/*
 *  The preset manager saves and loads the parameters in the
 *  patch/subpatch it appears in or all parameters in all sub patches
 *  depending on the selected save mode, "Global" or "SubPatch".
 *  In SubPatch mode, each sub patch may need their own preset manager
 *  object to handle its parameters. Choose save mode and placement
 *  of preset manager objects depending on what you want saved.
 *
 *  There are 4 ways to load and save presets:
 *    1 - Using MIDI by sending standard program change messages.
 *    2 - Using MIDI by sending designated CCs set the preset number
 *        and trigger load and save operations.
 *    3 - Using the preset number spinbox and load and save buttons
 *        on the module for managing presets from the patch windows.
 *    3 - Using the preset, load and save inputs to set
 *        the preset number and trigger load and save operations.
 *
 *  The savemode menu select the scope of the save opration.
 *
 *  The pgmchange menu enables or disables MIDI program changes.
 *
 *  The channel spinbox sets the MIDI channel that will
 *  be used for MIDI control.
 *
 *  The presetcc, loadcc and savecc spinboxes selects the MIDI CC
 *  numbers used for controlling the preset manager. The preset number
 *  to load or save is set with presetcc, the load action is triggered
 *  by loadcc and the save action is triggered by savecc. Set the CC
 *  numbers to -1 to disable their corresponding functions.
 *
 *  The autoload spinbox selects a preset number which will be loaded
 *  automatically when the patch starts. Set autoload to -1 for no preset
 *  to be loaded.
 *
 *  The preset spinbox, and load and save buttons control the
 *  load and save operations directly from a patch window.
 *
 *  The preset output and the save and load pulse outputs can
 *  be used to chain save/load actions to sub patches by connecting
 *  to the corresponding inputs of other preset managers.
 *  If managing presets by MIDI only, the preset managers
 *  (in the various sub patches) that listens to MIDI does
 *  not need to be chained together. When a preset manager gets
 *  a change message via MIDI, it will not send save/load pulses
 *  to avoid multiple load/save triggers.
 *
 *  The filenames are constructed of a prefix, taken form the prefix
 *  string input, a three digit zero padded preset number and a file
 *  extension. The preset files are saved in the SD card directory of
 *  the current patch. So a preset filename looks like e.g.:
 *    0:/my_patch/foo001.pst
 *
 *  This means there are 1000 preset slots, although only the first 128
 *  can be accessed via MIDI (for now).
 *
 *  If a patch has multiple preset managers throughout its sub patches,
 *  each preset manager needs a unique string for the prefix. This allows
 *  each sub patch to save its parameters to separate files that can be
 *  reloaded later by the same sub patch in a different context.
 *  As an example, saving preset number 123 for "my_patch",
 *  containing two preset managers with the prefixes "syn" and "echo",
 *  results in the following files being created:
 *    0:/my_patch/syn123.pst
 *    0:/my_patch/echo123.pst
 *
 *  The file format consist of a string of 32 bit words, with a 3 word header:
 *    word 0   =>  header, "PRSx", file type identifier string, where x is the
 * version word 1   =>  header, save mode, 0 = global mode and 1 = sub patch
 * mode word 2   =>  header, number of parameters word 3   =>  first parameter
 * name hash word 4   =>  first parameter value
 *    ..
 *    word N   =>  last parameter name hash
 *    word N+1 =>  last parameter value
 *
 *  Possible workaround for global parameter access (see macro
 * USE_PATCHES_FILE): When using a patch parent table (in an SD card file if it
 * has to be so, using a preset_manager master with preset_slave modules in the
 * sub patches), the parameters will be grouped by sub patch:
 *
 *    word 0   =>  header, "PRSx", file type identifier string, where x is the
 * version word 1   =>  header, save mode, 0 = global mode and 1 = sub patch
 * mode, 2 = patch-parent-table? word 3   =>  header, number of patches word 4
 * =>  first patch header, patch id word 5   =>  first patch header, number of
 * parameters for this patch word 6   =>  first patch, first parameter name hash
 *    word 7   =>  first patch, first parameter value
 *    ..
 *    word N   =>  first patch, last parameter name hash
 *    word N+1 =>  first patch, last parameter value
 *    word N+2 =>  second patch header, patch id
 *    word N+3 =>  second patch header, number of parameters for this patch
 *    ...
 *
 *  Possible TBIs:
 *
 *   - Avoiding audio glitches by calling codec_clearbuffer() before save/load
 * operations
 *   - Avoiding audio glitches by providing a gain coefficiant outlet with fade
 * in/out before and after save/load operations (DONE, SEE: attr_volfade)
 *   - Much faster loading by scanning the directory and pre-loading all presets
 * into DRAM on module startup and preset save operations. Challenges: memory
 * mamangement, sparse preset sets.
 *   - Polyphonic parameter access, ref. methods from xpatch.cpp:
 *
 *        static voice * getVoices(void){
 *             static voice v[3];
 *            return v;
 *        }
 *        static void PropagateToVoices(ParameterExchange_t *origin) {
 *              ParameterExchange_t *pex = (ParameterExchange_t
 * *)origin->finalvalue; int vi; for (vi = 0; vi < 3; vi++) {
 *                PExParameterChange(pex,origin->modvalue,0xFFFFFFEE);
 *                  pex = (ParameterExchange_t *)((int)pex + sizeof(voice)); //
 * dirty trick...
 *              }
 *        }
 *
 *
 *        int vi; for(vi=0;vi<3;vi++) {
 *           voice *v = &getVoices()[vi];
 *           v->polyIndex = vi;
 *           v->common = this;
 *           v->Init(&getVoices()[vi]);
 *           notePlaying[vi]=0;
 *           voicePriority[vi]=0;
 *           for (j = 0; j < v->NPEXCH; j++) {
 *              v->PExch[j].value = 0;
 *              v->PExch[j].modvalue = 0;
 *           }
 *        }
 */

//#define DEBUGF LogTextMessage
#define DEBUGF(...)                                                            \
  {}

//#define USE_PATCHES_FILE

//#define USE_NOOF_PARAMS_TEST

int32_t start_sequence;
int32_t preset_no;
int32_t preset_candidate;
int32_t midi_preset_no;
int32_t old_inlet_save;
int32_t old_param_save;
int32_t old_inlet_load;
int32_t old_param_load;
int32_t load_pulse;
int32_t save_pulse;
const char *magic_v2;
const char *suffix;
const char *prefix_copy;
int32_t gain_coeff;
#if attr_volfade < (1 << 27)
int32_t fade_rate;
int32_t save_load_state;
#endif

#ifdef USE_PATCHES_FILE
const char *patches_filename;
#endif

typedef struct _PresetFileHeader {
  char magic[4];
  int32_t savemode;
  int32_t n_params;
} PresetFileHeader;

enum {
  PRESET_MANAGER_SAVE_MODE_global = 0,
  PRESET_MANAGER_SAVE_MODE_subpatch = 1,
  PRESET_MANAGER_SAVE_MODE_subpatch_v1 = 2
} PRESET_MANAGER_SAVE_MODE;

#define PRESET_MANAGER_PE_SIGNAL_MASK 0xFFFD

enum {
  PRESET_MANAGER_SAVE_LOAD_STATE_idle = 0,
  PRESET_MANAGER_SAVE_LOAD_STATE_save,
  PRESET_MANAGER_SAVE_LOAD_STATE_load
} PRESET_MANAGER_SAVE_LOAD_STATE;

/*
 *  Constructs a filename to use
 */

void prepare_filename(char *filename, int buflen, const char *prefix,
                      int preset_no) {
  int offset = 0;
  if (prefix != NULL) {
    strncpy(filename, prefix, buflen);
    offset = strlen(filename);
  }
  if (buflen >= offset + 4) {
    filename[offset++] = '0' + (preset_no / 100) % 10;
    filename[offset++] = '0' + (preset_no / 10) % 10;
    filename[offset++] = '0' + preset_no % 10;
    filename[offset] = 0;
  }
  strncpy(filename + offset, suffix, buflen - offset);
  filename[buflen - 1] = 0;
};

/*
 *  Handle file errors by reporting an clsing the file
 */

int file_error(FIL *FileObject, FRESULT err, const char *filename) {
  if (err != FR_OK)
    report_fatfs_error(err, filename);
  if (FileObject != NULL)
    f_close(FileObject);
  return -1;
}

/*
 *  Determines the number of global parameters to save or load.
 */

int get_noof_global_IPVP_params(void) {
  extern struct KeyValuePair *ObjectKvpRoot;
  extern struct KeyValuePair *ObjectKvps[];
  int n_params = 0;
  for (int i = 0; i < ObjectKvpRoot->apvp.length; i++) {
    if (ObjectKvps[i]->kvptype == KVP_TYPE_IPVP) {
      n_params++;
    }
  }
  return n_params;
}

/*
 *  Determines the number of patch parameters to save or load.
 *  These are the parameters that has a matching PExch[] address
 *  at both patch and global level.
 *  Some parameters may be skipped bacuse of an xpatch.cpp bug
 *  where some parameters don't get registered in the global table.
 */

int get_noof_patch_IPVP_params(void) {
  extern struct KeyValuePair *ObjectKvpRoot;
  extern struct KeyValuePair *ObjectKvps[];
  int n_params = 0;
  for (int patch_i = 0; patch_i < parent->NPEXCH; patch_i++) {
    for (int global_i = 0; global_i < ObjectKvpRoot->apvp.length; global_i++) {
      if (&parent->PExch[patch_i] == ObjectKvps[global_i]->ipvp.PEx)
      // if( ObjectKvps[global_i]->kvptype == KVP_TYPE_IPVP &&
      // &parent->PExch[patch_i] == ObjectKvps[global_i]->ipvp.PEx )
      {
        n_params++;
      }
    }
  }
  return n_params;
}

/*
 *  Find the parameter in the global ObjectKvps table which matches the given
 * name hash.
 */

int get_global_param_index(uint32_t name_hash) {
  extern struct KeyValuePair *ObjectKvpRoot;
  extern struct KeyValuePair *ObjectKvps[];
  for (int i = 0; i < ObjectKvpRoot->apvp.length; i++) {
    if (name_hash == CalcCRC32((uint8_t *)ObjectKvps[i]->keyname,
                               strlen(ObjectKvps[i]->keyname))) {
      return i;
    }
  }
  return -1;
}

/*
 *  Saves a preset to the SD card
 */

int preset_save(const char *prefix, int preset_no) {
  FRESULT err;
  FIL FileObject;
  char filename[64];

  prepare_filename(filename, 64, prefix, preset_no);
  err = f_open(&FileObject, filename, FA_WRITE | FA_CREATE_ALWAYS);
  if (err != FR_OK)
    return file_error(NULL, err, filename);

  DEBUGF("preset_manager::preset_save(): file open OK, name = '%s'", filename);

  if (attr_savemode == PRESET_MANAGER_SAVE_MODE_global) {
    err = preset_save_global(&FileObject);
    if (err == FR_OK)
      LogTextMessage("Global params saved to '%s'", filename);
  } else if (attr_savemode == PRESET_MANAGER_SAVE_MODE_subpatch) {
    err = preset_save_subpatch(&FileObject);
    if (err == FR_OK)
      LogTextMessage("Sub patch params saved to '%s'", filename);
  } else if (attr_savemode == PRESET_MANAGER_SAVE_MODE_subpatch_v1) {
    err = preset_save_subpatch_v1(&FileObject);
    if (err == FR_OK)
      LogTextMessage("Sub patch v1 params saved to '%s'", filename);
  }

  if (err != FR_OK) {
    return file_error(&FileObject, err, filename);
  }

  err = f_close(&FileObject);
  if (err != FR_OK) {
    return file_error(NULL, err, filename);
  }

  return 0;
}

FRESULT preset_save_header(FIL *FileObject, const char *magic, int32_t savemode,
                           int32_t n_params) {
  unsigned int bytes_written;
  FRESULT err;
  PresetFileHeader header;

  memcpy(header.magic, magic, sizeof(header.magic));
  header.savemode = savemode;
  header.n_params = n_params;
  return f_write(FileObject, (uint8_t *)&header, sizeof(PresetFileHeader),
                 &bytes_written);
}

FRESULT preset_save_global(FIL *FileObject) {
  FRESULT err;
  extern struct KeyValuePair *ObjectKvpRoot;
  extern struct KeyValuePair *ObjectKvps[];
  unsigned int bytes_written;
  int n_params;

  n_params = get_noof_global_IPVP_params();
  preset_save_header(FileObject, magic_v2, PRESET_MANAGER_SAVE_MODE_global,
                     n_params);
  if (err != FR_OK)
    return err;

  DEBUGF(
      "preset_manager::preset_save_global(): header written OK, n_params = %d",
      n_params);

  // Generate a hash of each parameter name and store (hash,value) pairs.
  for (int i = 0; i < ObjectKvpRoot->apvp.length; i++) {
    uint32_t pair[2];
    if (ObjectKvps[i]->kvptype == KVP_TYPE_IPVP) {
      if (ObjectKvps[i]->keyname != NULL) // Should probably never be NULL
        pair[0] = CalcCRC32((uint8_t *)ObjectKvps[i]->keyname,
                            strlen(ObjectKvps[i]->keyname));
      else
        pair[0] = 0;
      pair[1] = ObjectKvps[i]->ipvp.PEx->value;

      DEBUGF("preset_manager::preset_save_global(): name = '%s', hash= 0x%08x, "
             "value = 0x%08x",
             ObjectKvps[i]->keyname != NULL ? ObjectKvps[i]->keyname : "NULL",
             pair[0], ObjectKvps[i]->ipvp.PEx->value);

      err = f_write(FileObject, (uint8_t *)pair, sizeof(pair), &bytes_written);
      if (err != FR_OK)
        return err;
    }
  }
  return FR_OK;
};

FRESULT preset_save_subpatch(FIL *FileObject) {
  FRESULT err;
  extern struct KeyValuePair *ObjectKvpRoot;
  extern struct KeyValuePair *ObjectKvps[];
  unsigned int bytes_written;
  int n_params;
  int n_saved_params = 0;

  n_params = get_noof_patch_IPVP_params();
  err = preset_save_header(FileObject, magic_v2,
                           PRESET_MANAGER_SAVE_MODE_subpatch, n_params);
  if (err != FR_OK)
    return err;

  DEBUGF("preset_manager::preset_save_subpatch(): header written OK, n_params "
         "= %d",
         n_params);

  for (int patch_i = 0; patch_i < parent->NPEXCH; patch_i++) {
    for (int global_i = 0; global_i < ObjectKvpRoot->apvp.length; global_i++) {
      if (&parent->PExch[patch_i] ==
          ObjectKvps[global_i]
              ->ipvp
              .PEx /*&& ObjectKvps[global_i]->kvptype == KVP_TYPE_IPVP*/) {
        /*
         *  At this point we can save parent->PExch[patch_i] since it has a name
         *  in ObjectKvps[global_i] that we can take a hash of and store.
         *  On loading, we need to do this again, I.e. ensure thar the named
         * parameters PEx has an address that's a match in both the global
         * ObjectKvps[] and the sub patch parent->PExch[]
         */
        uint32_t pair[2];

        if (ObjectKvps[global_i]->keyname != NULL)
          pair[0] = CalcCRC32((uint8_t *)ObjectKvps[global_i]->keyname,
                              strlen(ObjectKvps[global_i]->keyname));
        else
          pair[0] = 0;
        pair[1] = ObjectKvps[global_i]->ipvp.PEx->value;

        DEBUGF("preset_manager::preset_save_subpatch(): name = '%s', hash= "
               "0x%08x, value = 0x%08x",
               ObjectKvps[global_i]->keyname != NULL
                   ? ObjectKvps[global_i]->keyname
                   : "NULL",
               pair[0], pair[1]);

        err =
            f_write(FileObject, (uint8_t *)pair, sizeof(pair), &bytes_written);
        if (err != FR_OK)
          return err;

        n_saved_params++;
        break;
      }
    }
  }
  if (n_saved_params < parent->NPEXCH) {
    LogTextMessage("%d non registered params were skipped!",
                   parent->NPEXCH - n_saved_params);
  }
  return FR_OK;
};

FRESULT preset_save_subpatch_v1(FIL *FileObject) {
  FRESULT err;
  unsigned int bytes_written;
  int32_t value;

  DEBUGF("preset_manager::preset_save_subpatch_v1(): file open OK, name = '%s'",
         filename);

  // Write header word 1: type and version identifier
  err = f_write(FileObject, (uint8_t *)"PRS1", 4, &bytes_written);
  if (err != FR_OK)
    return err;

  // Write header word 2: number of parameters
  value = parent->NPEXCH;
  err = f_write(FileObject, (uint8_t *)&value, sizeof(int32_t), &bytes_written);
  if (err != FR_OK)
    return err;

  DEBUGF("preset_manager::preset_save_subpatch_v1(): header written OK");

  for (int i = 0; i < parent->NPEXCH; i++) {
    value = parent->PExch[i].value;
    DEBUGF("preset_manager::preset_save_subpatch_v1(): 0x%08x", value);
    err =
        f_write(FileObject, (uint8_t *)&value, sizeof(int32_t), &bytes_written);
    if (err != FR_OK)
      return err;
  }
  return FR_OK;
};

/*
 *  Loads a preset from the SD card
 */

int preset_load(const char *prefix, int preset_no) {
  FRESULT err;
  FIL FileObject;
  PresetFileHeader header;
  unsigned int bytes_read;
  char filename[64];

  prepare_filename(filename, 64, prefix, preset_no);
  err = f_open(&FileObject, filename, FA_READ | FA_OPEN_EXISTING);
  if (err != FR_OK)
    return file_error(NULL, err, filename);

  DEBUGF("preset_manager::preset_load(): file opened OK, name = '%s'",
         filename);

  err = f_read(&FileObject, (uint8_t *)&header, sizeof(PresetFileHeader),
               &bytes_read);
  if (err != FR_OK)
    return file_error(&FileObject, err, filename);

  // Check id and version, call the right loader.
  for (int i = 0; i < 3; i++) {
    if (header.magic[i] != magic_v2[i]) {
      LogTextMessage("Preset file header id mismatch");
      return file_error(&FileObject, FR_OK, filename);
    }
  }
  int32_t file_version = header.magic[3];

  if (file_version == '1') {
    DEBUGF("preset_manager::preset_load(): loading file version 1");
    err = preset_load_subpatch_v1(&FileObject, &header);
    if (err == FR_OK)
      LogTextMessage("V1 Sub patch params loaded from '%s'", filename);
  } else if (file_version == '2') {
    DEBUGF("preset_manager::preset_load(): loading file version 2");
    if (header.savemode == PRESET_MANAGER_SAVE_MODE_global) {
      err = preset_load_global(&FileObject, &header);
      if (err == FR_OK)
        LogTextMessage("Global params loaded from '%s'", filename);
    } else if (header.savemode == PRESET_MANAGER_SAVE_MODE_subpatch) {
      err = preset_load_subpatch(&FileObject, &header);
      if (err == FR_OK)
        LogTextMessage("Sub patch params loaded from '%s'", filename);
    }
  }

  if (err != FR_OK) {
    file_error(&FileObject, err, filename);
    return -1;
  }

  err = f_close(&FileObject);
  if (err != FR_OK) {
    file_error(&FileObject, err, filename);
    return -1;
  }

  return 0;
}

/*
 *  This is the intial simple test implentation.
 *  This support will be ditched soon since we have better use for the SRAM.
 */

FRESULT preset_load_subpatch_v1(FIL *FileObject, PresetFileHeader *header) {
  FRESULT err;
  unsigned int bytes_read;
  int n_params;

  DEBUGF("preset_manager::preset_load_subpatch_v1(): header n params = %d, & "
         "NPEXCH = %d",
         n_params, parent->NPEXCH);

  // Yeah... This is messy, but teh V! loadin WILL be ditched ASAP!
  f_lseek(FileObject, 8);
  n_params = header->savemode;

  if (n_params != parent->NPEXCH) {
    DEBUGF("preset_manager::preset_load_subpatch_v1(): n params mismatch");
    return FR_DENIED;
  }

  DEBUGF("preset_manager::preset_load_subpatch_v1(): n params match OK");

  /*
   *  Read the parameters from the file and write them to the patch
   *  PExParameterChange() signaling mask:
   *    0x00000001 -> USB parameter exchange
   *    0x00000002 -> DIN MIDI port
   *    0x00000004 -> Display
   *    0x00000008 -> buttons and dials
   *    0x00000010 -> polling readback enabled (never clear this) (OBSOLETE)
   */
  for (int param_i = 0; param_i < n_params; param_i++) {
    int32_t value;
    err = f_read(FileObject, (uint8_t *)&value, sizeof(int32_t), &bytes_read);
    if (err != FR_OK)
      return err;
    DEBUGF("preset_manager::preset_load_subpatch_v1(): param_i = %d, 0x%08x",
           param_i, value);
    PExParameterChange(&parent->PExch[param_i], value,
                       PRESET_MANAGER_PE_SIGNAL_MASK);
  }

  return FR_OK;
}

FRESULT preset_load_global(FIL *FileObject, PresetFileHeader *header) {
  FRESULT err;
  extern struct KeyValuePair *ObjectKvpRoot;
  extern struct KeyValuePair *ObjectKvps[];
  unsigned int bytes_read;
  int n_params;

  /*
   *  This is the global name/value pair loading.
   *  We may get name clashes with this is there are identically named
   * parameters in different sub patches.
   */
  DEBUGF("preset_manager::preset_load_global(): loading file saved with global "
         "mode");

  n_params = header->n_params;
#ifdef USE_NOOF_PARAMS_TEST
  int n_global_IPVP_params = get_noof_global_IPVP_params();
  if (n_params != n_global_IPVP_params) {
    DEBUGF(
        "preset_manager::preset_load_global(): noof params mismatch %d vs %d",
        n_params, n_global_IPVP_params);
    return FR_DENIED;
  }
#endif

  /*
   *  Read each parameter (hash,value) pair from the file and find a matching
   * ObjectKvps[] entry
   */
  for (int param_i = 0; param_i < n_params; param_i++) {
    uint32_t pair[2];

    err = f_read(FileObject, (uint8_t *)pair, sizeof(pair), &bytes_read);
    if (err != FR_OK)
      return err;

    int global_index = get_global_param_index(pair[0]);
    if (global_index >= 0) {
      DEBUGF("preset_manager::preset_load_global(): PARAM_LOADED OK => name = "
             "'%s', value = 0x%08x",
             ObjectKvps[global_index]->keyname, pair[1]);
      PExParameterChange(ObjectKvps[global_index]->ipvp.PEx, pair[1],
                         PRESET_MANAGER_PE_SIGNAL_MASK);
    } else {
      DEBUGF("preset_manager::preset_load_global(): parameter name mismatch");
      return FR_DENIED;
    }
  }
  return FR_OK;
}

FRESULT preset_load_subpatch(FIL *FileObject, PresetFileHeader *header) {
  FRESULT err;
  extern struct KeyValuePair *ObjectKvpRoot;
  extern struct KeyValuePair *ObjectKvps[];
  unsigned int bytes_read;
  int n_params;
  int n_loaded_params = 0;

  DEBUGF("preset_manager::preset_load_subpatch(): loading file saved with sub "
         "patch mode");

  n_params = header->n_params;
#ifdef USE_NOOF_PARAMS_TEST
  int n_patch_IPVP_params = get_noof_patch_IPVP_params();
  if (n_params != n_patch_IPVP_params) {
    DEBUGF("preset_manager::preset_load_subpatch(): noof params mismatch");
    return FR_DENIED;
  }
#endif

  /*
   *  Read each parameter (hash,value) pair from the file and search for a
   * matching ObjectKvps[] entry to find the right one in case the same param
   * name appears several times in different subpatches. Since some parameters
   * aren't registered globally, we must skip those sub patch params which we
   * can't match with a registered one.
   */
  bool param_found = true;
  for (int patch_i = 0; patch_i < parent->NPEXCH; patch_i++) {
    uint32_t pair[2];

    /*
     *  If the previous parameter in the sub patch was not found in the global
     * registry, that means it was skipped on save, and so the last parameter we
     * read from file is still "the next one" and so we must retry that
     * parameter again.
     */
    if (param_found == true) {
      err = f_read(FileObject, (uint8_t *)pair, sizeof(pair), &bytes_read);
      if (err != FR_OK)
        return err;
    }

    param_found = false;
    for (int global_i = 0; global_i < ObjectKvpRoot->apvp.length; global_i++) {

      // DEBUGF("preset_manager::preset_load_subpatch(): patch_i = %d, global_i
      // = %d", patch_i, global_i );
      // DEBUGF("preset_manager::preset_load_subpatch(): &parent->PExch[patch_i]
      // = 0x%08x, ObjectKvps[global_i]->ipvp.PEx = 0x%08x",
      // &parent->PExch[patch_i], ObjectKvps[global_i]->ipvp.PEx );
      // DEBUGF("preset_manager::preset_load_subpatch(): pair[0] = 0x%08x,
      // ObjectKvps[global_i] hash = 0x%08x, name = %s", pair[0], CalcCRC32(
      // (uint8_t*) ObjectKvps[global_i]->keyname,
      // strlen(ObjectKvps[global_i]->keyname ) ), ObjectKvps[global_i]->keyname
      // );

      if (&parent->PExch[patch_i] == ObjectKvps[global_i]->ipvp.PEx &&
          pair[0] == CalcCRC32((uint8_t *)ObjectKvps[global_i]->keyname,
                               strlen(ObjectKvps[global_i]->keyname))) {
        DEBUGF("preset_manager::preset_load_subpatch(): PARAM LOADED OK => "
               "name = '%s', value = 0x%08x",
               ObjectKvps[global_i]->keyname, pair[1]);
        PExParameterChange(&parent->PExch[patch_i], pair[1],
                           PRESET_MANAGER_PE_SIGNAL_MASK);
        param_found = true;
        n_loaded_params++;
      }
    }
  }
  if (n_loaded_params < parent->NPEXCH) {
    LogTextMessage("%d params less than in current sub patch!",
                   parent->NPEXCH - n_loaded_params);
  }
  return FR_OK;
}

#ifdef USE_PATCHES_FILE
/*
 *  Creates the patches.ppp file where all (sub)patches will register their
 *  parent rootc structure and the number of parameters (NPEXCH is static!).
 *    word 0:   first patch parent->PExch
 *    word 1:   first patch parent->NPEXCH
 *    ..
 *    word N:   last patch parent->PExch
 *    word N+1: last patch parent->NPEXCH
 */
void preset_create_patches_file(void) {
  FRESULT err;
  FIL FileObject;
  unsigned int bytes_written;

  LogTextMessage("preset_manager: creating %s", patches_filename);

  err = f_open(&FileObject, patches_filename, FA_WRITE | FA_CREATE_ALWAYS);
  if (err != FR_OK) {
    report_fatfs_error(err, patches_filename);
  } else {
    int32_t pair[2];
    pair[0] = reinterpret_cast<int32_t>(parent);
    pair[1] = parent->NPEXCH;

    f_lseek(&FileObject, 0);
    err = f_write(&FileObject, (uint8_t *)&pair, sizeof(pair), &bytes_written);
    if (err != FR_OK) {
      report_fatfs_error(err, patches_filename);
    } else {
      LogTextMessage(
          "preset_manager: registered parent patch 0x%08x with %d params",
          parent, parent->NPEXCH);
    }
    f_close(&FileObject);
    if (err != FR_OK) {
      report_fatfs_error(err, patches_filename);
    }
  }
}

/*
 *  Dump the contents of the patches.ppp file for diagnostics
 */
void preset_dump_patches_file(void) {
  FRESULT err;
  FIL FileObject;
  unsigned int bytes_written;

  LogTextMessage("preset_manager: checking %s for registered patches:",
                 patches_filename);

  err = f_open(&FileObject, patches_filename, FA_READ | FA_OPEN_EXISTING);
  if (err != FR_OK) {
    report_fatfs_error(err, patches_filename);
  } else {
    int32_t pair[2];
    rootc *parent_patch;
    int32_t n_patches = f_size(&FileObject) / sizeof(pair);
    unsigned int bytes_read;
    for (int i = 0; i < n_patches; i++) {
      err = f_read(&FileObject, (uint8_t *)&pair, sizeof(pair), &bytes_read);
      if (err != FR_OK) {
        report_fatfs_error(err, patches_filename);
        break;
      }
      parent_patch = reinterpret_cast<rootc *>(pair[0]);
      LogTextMessage("preset_manager: patch %d: PExch = 0x%08x with %d params",
                     i, parent_patch->PExch, pair[1]);
    }
    f_close(&FileObject);
    if (err != FR_OK) {
      report_fatfs_error(err, patches_filename);
    }
  }
}
#endif

start_sequence = 0;
preset_no = 0;
midi_preset_no = 0;
old_inlet_save = 0;
old_param_save = 0;
old_inlet_load = 0;
old_param_load = 0;
load_pulse = 0;
save_pulse = 0;
magic_v2 = "PRS2"; // The file header magic word, version 2
suffix = ".prs";   // The file extension
prefix_copy = "";  // Need the inlet_prefix pointer in the MIDI handler
gain_coeff =
    (1 << 27); // Current volume output, used for fade out/in on save/load
#if attr_volfade < (1 << 27)
fade_rate = 0;
save_load_state = PRESET_MANAGER_SAVE_LOAD_STATE_idle;
#endif
#ifdef USE_PATCHES_FILE
patches_filename = "patches.ppr"; // The "Patch Preset Registry" file
#endif

if (start_sequence < 3) {
  /*
   *  We need to wait one k-rate iteration for signal driven startup actions.
   *  At start_sequence == 0 we do nothing, but wait for signals to propagate in
   * the patch. At start_sequence == 1 we can reliably read inputs, parameters
   * and attributes, and we perform the optional autoloading of a preset.
   */
  LogTextMessage("preset_manager: start_sequence = %d", start_sequence);

  if (start_sequence == 0) {
#ifdef USE_PATCHES_FILE
    preset_create_patches_file();
#endif

#if 0
              // This is only for diagnostics, listing all parameters in all sub patches
              {
                extern struct KeyValuePair *ObjectKvpRoot;
                extern struct KeyValuePair *ObjectKvps[];
                DEBUGF( "preset_manager::krate(): ObjectKvpRoot = 0x%08x, ObjectKvps[%d] = 0x%08x",
                        ObjectKvpRoot, ObjectKvpRoot->apvp.length, ObjectKvps );
                for( int i = 0; i < ObjectKvpRoot->apvp.length; i++ )
                  {
                    switch( ObjectKvps[i]->kvptype )
                      {
                        case KVP_TYPE_IPVP :
                          DEBUGF( "KVP_TYPE_IPVP: .keyname = '%s', .value = 0x%08x",
                            ObjectKvps[i]->keyname != NULL ? ObjectKvps[i]->keyname : "NULL",
                            ObjectKvps[i]->ipvp.PEx->value );
                          break;
                        case KVP_TYPE_IVP :
                          DEBUGF( "KVP_TYPE_IPVP: .keyname = '%s', .value = 0x%08x",
                            ObjectKvps[i]->keyname != NULL ? ObjectKvps[i]->keyname : "NULL",
                            ObjectKvps[i]->ivp.value );
                          break;
                        default :
                          DEBUGF( "KVP_TYPE_ = %d", ObjectKvps[i]->kvptype );
                          break;
                      }
                  }
              }
#endif
  }
#ifdef USE_PATCHES_FILE
  else if (start_sequence == 2) {
    // The master preset_manager can pick up the patches file here.
    // This is just for diagnostics - we'll pick up the file when save/load is
    // triggered the appropriate loader will be called by preset_load().
    preset_dump_patches_file();
  }
#endif
  else if (start_sequence == 1) {
    /*
     *  Check for autoload.
     */
    prefix_copy = inlet_prefix;
    preset_no = param_preset;
    midi_preset_no = preset_no;

    if (attr_autoload >= 0) {
      DEBUGF("preset_manager::krate(): preset autoload");
      if (preset_load(inlet_prefix, attr_autoload) == FR_OK) {
        load_pulse = 1;
        preset_no = attr_autoload;
      }
    }
  }
  start_sequence++;
} else if ((old_inlet_load != inlet_load && inlet_load != 0) ||
           (old_param_load != param_load && param_load == 0)) {
  /*
   *  Load triggered
   */
  DEBUGF("preset_manager::krate(): load_triggered");
  if (old_param_load != param_load && param_load == 0) {
    preset_candidate = param_preset;
  } else {
    preset_candidate = inlet_preset;
  }

#if attr_volfade < (1 << 27)
  // Start fade out
  fade_rate = -attr_volfade;
  save_load_state = PRESET_MANAGER_SAVE_LOAD_STATE_load;
#else
  // Use immediate switching
  codec_clearbuffer();
  if (preset_load(inlet_prefix, preset_candidate) == FR_OK) {
    load_pulse = 1;
    preset_no = preset_candidate;
  }
#endif
} else if ((old_inlet_save != inlet_save && inlet_save != 0) ||
           (old_param_save != param_save && param_save == 0)) {
  /*
   *  Save triggered
   */
  DEBUGF("preset_manager::krate(): save_triggered");
  if (old_param_save != param_save && param_save == 0) {
    preset_candidate = param_preset;
  } else {
    preset_candidate = inlet_preset;
  }

#if attr_volfade < (1 << 27)
  // Start fade out
  fade_rate = -attr_volfade;
  save_load_state = PRESET_MANAGER_SAVE_LOAD_STATE_save;
#else
  // Use immediate switching
  codec_clearbuffer();
  if (preset_save(inlet_prefix, preset_candidate) == FR_OK) {
    // 12.04.2016 17:02 - No save pulse on global saves?
    //                    One more savemode = "GobalNoTrig" for this
    //                    or just skip the pulse?
    //                    or let users do "responsible patching" to avoid
    //                    trigger loops and such.
    save_pulse = 1;
    preset_no = preset_candidate;
  }
#endif
}

#if attr_volfade < (1 << 27)
/*
 *  Waits for the volume to ramp down before performing deferred saving or
 * loading then ramps the volume back up when save or load is done. We save this
 * codespace if immedate presetc switching is used.
 */
if (fade_rate < 0) {
  // Fading out before save/load
  gain_coeff += fade_rate;
  if (gain_coeff <= 0) {
    gain_coeff = 0;
    fade_rate = 0;
    codec_clearbuffer();
    if (save_load_state == PRESET_MANAGER_SAVE_LOAD_STATE_load) {
      if (preset_load(inlet_prefix, preset_candidate) == FR_OK) {
        load_pulse = 1;
        preset_no = preset_candidate;
      }
    } else if (save_load_state == PRESET_MANAGER_SAVE_LOAD_STATE_save) {
      if (preset_save(inlet_prefix, preset_candidate) == FR_OK) {
        save_pulse = 1;
        preset_no = preset_candidate;
      }
    }
    // Start fade in after save/load
    fade_rate = attr_volfade;
    save_load_state = PRESET_MANAGER_SAVE_LOAD_STATE_idle;
  }
} else if (fade_rate > 0) {
  // Fading in after save/load
  gain_coeff += fade_rate;
  if (gain_coeff >= 1 << 27) {
    gain_coeff = 1 << 27;
    fade_rate = 0;
  }
}
#endif

outlet_volume = gain_coeff;
disp_current = preset_no;
outlet_preset = preset_no;
outlet_load = load_pulse;
outlet_save = save_pulse;
old_inlet_load = inlet_load;
old_param_load = param_load;
old_inlet_save = inlet_save;
old_param_save = param_save;
load_pulse = 0;
save_pulse = 0;

/*
 *  The MIDI code is untested!
 *  Include listening for program/bank change messages, CC 0 (MSB) and 32 (LSB)?
 */
if (status == attr_channel + MIDI_PROGRAM_CHANGE) {
  if (attr_pgmchange == 1 && preset_load(prefix_copy, data1) == FR_OK) {
    preset_no = data1;
  }
} else if (status == attr_channel + MIDI_CONTROL_CHANGE) {
  if (data1 == attr_presetcc) {
    midi_preset_no = data2;
  } else if (data1 == attr_loadcc &&
             preset_load(prefix_copy, midi_preset_no) == FR_OK) {
    preset_no = midi_preset_no;
  } else if (data1 == attr_savecc &&
             preset_save(prefix_copy, midi_preset_no) == FR_OK) {
    preset_no = midi_preset_no;
  }
}