM_MIN, PERFORMANCE_NUM_MAX);

  if (sd_card > 0) {
    File json;
    StaticJsonDocument<JSON_BUFFER_SIZE> data_json;

    if (check_performance_directory(number)) {
      snprintf_P(filename, sizeof(filename), PSTR("/%s/%d/%s.json"), PERFORMANCE_CONFIG_PATH, number, DRUMS_CONFIG_NAME);

#ifdef DEBUG
      Serial.print(F("Saving drums config "));
      Serial.print(number);
      Serial.print(F(" to "));
      Serial.println(filename);
#endif
      AudioNoInterrupts();
      if (SD.exists(filename)) {
#ifdef DEBUG
        Serial.println(F("remove old drumsettings file"));
#endif
        SD.begin();
        SD.remove(filename);
      }
      json = SD.open(filename, FILE_WRITE);
      if (json) {
        data_json["main_volume"] = configuration.drums.main_vol;
        data_json["midi_channel"] = configuration.drums.midi_channel;

        for (uint8_t i = 0; i < NUM_DRUMSET_CONFIG - 1; i++) {
          data_json["note"][i] = configuration.drums.midinote[i];
          data_json["pitch"][i] = configuration.drums.pitch[i];
          data_json["pan"][i] = configuration.drums.pan[i];
          data_json["vol_max"][i] = configuration.drums.vol_max[i];
          data_json["vol_min"][i] = configuration.drums.vol_min[i];
          data_json["reverb_send"][i] = configuration.drums.reverb_send[i];
        }

#if defined(DEBUG) && defined(DEBUG_SHOW_JSON)
        Serial.println(F("Write JSON data:"));
        serializeJsonPretty(data_json, Serial);
        Serial.println();
#endif
        serializeJsonPretty(data_json, json);
        json.close();
        AudioInterrupts();
        return (true);
      } else {
#ifdef DEBUG
        Serial.print(F("E : Cannot open "));
        Serial.print(filename);
        Serial.println(F(" on SD."));
#endif
        AudioInterrupts();
        return (false);
      }
    } else {
      AudioInterrupts();
      return (false);
    }
  }
#ifdef DEBUG
  else {
    Serial.println(F("E: SD card not available"));
  }
#endif
  return (false);
}

/*
uint8_t find_drum_number_from_note(uint8_t note) {
  uint8_t number = 0;
  for (uint8_t d = 0; d < NUM_DRUMSET_CONFIG - 1; d++) {
    if (note == drum_config[d].midinote) {
      number = d;
      break;
    }
  }
  return number;
}
*/
#endif

/******************************************************************************
   SD VOICECONFIG
 ******************************************************************************/
bool load_sd_voiceconfig_json(uint8_t vc, uint8_t instance_id) {
  char filename[CONFIG_FILENAME_LEN];

  vc = constrain(vc, PERFORMANCE_NUM_MIN, PERFORMANCE_NUM_MAX);

  if (sd_card > 0) {
    File json;
    StaticJsonDocument<JSON_BUFFER_SIZE> data_json;

    snprintf_P(filename, sizeof(filename), PSTR("/%s/%d/%s%d.json"), PERFORMANCE_CONFIG_PATH, vc, VOICE_CONFIG_NAME, instance_id + 1);

    // first check if file exists...
    AudioNoInterrupts();
    if (SD.exists(filename)) {
      // ... and if: load
#ifdef DEBUG
      Serial.print(F("Found voice configuration ["));
      Serial.print(filename);
      Serial.println(F("]... loading..."));
#endif
      json = SD.open(filename);
      if (json) {
        deserializeJson(data_json, json);

        json.close();
        AudioInterrupts();

#if defined(DEBUG) && defined(DEBUG_SHOW_JSON)
        Serial.println(F("Read JSON data:"));
        serializeJsonPretty(data_json, Serial);
        Serial.println();
#endif
        configuration.dexed[instance_id].bank = data_json["bank"];
        configuration.dexed[instance_id].voice = data_json["voice"];
        configuration.dexed[instance_id].lowest_note = data_json["lowest_note"];
        configuration.dexed[instance_id].highest_note = data_json["highest_note"];
        configuration.dexed[instance_id].transpose = data_json["transpose"];
        configuration.dexed[instance_id].tune = data_json["tune"];
        configuration.dexed[instance_id].sound_intensity = data_json["sound_intensity"];
        configuration.dexed[instance_id].pan = data_json["pan"];
        configuration.dexed[instance_id].polyphony = data_json["polyphony"];
        configuration.dexed[instance_id].velocity_level = data_json["velocity_level"];
        configuration.dexed[instance_id].monopoly = data_json["monopoly"];
        configuration.dexed[instance_id].note_refresh = data_json["note_refresh"];
        configuration.dexed[instance_id].pb_range = data_json["pb_range"];
        configuration.dexed[instance_id].pb_step = data_json["pb_step"];
        configuration.dexed[instance_id].mw_range = data_json["mw_range"];
        configuration.dexed[instance_id].mw_assign = data_json["mw_assign"];
        configuration.dexed[instance_id].mw_mode = data_json["mw_mode"];
        configuration.dexed[instance_id].fc_range = data_json["fc_range"];
        configuration.dexed[instance_id].fc_assign = data_json["fc_assign"];
        configuration.dexed[instance_id].fc_mode = data_json["fc_mode"];
        configuration.dexed[instance_id].bc_range = data_json["bc_range"];
        configuration.dexed[instance_id].bc_assign = data_json["bc_assign"];
        configuration.dexed[instance_id].bc_mode = data_json["bc_mode"];
        configuration.dexed[instance_id].at_range = data_json["at_range"];
        configuration.dexed[instance_id].at_assign = data_json["at_assign"];
        configuration.dexed[instance_id].at_mode = data_json["at_mode"];
        configuration.dexed[instance_id].portamento_mode = data_json["portamento_mode"];
        configuration.dexed[instance_id].portamento_glissando = data_json["portamento_glissando"];
        configuration.dexed[instance_id].portamento_time = data_json["portamento_time"];
        configuration.dexed[instance_id].op_enabled = data_json["op_enabled"];
        configuration.dexed[instance_id].midi_channel = data_json["midi_channel"];
        configuration.dexed[instance_id].engine = data_json["engine"];

        check_configuration_dexed(instance_id);
        set_voiceconfig_params(instance_id);

        return (true);
      }
#ifdef DEBUG
      else {
        Serial.print(F("E : Cannot open "));
        Serial.print(filename);
        Serial.println(F(" on SD."));
      }
    } else {
      Serial.print(F("No "));
      Serial.print(filename);
      Serial.println(F(" available."));
#endif
    }
  }

  AudioInterrupts();
  return (false);
}

bool save_sd_voiceconfig_json(uint8_t vc, uint8_t instance_id) {
  char filename[CONFIG_FILENAME_LEN];

  vc = constrain(vc, PERFORMANCE_NUM_MIN, PERFORMANCE_NUM_MAX);

  if (sd_card > 0) {
    File json;
    StaticJsonDocument<JSON_BUFFER_SIZE> data_json;
    snprintf_P(filename, sizeof(filename), PSTR("/%s/%d/%s%d.json"), PERFORMANCE_CONFIG_PATH, vc, VOICE_CONFIG_NAME, instance_id + 1);

#ifdef DEBUG
    Serial.print(F("Saving voice config "));
    Serial.print(vc);
    Serial.print(F("["));
    Serial.print(instance_id);
    Serial.print(F("]"));
    Serial.print(F(" to "));
    Serial.println(filename);
#endif

    AudioNoInterrupts();
    SD.begin();
    SD.remove(filename);
    json = SD.open(filename, FILE_WRITE);
    if (json) {
      data_json["bank"] = configuration.dexed[instance_id].bank;
      data_json["voice"] = configuration.dexed[instance_id].voice;
      data_json["lowest_note"] = configuration.dexed[instance_id].lowest_note;
      data_json["highest_note"] = configuration.dexed[instance_id].highest_note;
      data_json["transpose"] = configuration.dexed[instance_id].transpose;
      data_json["tune"] = configuration.dexed[instance_id].tune;
      data_json["sound_intensity"] = configuration.dexed[instance_id].sound_intensity;
      data_json["pan"] = configuration.dexed[instance_id].pan;
      data_json["polyphony"] = configuration.dexed[instance_id].polyphony;
      data_json["velocity_level"] = configuration.dexed[instance_id].velocity_level;
      data_json["monopoly"] = configuration.dexed[instance_id].monopoly;
      data_json["monopoly"] = configuration.dexed[instance_id].monopoly;
      data_json["note_refresh"] = configuration.dexed[instance_id].note_refresh;
      data_json["pb_range"] = configuration.dexed[instance_id].pb_range;
      data_json["pb_step"] = configuration.dexed[instance_id].pb_step;
      data_json["mw_range"] = configuration.dexed[instance_id].mw_range;
      data_json["mw_assign"] = configuration.dexed[instance_id].mw_assign;
      data_json["mw_mode"] = configuration.dexed[instance_id].mw_mode;
      data_json["fc_range"] = configuration.dexed[instance_id].fc_range;
      data_json["fc_assign"] = configuration.dexed[instance_id].fc_assign;
      data_json["fc_mode"] = configuration.dexed[instance_id].fc_mode;
      data_json["bc_range"] = configuration.dexed[instance_id].bc_range;
      data_json["bc_assign"] = configuration.dexed[instance_id].bc_assign;
      data_json["bc_mode"] = configuration.dexed[instance_id].bc_mode;
      data_json["at_range"] = configuration.dexed[instance_id].at_range;
      data_json["at_assign"] = configuration.dexed[instance_id].at_assign;
      data_json["at_mode"] = configuration.dexed[instance_id].at_mode;
      data_json["portamento_mode"] = configuration.dexed[instance_id].portamento_mode;
      data_json["portamento_glissando"] = configuration.dexed[instance_id].portamento_glissando;
      data_json["portamento_time"] = configuration.dexed[instance_id].portamento_time;
      data_json["op_enabled"] = configuration.dexed[instance_id].op_enabled;
      data_json["midi_channel"] = configuration.dexed[instance_id].midi_channel;
      data_json["engine"] = configuration.dexed[instance_id].engine;

#if defined(DEBUG) && defined(DEBUG_SHOW_JSON)
      Serial.println(F("Write JSON data:"));
      serializeJsonPretty(data_json, Serial);
      Serial.println();
#endif
      serializeJsonPretty(data_json, json);
      json.close();
      AudioInterrupts();

      return (true);
    }
    json.close();
  } else {
#ifdef DEBUG
    Serial.print(F("E : Cannot open "));
    Serial.print(filename);
    Serial.println(F(" on SD."));
#endif
  }

  AudioInterrupts();
  return (false);
}

/******************************************************************************
   SD FX
 ******************************************************************************/
bool load_sd_fx_json(uint8_t number) {
  number = constrain(number, PERFORMANCE_NUM_MIN, PERFORMANCE_NUM_MAX);

  if (sd_card > 0) {
    File json;
    StaticJsonDocument<JSON_BUFFER_SIZE> data_json;
    char filename[CONFIG_FILENAME_LEN];
    snprintf_P(filename, sizeof(filename), PSTR("/%s/%d/%s.json"), PERFORMANCE_CONFIG_PATH, number, FX_CONFIG_NAME);

    // first check if file exists...
    AudioNoInterrupts();
    if (SD.exists(filename)) {
      // ... and if: load
#ifdef DEBUG
      Serial.print(F("Found fx configuration ["));
      Serial.print(filename);
      Serial.println(F("]... loading..."));
#endif
      json = SD.open(filename);
      if (json) {
        deserializeJson(data_json, json);

        json.close();
        AudioInterrupts();

#if defined(DEBUG) && defined(DEBUG_SHOW_JSON)
        Serial.println(F("Read JSON data:"));
        serializeJsonPretty(data_json, Serial);
        Serial.println();
#endif
        for (uint8_t i = 0; i < MAX_DEXED; i++) {
          configuration.fx.filter_cutoff[i] = data_json["filter_cutoff"][i];
          configuration.fx.filter_resonance[i] = data_json["filter_resonance"][i];
          configuration.fx.chorus_frequency[i] = data_json["chorus_frequency"][i];
          configuration.fx.chorus_waveform[i] = data_json["chorus_waveform"][i];
          configuration.fx.chorus_depth[i] = data_json["chorus_depth"][i];
          configuration.fx.chorus_level[i] = data_json["chorus_level"][i];
          configuration.fx.delay_time[i] = data_json["delay_time"][i];
          configuration.fx.delay_feedback[i] = data_json["delay_feedback"][i];
          configuration.fx.delay_level[i] = data_json["delay_level"][i];
          configuration.fx.reverb_send[i] = data_json["reverb_send"][i];
        }
        configuration.fx.reverb_roomsize = data_json["reverb_roomsize"];
        configuration.fx.reverb_damping = data_json["reverb_damping"];
        configuration.fx.reverb_lowpass = data_json["reverb_lowpass"];
        configuration.fx.reverb_lodamp = data_json["reverb_lodamp"];
        configuration.fx.reverb_hidamp = data_json["reverb_hidamp"];
        configuration.fx.reverb_diffusion = data_json["reverb_diffusion"];
        configuration.fx.reverb_level = data_json["reverb_level"];
        configuration.fx.eq_1 = data_json["eq_1"];
        configuration.fx.eq_2 = data_json["eq_2"];
        configuration.fx.eq_3 = data_json["eq_3"];
        configuration.fx.eq_4 = data_json["eq_4"];
        configuration.fx.eq_5 = data_json["eq_5"];
        configuration.fx.eq_6 = data_json["eq_6"];
        configuration.fx.eq_7 = data_json["eq_7"];
        configuration.fx.ep_chorus_frequency = data_json["ep_chorus_frequency"];
        configuration.fx.ep_chorus_waveform = data_json["ep_chorus_waveform"];
        configuration.fx.ep_chorus_depth = data_json["ep_chorus_depth"];
        configuration.fx.ep_chorus_level = data_json["ep_chorus_level"];
        configuration.fx.ep_reverb_send = data_json["ep_reverb_send"];

        check_configuration_fx();
        set_fx_params();

        return (true);
      }
#ifdef DEBUG
      else {
        Serial.print(F("E : Cannot open "));
        Serial.print(filename);
        Serial.println(F(" on SD."));
      }
    } else {
      Serial.print(F("No "));
      Serial.print(filename);
      Serial.println(F(" available."));
#endif
    }
  }

  AudioInterrupts();
  return (false);
}

bool save_sd_fx_json(uint8_t number) {
  char filename[CONFIG_FILENAME_LEN];

  number = constrain(number, PERFORMANCE_NUM_MIN, PERFORMANCE_NUM_MAX);

  save_sd_drumsettings_json(number);
  if (sd_card > 0) {
    File json;
    StaticJsonDocument<JSON_BUFFER_SIZE> data_json;
    snprintf_P(filename, sizeof(filename), PSTR("/%s/%d/%s.json"), PERFORMANCE_CONFIG_PATH, number, FX_CONFIG_NAME);

#ifdef DEBUG
    Serial.print(F("Saving fx config "));
    Serial.print(number);
    Serial.print(F(" to "));
    Serial.println(filename);
#endif

    AudioNoInterrupts();
    SD.begin();
    SD.remove(filename);
    json = SD.open(filename, FILE_WRITE);
    if (json) {
      for (uint8_t i = 0; i < MAX_DEXED; i++) {
        data_json["filter_cutoff"][i] = configuration.fx.filter_cutoff[i];
        data_json["filter_resonance"][i] = configuration.fx.filter_resonance[i];
        data_json["chorus_frequency"][i] = configuration.fx.chorus_frequency[i];
        data_json["chorus_waveform"][i] = configuration.fx.chorus_waveform[i];
        data_json["chorus_depth"][i] = configuration.fx.chorus_depth[i];
        data_json["chorus_level"][i] = configuration.fx.chorus_level[i];
        data_json["delay_time"][i] = configuration.fx.delay_time[i];
        data_json["delay_feedback"][i] = configuration.fx.delay_feedback[i];
        data_json["delay_level"][i] = configuration.fx.delay_level[i];
        data_json["reverb_send"][i] = configuration.fx.reverb_send[i];
      }
      data_json["reverb_roomsize"] = configuration.fx.reverb_roomsize;
      data_json["reverb_damping"] = configuration.fx.reverb_damping;
      data_json["reverb_lowpass"] = configuration.fx.reverb_lowpass;
      data_json["reverb_lodamp"] = configuration.fx.reverb_lodamp;
      data_json["reverb_hidamp"] = configuration.fx.reverb_hidamp;
      data_json["reverb_diffusion"] = configuration.fx.reverb_diffusion;
      data_json["reverb_level"] = configuration.fx.reverb_level;
      data_json["eq_1"] = configuration.fx.eq_1;
      data_json["eq_2"] = configuration.fx.eq_2;
      data_json["eq_3"] = configuration.fx.eq_3;
      data_json["eq_4"] = configuration.fx.eq_4;
      data_json["eq_5"] = configuration.fx.eq_5;
      data_json["eq_6"] = configuration.fx.eq_6;
      data_json["eq_7"] = configuration.fx.eq_7;
      data_json["ep_chorus_frequency"] = configuration.fx.ep_chorus_frequency;
      data_json["ep_chorus_waveform"] = configuration.fx.ep_chorus_waveform;
      data_json["ep_chorus_depth"] = configuration.fx.ep_chorus_depth;
      data_json["ep_chorus_level"] = configuration.fx.ep_chorus_level;
      data_json["ep_reverb_send"] = configuration.fx.ep_reverb_send;

#if defined(DEBUG) && defined(DEBUG_SHOW_JSON)
      Serial.println(F("Write JSON data:"));
      serializeJsonPretty(data_json, Serial);
      Serial.println();
#endif
      serializeJsonPretty(data_json, json);
      json.close();
      AudioInterrupts();
      return (true);
    }
    json.close();
  } else {
#ifdef DEBUG
    Serial.print(F("E : Cannot open "));
    Serial.print(filename);
    Serial.println(F(" on SD."));
#endif
  }

  AudioInterrupts();
  return (false);
}

/******************************************************************************
   SD EPIANO
 ******************************************************************************/
bool load_sd_epiano_json(uint8_t number) {
  number = constrain(number, PERFORMANCE_NUM_MIN, PERFORMANCE_NUM_MAX);

  if (sd_card > 0) {
    File json;
    StaticJsonDocument<JSON_BUFFER_SIZE> data_json;
    char filename[CONFIG_FILENAME_LEN];
    snprintf_P(filename, sizeof(filename), PSTR("/%s/%d/%s.json"), PERFORMANCE_CONFIG_PATH, number, EPIANO_CONFIG_NAME);

    // first check if file exists...
    AudioNoInterrupts();
    if (SD.exists(filename)) {
      // ... and if: load
#ifdef DEBUG
      Serial.print(F("Found epiano configuration ["));
      Serial.print(filename);
      Serial.println(F("]... loading..."));
#endif
      json = SD.open(filename);
      if (json) {
        deserializeJson(data_json, json);

        json.close();
        AudioInterrupts();

#if defined(DEBUG) && defined(DEBUG_SHOW_JSON)
        Serial.println(F("Read JSON data:"));
        serializeJsonPretty(data_json, Serial);
        Serial.println();
#endif
        configuration.epiano.decay = data_json["decay"];
        configuration.epiano.release = data_json["release"];
        configuration.epiano.hardness = data_json["hardness"];
        configuration.epiano.treble = data_json["treble"];
        configuration.epiano.pan_tremolo = data_json["pan_tremolo"];
        configuration.epiano.pan_lfo = data_json["pan_lf"];
        configuration.epiano.velocity_sense = data_json["velocity"];
        configuration.epiano.stereo = data_json["stereo"];
        configuration.epiano.polyphony = data_json["polyphony"];
        configuration.epiano.tune = data_json["tune"];
        configuration.epiano.detune = data_json["detune"];
        configuration.epiano.overdrive = data_json["overdrive"];
        configuration.epiano.lowest_note = data_json["lowest_note"];
        configuration.epiano.highest_note = data_json["highest_note"];
        configuration.epiano.transpose = data_json["transpose"];
        configuration.epiano.sound_intensity = data_json["sound_intensity"];
        configuration.epiano.pan = data_json["pan"];
        configuration.epiano.midi_channel = data_json["midi_channel"];

        check_configuration_epiano();
        set_epiano_params();        

        return (true);
      }
#ifdef DEBUG
      else {
        Serial.print(F("E : Cannot open "));
        Serial.print(filename);
        Serial.println(F(" on SD."));
      }
    } else {
      Serial.print(F("No "));
      Serial.print(filename);
      Serial.println(F(" available."));
#endif
    }
  }

  AudioInterrupts();
  return (false);
}

bool save_sd_epiano_json(uint8_t number) {
  char filename[CONFIG_FILENAME_LEN];

  number = constrain(number, PERFORMANCE_NUM_MIN, PERFORMANCE_NUM_MAX);

  if (sd_card > 0) {
    File json;
    StaticJsonDocument<JSON_BUFFER_SIZE> data_json;
    snprintf_P(filename, sizeof(filename), PSTR("/%s/%d/%s.json"), PERFORMANCE_CONFIG_PATH, number, EPIANO_CONFIG_NAME);

#ifdef DEBUG
    Serial.print(F("Saving epiano config "));
    Serial.print(number);
    Serial.print(F(" to "));
    Serial.println(filename);
#endif

    AudioNoInterrupts();
    SD.begin();
    SD.remove(filename);
    json = SD.open(filename, FILE_WRITE);
    if (json) {
      data_json["decay"] = configuration.epiano.decay;
      data_json["release"] = configuration.epiano.release;
      data_json["hardness"] = configuration.epiano.hardness;
      data_json["treble"] = configuration.epiano.treble;
      data_json["pan_tremolo"] = configuration.epiano.pan_tremolo;
      data_json["pan_lfo"] = configuration.epiano.pan_lfo;
      data_json["velocity_sense"] = configuration.epiano.velocity_sense;
      data_json["stereo"] = configuration.epiano.stereo;
      data_json["polyphony"] = configuration.epiano.polyphony;
      data_json["tune"] = configuration.epiano.tune;
      data_json["detune"] = configuration.epiano.detune;
      data_json["overdrive"] = configuration.epiano.overdrive;
      data_json["lowest_note"] = configuration.epiano.lowest_note;
      data_json["highest_note"] = configuration.epiano.highest_note;
      data_json["transpose"] = configuration.epiano.transpose;
      data_json["sound_intensity"] = configuration.epiano.sound_intensity;
      data_json["pan"] = configuration.epiano.pan;
      data_json["midi_channel"] = configuration.epiano.midi_channel;

#if defined(DEBUG) && defined(DEBUG_SHOW_JSON)
      Serial.println(F("Write JSON data:"));
      serializeJsonPretty(data_json, Serial);
      Serial.println();
#endif
      serializeJsonPretty(data_json, json);
      json.close();
      AudioInterrupts();
      return (true);
    }
    json.close();
  } else {
#ifdef DEBUG
    Serial.print(F("E : Cannot open "));
    Serial.print(filename);
    Serial.println(F(" on SD."));
#endif
  }

  AudioInterrupts();
  return (false);
}

/******************************************************************************
   SD SYS
 ******************************************************************************/
bool load_sd_sys_json(void) {
  if (sd_card > 0) {
    File json;
    StaticJsonDocument<JSON_BUFFER_SIZE> data_json;
    char filename[CONFIG_FILENAME_LEN];
    snprintf_P(filename, sizeof(filename), PSTR("/%s.json"), SYS_CONFIG_NAME);

    // first check if file exists...
    AudioNoInterrupts();
    if (SD.exists(filename)) {
      // ... and if: load
#ifdef DEBUG
      Serial.println(F("Found sys configuration"));
#endif
      json = SD.open(filename);
      if (json) {
        deserializeJson(data_json, json);

        json.close();
        AudioInterrupts();

#if defined(DEBUG) && defined(DEBUG_SHOW_JSON)
        Serial.println(F("Read JSON data:"));
        serializeJsonPretty(data_json, Serial);
        Serial.println();
#endif

        configuration.sys.vol = data_json["vol"];
        configuration.sys.mono = data_json["mono"];
        configuration.sys.soft_midi_thru = data_json["soft_midi_thru"];
        configuration.sys.performance_number = data_json["performance_number"];
        configuration.sys.favorites = data_json["favorites"];
        configuration.sys.load_at_startup = data_json["load_at_startup"];

        check_configuration_sys();
        set_sys_params();

        return (true);
      }
#ifdef DEBUG
      else {
        Serial.print(F("E : Cannot open "));
        Serial.print(filename);
        Serial.println(F(" on SD."));
      }
    } else {
      Serial.print(F("No "));
      Serial.print(filename);
      Serial.println(F(" available."));
#endif
    }
  }

  AudioInterrupts();
  return (false);
}

bool save_sd_sys_json(void) {
  char filename[CONFIG_FILENAME_LEN];

  if (sd_card > 0) {
    File json;
    StaticJsonDocument<JSON_BUFFER_SIZE> data_json;
    snprintf_P(filename, sizeof(filename), PSTR("/%s.json"), SYS_CONFIG_NAME);

#ifdef DEBUG
    Serial.print(F("Saving sys config to "));
    Serial.println(filename);
#endif

    AudioNoInterrupts();
    SD.begin();
    SD.remove(filename);
    json = SD.open(filename, FILE_WRITE);
    if (json) {
      data_json["vol"] = configuration.sys.vol;
      data_json["mono"] = configuration.sys.mono;
      data_json["soft_midi_thru"] = configuration.sys.soft_midi_thru;
      data_json["performance_number"] = configuration.sys.performance_number;
      data_json["favorites"] = configuration.sys.favorites;
      data_json["load_at_startup"] = configuration.sys.load_at_startup;

#if defined(DEBUG) && defined(DEBUG_SHOW_JSON)
      Serial.println(F("Write JSON data:"));
      serializeJsonPretty(data_json, Serial);
      Serial.println();
#endif
      serializeJsonPretty(data_json, json);
      json.close();
      AudioInterrupts();
      save_sys_flag = false;
      return (true);
    }
    json.close();
  } else {
#ifdef DEBUG
    Serial.print(F("E : Cannot open "));
    Serial.print(filename);
    Serial.println(F(" on SD."));
#endif
  }

  AudioInterrupts();
  return (false);
}

bool save_sd_performance_json(uint8_t number) {
  char filename[CONFIG_FILENAME_LEN];

  number = constrain(number, PERFORMANCE_NUM_MIN, PERFORMANCE_NUM_MAX);

  dac_mute();

  AudioNoInterrupts();

  display.show(1, 13, 3, "1/4");
  check_performance_directory(number);

#ifdef DEBUG
  Serial.print(F("Write performance config "));
  Serial.println(number);
#endif

  display.show(1, 13, 3, "2/4");
  save_sd_fx_json(number);
  display.show(1, 13, 3, "3/4");
  save_sd_epiano_json(number);

  for (uint8_t i = 0; i < MAX_DEXED; i++) {
    snprintf_P(filename, sizeof(filename), PSTR("/%s/%d/%s%d.json"), PERFORMANCE_CONFIG_PATH, number, VOICE_CONFIG_NAME, i);
#ifdef DEBUG
    Serial.print(F("Write Voice-Config"));
    Serial.println(filename);
#endif
    display.show(1, 13, 3, "4/4");
    save_sd_voiceconfig_json(number, i);
  }

  if (sd_card > 0) {
    File json;
    StaticJsonDocument<JSON_BUFFER_SIZE> data_json;
    snprintf_P(filename, sizeof(filename), PSTR("/%s/%d/%s.json"), PERFORMANCE_CONFIG_PATH, number, PERFORMANCE_CONFIG_NAME);
#ifdef DEBUG
    Serial.print(F("Saving performance config "));
    Serial.print(number);
    Serial.print(F(" to "));
    Serial.println(filename);
#endif

    SD.remove(filename);
    json = SD.open(filename, FILE_WRITE);
    if (json) {
      data_json["name"] = configuration.performance.name;
      serializeJsonPretty(data_json, json);
      json.close();
      AudioInterrupts();
      dac_unmute();
      return (true);
    }
    json.close();
    AudioInterrupts();
  }
#ifdef DEBUG
  else {
    Serial.print(F("E : Cannot open "));
    Serial.print(filename);
    Serial.println(F(" on SD."));
    AudioInterrupts();
  }
#endif

  return (false);
}

bool check_performance_directory(uint8_t number) {
  char dir[CONFIG_FILENAME_LEN];

  if (sd_card > 0) {
    snprintf_P(dir, sizeof(dir), PSTR("/%s/%d"), PERFORMANCE_CONFIG_PATH, number);

    AudioNoInterrupts();
    SD.begin();
    if (!SD.exists(dir)) {
#ifdef DEBUG
      if (SD.mkdir(dir)) {
        Serial.print(F("Creating directory "));
        Serial.println(dir);
      } else {
        Serial.print(F("E: Cannot create "));
        Serial.println(dir);
        AudioInterrupts();
        return (false);
      }
#else
      SD.mkdir(dir);
#endif
    }
    AudioInterrupts();
    return (true);
  }
#ifdef DEBUG
  else {
    Serial.println(F("E: SD card not available"));
  }
#endif
  return (false);
}

void get_sd_performance_name_json(uint8_t number, char* name, uint8_t len) {
  number = constrain(number, PERFORMANCE_NUM_MIN, PERFORMANCE_NUM_MAX);
  if (sd_card > 0) {
    File json;
    StaticJsonDocument<JSON_BUFFER_SIZE> data_json;
    char filename[CONFIG_FILENAME_LEN];

    snprintf_P(filename, sizeof(filename), PSTR("/%s/%d/%s.json"), PERFORMANCE_CONFIG_PATH, number, PERFORMANCE_CONFIG_NAME);

    // first check if file exists...
    AudioNoInterrupts();
    if (SD.exists(filename)) {
      // ... and if: load

      json = SD.open(filename);
      if (json) {
        deserializeJson(data_json, json);

        json.close();
        AudioInterrupts();
      }

      strlcpy(name, data_json["name"] | "NoName", len);

#ifdef DEBUG
      Serial.print(F("Get performance name for "));
      Serial.print(number);
      Serial.print(F(": ["));
      Serial.print(name);
      Serial.println("]");
#endif
    }
  }
}

bool load_sd_performance_json(uint8_t number) {

  get_sd_performance_name_json(number, configuration.performance.name, sizeof(configuration.performance.name));

  dac_mute();
  handleStop();
  number = constrain(number, PERFORMANCE_NUM_MIN, PERFORMANCE_NUM_MAX);
  AudioNoInterrupts();
  load_sd_fx_json(number);
  load_sd_epiano_json(number);
#if NUM_DRUMS > 0
  load_sd_drumsettings_json(number);
#endif

  if (sd_card > 0) {
    File json;
    StaticJsonDocument<JSON_BUFFER_SIZE> data_json;

    for (uint8_t instance_id = 0; instance_id < NUM_DEXED; instance_id++) {
#ifdef DEBUG
      Serial.print(F("Load Voice-Config "));
      Serial.println(instance_id + 1);
#endif
      load_sd_voiceconfig_json(number, instance_id);
      load_sd_voice(configuration.dexed[instance_id].bank, configuration.dexed[instance_id].voice, instance_id);
      MicroDexed[instance_id]->setGain(midi_volume_transform(map(configuration.dexed[instance_id].sound_intensity, SOUND_INTENSITY_MIN, SOUND_INTENSITY_MAX, 0, 127)));
      MicroDexed[instance_id]->panic();
    }

    dac_unmute();
    AudioInterrupts();

    return (true);
  }

  return (false);
}

bool check_sd_performance_exists(uint8_t number) {
  if (number < 0)
    return (false);

  number = constrain(number, PERFORMANCE_NUM_MIN, PERFORMANCE_NUM_MAX);
  AudioNoInterrupts();
  if (sd_card > 0) {
    char filename[CONFIG_FILENAME_LEN];

    snprintf_P(filename, sizeof(filename), PSTR("/%s/%d/%s.json"), PERFORMANCE_CONFIG_PATH, number, PERFORMANCE_CONFIG_NAME);

    // check if file exists...
    if (SD.exists(filename)) {
      AudioInterrupts();
      return (true);
    } else {
      AudioInterrupts();
      return (false);
    }
  } else {
    AudioInterrupts();
    return (false);
  }
}

/******************************************************************************
   HELPER FUNCTIONS
 ******************************************************************************/
bool get_sd_data(File sysex, uint8_t format, uint8_t* conf) {
  uint16_t n;
  int32_t bulk_checksum_calc = 0;
  int8_t bulk_checksum;

#ifdef DEBUG
  Serial.print(F("Reading "));
  Serial.print(sysex.size());
  Serial.println(F(" bytes."));
#endif

  AudioNoInterrupts();
  if (sysex.read() != 0xf0)  // check sysex start-byte
  {
#ifdef DEBUG
    Serial.println(F("E : SysEx start byte not found."));
#endif
    return (false);
  }
  if (sysex.read() != 0x67)  // check sysex vendor is unofficial SYSEX-ID for MicroDexed
  {
#ifdef DEBUG
    Serial.println(F("E : SysEx vendor not unofficial SYSEX-ID for MicroDexed."));
#endif
    return (false);
  }
  if (sysex.read() != format)  // check for sysex type
  {
#ifdef DEBUG
    Serial.println(F("E : SysEx type not found."));
#endif
    return (false);
  }
  sysex.seek(sysex.size() - 1);
  if (sysex.read() != 0xf7)  // check sysex end-byte
  {
#ifdef DEBUG
    Serial.println(F("E : SysEx end byte not found."));
#endif
    return (false);
  }

  sysex.seek(sysex.size() - 2);  // Bulk checksum
  bulk_checksum = sysex.read();

  sysex.seek(3);  // start of bulk data
  for (n = 0; n < sysex.size() - 6; n++) {
    uint8_t d = sysex.read();
    bulk_checksum_calc -= d;
#ifdef DEBUG
    Serial.print(F("SYSEX data read: 0x"));
    Serial.println(d, HEX);
#endif
  }
  bulk_checksum_calc &= 0x7f;

  if (int8_t(bulk_checksum_calc) != bulk_checksum) {
#ifdef DEBUG
    Serial.print(F("E : Bulk checksum mismatch : 0x"));
    Serial.print(int8_t(bulk_checksum_calc), HEX);
    Serial.print(F(" != 0x"));
    Serial.println(bulk_checksum, HEX);
#endif
    return (false);
  }
#ifdef DEBUG
  else {
    Serial.print(F("Bulk checksum : 0x"));
    Serial.print(int8_t(bulk_checksum_calc), HEX);
    Serial.print(F(" [0x"));
    Serial.print(bulk_checksum, HEX);
    Serial.println(F("]"));
  }
#endif

  sysex.seek(3);  // start of bulk data
  for (n = 0; n < sysex.size() - 6; n++) {
    uint8_t d = sysex.read();
    *(conf++) = d;
  }
  AudioInterrupts();

#ifdef DEBUG
  Serial.println(F("SD data loaded."));
#endif

  return (true);
}

bool write_sd_data(File sysex, uint8_t format, uint8_t* data, uint16_t len) {
#ifdef DEBUG
  Serial.print(F("Storing SYSEX format 0x"));
  Serial.print(format, HEX);
  Serial.print(F(" with length of "));
  Serial.print(len, DEC);
  Serial.println(F(" bytes."));
#endif

  // write sysex start
  AudioNoInterrupts();
  sysex.write(0xf0);
#ifdef DEBUG
  Serial.println(F("Write SYSEX start:    0xf0"));
#endif
  // write sysex vendor is unofficial SYSEX-ID for MicroDexed
  sysex.write(0x67);
#ifdef DEBUG
  Serial.println(F("Write SYSEX vendor:   0x67"));
#endif
  // write sysex format number
  sysex.write(format);
#ifdef DEBUG
  Serial.print(F("Write SYSEX format:   0x"));
  Serial.println(format, HEX);
#endif
  // write data
  sysex.write(data, len);
#ifdef DEBUG
  for (uint16_t i = 0; i < len; i++) {
    Serial.print(F("Write SYSEX data:     0x"));
    Serial.println(data[i], HEX);
  }
#endif
  // write checksum
  sysex.write(calc_checksum(data, len));
#ifdef DEBUG
  uint8_t checksum = calc_checksum(data, len);
  sysex.write(checksum);
  Serial.print(F("Write SYSEX checksum: 0x"));
  Serial.println(checksum, HEX);
#endif
  // write sysex end
  sysex.write(0xf7);
  AudioInterrupts();

#ifdef DEBUG
  Serial.println(F("Write SYSEX end:      0xf7"));
#endif

  return (true);
}

uint8_t calc_checksum(uint8_t* data, uint16_t len) {
  int32_t bulk_checksum_calc = 0;

  for (uint16_t n = 0; n < len; n++)
    bulk_checksum_calc -= data[n];

  return (bulk_checksum_calc & 0x7f);
}

void strip_extension(const char* s, char* target, uint8_t len) {
  char tmp[CONFIG_FILENAME_LEN];
  char* token;

  strlcpy(tmp, s, len);
  token = strtok(tmp, ".");
  if (token == NULL)
    strlcpy(target, "*ERROR*", len);
  else
    strlcpy(target, token, len);

  target[len] = '\0';
}

bool get_bank_name(uint8_t b, char* name, uint8_t len) {
  File sysex;

  if (sd_card > 0) {
    char bankdir[4];
    File entry;

    memset(name, 0, len);

    snprintf_P(bankdir, sizeof(bankdir), PSTR("/%d"), b);

    // try to open directory
    sysex = SD.open(bankdir);
    if (!sysex)
      return (false);

    do {
      entry = sysex.openNextFile();
    } while (entry.isDirectory());

    if (entry.isDirectory()) {
      entry.close();
      sysex.close();
      return (false);
    }

    strip_extension(entry.name(), name, len);

#ifdef DEBUG
    Serial.print(F("Found bank-name ["));
    Serial.print(name);
    Serial.print(F("] for bank ["));
    Serial.print(b);
    Serial.println(F("]"));
#endif

    entry.close();
    sysex.close();

    return (true);
  }

  return (false);
}

bool get_voice_name(uint8_t b, uint8_t v, char* name, uint8_t len) {
  File sysex;

  if (sd_card > 0) {
    char bank_name[BANK_NAME_LEN];
    char filename[FILENAME_LEN];

    b = constrain(b, 0, MAX_BANKS - 1);
    v = constrain(v, 0, MAX_VOICES - 1);

    get_bank_name(b, bank_name, sizeof(bank_name));
    snprintf_P(filename, sizeof(filename), PSTR("/%d/%s.syx"), b, bank_name);
#ifdef DEBUG
    Serial.print(F("Reading voice-name from ["));
    Serial.print(filename);
    Serial.println(F("]"));
#endif

    // try to open directory
    AudioNoInterrupts();
    sysex = SD.open(filename);
    if (!sysex)
      return (false);

    memset(name, 0, len);
    sysex.seek(124 + (v * 128));
    sysex.read(name, min(len, 10));

#ifdef DEBUG
    Serial.print(F("Found voice-name ["));
    Serial.print(name);
    Serial.print(F("] for bank ["));
    Serial.print(b);
    Serial.print(F("] and voice ["));
    Serial.print(v);
    Serial.println(F("]"));
#endif

    sysex.close();
    AudioInterrupts();

    return (true);
  }

  return (false);
}

bool get_voice_by_bank_name(uint8_t b, const char* bank_name, uint8_t v, char* voice_name, uint8_t len) {
  File sysex;

  if (sd_card > 0) {
    char filename[FILENAME_LEN];

    snprintf_P(filename, sizeof(filename), PSTR("/%d/%s.syx"), b, bank_name);
#ifdef DEBUG
    Serial.print(F("Reading voice-name from ["));
    Serial.print(filename);
    Serial.println(F("]"));
#endif

    // try to open directory
    AudioNoInterrupts();
    sysex = SD.open(filename);
    if (!sysex)
      return (false);

    memset(voice_name, 0, len);
    sysex.seek(124 + (v * 128));
    sysex.read(voice_name, min(len, 10));

#ifdef DEBUG
    Serial.print(F("Found voice-name ["));
    Serial.print(voice_name);
    Serial.print(F("] for bank ["));
    Serial.print(b);
    Serial.print(F("|"));
    Serial.print(bank_name);
    Serial.print(F("] and voice ["));
    Serial.print(v);
    Serial.println(F("]"));
#endif

    sysex.close();
    AudioInterrupts();

    return (true);
  }

  return (false);
}

void string_toupper(char* s) {
  while (*s) {
    *s = toupper((unsigned char)*s);
    s++;
  }
}