/* drmr_hydrogen.c
 * LV2 DrMr plugin
 * Copyright 2012 Nick Lanham <nick@afternight.org>
 *
 * Public License v3. source code is available at 
 * <http://github.com/nicklan/drmr>

 * THIS SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

// Utilities for loading up a hydrogen kit

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <sys/types.h>
#include <dirent.h>
#include <errno.h>

#include "drmr.h"
#include "drmr_hydrogen.h"
#include "expat.h"

static char* default_drumkit_locations[] = {
  "/usr/share/hydrogen/data/drumkits/",
  "/usr/local/share/hydrogen/data/drumkits/",
  "~/.hydrogen/data/drumkits/",
  NULL
};

#define MAX_CHAR_DATA 512

struct instrument_info {
  int id;
  char* filename;
  char* name;
  struct instrument_info* next;
  // maybe pan/vol/etc..
};

struct kit_info {
  char* name;
  char* desc;
  // linked list of intruments, null terminated
  struct instrument_info* instruments;
};

struct hp_info {
  char scan_only;
  char in_info;
  char in_instrument_list;
  char in_instrument;
  int  cur_off;
  char cur_buf[MAX_CHAR_DATA];
  struct instrument_info* cur_instrument;
  struct kit_info* kit_info;
};


static void XMLCALL
startElement(void *userData, const char *name, const char **atts)
{
  struct hp_info* info = (struct hp_info*)userData;
  info->cur_off = 0;
  if (info->in_info) {
    if (info->in_instrument_list) {
      if (!strcmp(name,"instrument")) {
	info->in_instrument = 1;
	if (!info->scan_only) {
	  info->cur_instrument = malloc(sizeof(struct instrument_info));
	  memset(info->cur_instrument,0,sizeof(struct instrument_info));
	}
      }
    } else {
      if (!strcmp(name,"instrumentList"))
	info->in_instrument_list = 1;
    }
  } else {
    if (!strcmp(name,"drumkit_info"))
      info->in_info = 1;
  }
}

static void XMLCALL
endElement(void *userData, const char *name)
{
  struct hp_info* info = (struct hp_info*)userData;
  if (info->cur_off == MAX_CHAR_DATA) info->cur_off--;
  info->cur_buf[info->cur_off]='\0';

  if (info->in_info && !info->in_instrument_list && !strcmp(name,"name"))
    info->kit_info->name = strdup(info->cur_buf);
  if (info->scan_only && info->in_info && !info->in_instrument_list && !strcmp(name,"info"))
    info->kit_info->desc = strdup(info->cur_buf);

  if (!info->scan_only && info->in_instrument) {
    if (!strcmp(name,"id"))
      info->cur_instrument->id = atoi(info->cur_buf);
    if (!strcmp(name,"filename"))
      info->cur_instrument->filename = strdup(info->cur_buf);
    if (!strcmp(name,"name"))
      info->cur_instrument->name = strdup(info->cur_buf);
  }
    

  info->cur_off = 0;

  if (!info->scan_only && 
      info->in_instrument && 
      !strcmp(name,"instrument") && 
      info->cur_instrument->filename) {
    struct instrument_info * cur_i = info->kit_info->instruments;
    if (cur_i) {
      while(cur_i->next) cur_i = cur_i->next;
      cur_i->next = info->cur_instrument;
    } else
      info->kit_info->instruments = info->cur_instrument;
    info->cur_instrument = NULL;
    info->in_instrument = 0;
  }
  if (info->in_instrument_list && !strcmp(name,"instrumentList")) info->in_instrument_list = 0;
  if (info->in_info && !strcmp(name,"drumkit_info")) info->in_info = 0;
}

static void XMLCALL
charData(void *userData,
	 const char* data,
	 int len) {
  int i;
  struct hp_info* info = (struct hp_info*)userData;
  if (!info->in_info) return;
  for(i = 0;i<len;i++) {
    if (info->cur_off < MAX_CHAR_DATA) {
      info->cur_buf[info->cur_off] = data[i];
      info->cur_off++;
    }
  }
}

struct kit_list {
  scanned_kit* skit;
  struct kit_list* next;
};

kits* scan_kits() {
  DIR* dp;
  FILE* file;
  XML_Parser parser;
  int done;
  struct hp_info info;
  struct kit_info kit_info;
  struct dirent *ep;
  int cp = 0;
  char* cur_path = default_drumkit_locations[cp++];
  kits* ret = malloc(sizeof(kits));
  struct kit_list* scanned_kits = NULL,*cur_kit;
  char buf[BUFSIZ];

  ret->num_kits = 0;

  while (cur_path) {
    dp = opendir (cur_path);
    if (dp != NULL) {
      while (ep = readdir (dp)) {
	if (ep->d_name[0]=='.') continue;
	if (snprintf(buf,BUFSIZ,"%s/%s/drumkit.xml",cur_path,ep->d_name) >= BUFSIZ) {
	  fprintf(stderr,"Warning: Skipping scan of %s as path name is too long\n",cur_path);
	  continue;
	}
	file = fopen(buf,"r");
	if (!file) continue; // couldn't open file
	parser = XML_ParserCreate(NULL);
	memset(&info,0,sizeof(struct hp_info));
	memset(&kit_info,0,sizeof(struct kit_info));
	info.kit_info = &kit_info;
	info.scan_only = 1;
	XML_SetUserData(parser, &info);
	XML_SetElementHandler(parser, startElement, endElement);  
	XML_SetCharacterDataHandler(parser, charData);
	do {
	  int len = (int)fread(buf, 1, sizeof(buf), file);
	  done = len < sizeof(buf);
	  if (XML_Parse(parser, buf, len, done) == XML_STATUS_ERROR) {
	    fprintf(stderr,
		    "%s at line %lu\n",
		    XML_ErrorString(XML_GetErrorCode(parser)),
		    XML_GetCurrentLineNumber(parser));
	    break;
	  }
	} while (!done);
	XML_ParserFree(parser);
	if (info.kit_info->name) {
	  scanned_kit* kit = malloc(sizeof(scanned_kit));
	  struct kit_list* node = malloc(sizeof(struct kit_list));
	  memset(kit,0,sizeof(scanned_kit));
	  memset(node,0,sizeof(struct kit_list));
	  kit->name = info.kit_info->name;
	  kit->desc = info.kit_info->desc;
	  snprintf(buf,BUFSIZ,"%s/%s/",cur_path,ep->d_name);
	  kit->path = strdup(buf);
	  node->skit = kit;
	  struct kit_list * cur_k = scanned_kits;
	  if (cur_k) {
	    while(cur_k->next) cur_k = cur_k->next;
	    cur_k->next = node;
	  } else
	    scanned_kits = node;
	}
      }
      (void) closedir (dp);
    }
    else
      fprintf(stderr,"Couldn't open %s: %s\n",cur_path,strerror(errno));
    cur_path = default_drumkit_locations[cp++];
  }

  // valid kits are in scanned_kits at this point
  cp = 0;
  struct kit_list * cur_k = scanned_kits;
  while(cur_k) {
    //printf("found kit: %s\nat:%s\n\n",cur_k->skit->name,cur_k->skit->path);
    cur_k = cur_k->next;
    cp++;
  }

  printf("found %i kits\n",cp);
  ret->num_kits = cp;
  ret->kits = malloc(cp*sizeof(scanned_kit));

  cur_k = scanned_kits;
  cp = 0;
  while(cur_k) {
    ret->kits[cp].name = cur_k->skit->name;
    ret->kits[cp].desc = cur_k->skit->desc;
    ret->kits[cp].path = cur_k->skit->path;
    cp++;
    free(cur_k->skit);
    cur_k = cur_k->next;
    // free each node as we go along
    free(scanned_kits);
    scanned_kits = cur_k;
  }

  return ret;
}

void free_samples(drmr_sample* samples, int num_samples) {
  int i;
  for (i=0;i<num_samples;i++)
    if (samples[i].data)
      free(samples[i].data);
  free(samples);
}

int load_hydrogen_kit(DrMr* drmr, char* path) {
  char* fp_buf;
  FILE* file;
  char buf[BUFSIZ];
  XML_Parser parser;
  int done;
  struct hp_info info;
  struct kit_info kit_info;

  snprintf(buf,BUFSIZ,"%s/drumkit.xml",path);
  
  printf("trying to load: %s\n",buf);

  file = fopen(buf,"r");
  if (!file) {
    perror("Unable to open file:");
    return 1;
  }

  parser = XML_ParserCreate(NULL);
  memset(&info,0,sizeof(struct hp_info));
  memset(&kit_info,0,sizeof(struct kit_info));

  info.kit_info = &kit_info;

  XML_SetUserData(parser, &info);
  XML_SetElementHandler(parser, startElement, endElement);  
  XML_SetCharacterDataHandler(parser, charData);

  do {
    int len = (int)fread(buf, 1, sizeof(buf), file);
    done = len < sizeof(buf);
    if (XML_Parse(parser, buf, len, done) == XML_STATUS_ERROR) {
      fprintf(stderr,
              "%s at line %lu\n",
              XML_ErrorString(XML_GetErrorCode(parser)),
              XML_GetCurrentLineNumber(parser));
      return 1;
    }
  } while (!done);
  XML_ParserFree(parser);

  {
    drmr_sample *samples, *old_samples;
    struct instrument_info * cur_i;
    int i = 0, num_inst = 0, old_scount;
    printf("Read kit: %s\n",kit_info.name);
    cur_i = kit_info.instruments;
    while(cur_i) { // first count how many samples we have
      num_inst ++;
      cur_i = cur_i->next;
    }
    printf("Loading %i instruments\n",num_inst);
    samples = malloc(num_inst*sizeof(drmr_sample));
    cur_i = kit_info.instruments;
    while(cur_i) {
      snprintf(buf,BUFSIZ,"%s/%s",path,cur_i->filename);
      if (load_sample(buf,samples+i)) {
	fprintf(stderr,"Could not load sample: %s\n",buf);
	samples[i].offset = 0;
	// set limit to zero, will never try and play
	samples[i].limit = 0; 
	samples[i].data = NULL;
      }
      i++;
      cur_i = cur_i->next;
    }
    old_samples = drmr->samples;
    old_scount = drmr->num_samples;
    if (num_inst > drmr->num_samples) { 
      // we have more, so we can safely swap our sample list in before updating num_samples
      drmr->samples = samples;
      drmr->num_samples = num_inst;
    } else {
      // previous has more, update count first
      drmr->num_samples = num_inst;
      drmr->samples = samples;
    }
    if (old_samples) free_samples(old_samples,old_scount);
  }
  return 0;
  
}