//=========================================================================
// FILENAME	: tagutils-misc.c
// DESCRIPTION	: Misc routines for supporting tagutils
//=========================================================================
// Copyright (c) 2008- NETGEAR, Inc. All Rights Reserved.
//=========================================================================

/* This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/**************************************************************************
 * Language
 **************************************************************************/

#define MAX_ICONV_BUF 1024

typedef enum {
  ICONV_OK,
  ICONV_TRYNEXT,
  ICONV_FATAL
} iconv_result;

static iconv_result
do_iconv(const char* to_ces, const char* from_ces,
	 char *inbuf,  size_t inbytesleft,
	 char *outbuf_orig, size_t outbytesleft_orig) {
  size_t rc;
  iconv_result ret = ICONV_OK;

  size_t outbytesleft = outbytesleft_orig - 1;
  char* outbuf = outbuf_orig;

  iconv_t cd  = iconv_open(to_ces, from_ces);
  if (cd == (iconv_t)-1) {
    return ICONV_FATAL;
  }
  rc = iconv(cd, &inbuf, &inbytesleft, &outbuf, &outbytesleft);
  if (rc == (size_t)-1) {
    if (errno == E2BIG) {
      ret = ICONV_FATAL;
    }
    else {
      ret = ICONV_TRYNEXT;
      memset(outbuf_orig, '\0', outbytesleft_orig);
    }
  }
  iconv_close(cd);

  return ret;
}

#define N_LANG_ALT 8
struct {
  char *lang;
  char *cpnames[N_LANG_ALT];
} iconv_map[] = {
  {"JA", {"ISO-8859-1", "CP932", "ISO8859-1", "CP950", "CP936", 0}},
  {"ZH_CN", {"ISO-8859-1", "CP936", "CP950", "CP932", 0}},
  {"ZH_TW", {"ISO-8859-1", "CP950", "CP936", "CP932", 0}},
  {0, {0}}
};
static int lang_index = -1;

static int
_lang2cp(char *lang) {
  int cp;
  if (!lang || lang[0]=='\0')
    return -1;
  for (cp=0; iconv_map[cp].lang; cp++) {
    if (!strcasecmp(iconv_map[cp].lang, lang))
      return cp;
  }
  return -1;
}

static unsigned char*
_get_utf8_text(const id3_ucs4_t* native_text) {
  unsigned char *utf8_text = NULL;
  char *in, *in8, *iconv_buf;
  iconv_result rc;
  int i, n;

  in = (char*) id3_ucs4_latin1duplicate(native_text);
  if (!in) {
    goto out;
  }

  in8 = (char*) id3_ucs4_utf8duplicate(native_text);
  if (!in8) {
    free(in);
    goto out;
  }

  iconv_buf = (char*) calloc(MAX_ICONV_BUF, sizeof(char));
  if (!iconv_buf) {
    free(in); free(in8);
    goto out;
  }

  i = lang_index;
  // (1) try utf8 -> default
  rc = do_iconv(iconv_map[i].cpnames[0], "UTF-8", in8, strlen(in8), iconv_buf, MAX_ICONV_BUF);
  if (rc == ICONV_OK) {
    utf8_text = (unsigned char*) in8;
    free(iconv_buf);
  }
  else if (rc == ICONV_TRYNEXT) {
    // (2) try default -> utf8
    rc = do_iconv("UTF-8", iconv_map[i].cpnames[0], in, strlen(in), iconv_buf, MAX_ICONV_BUF);
    if (rc == ICONV_OK) {
      utf8_text = (unsigned char*) iconv_buf;
    }
    else if (rc == ICONV_TRYNEXT) {
      // (3) try other encodes
      for (n=1; n<N_LANG_ALT && iconv_map[i].cpnames[n]; n++) {
	rc = do_iconv("UTF-8", iconv_map[i].cpnames[n], in, strlen(in), iconv_buf, MAX_ICONV_BUF);
	if (rc == ICONV_OK) {
	  utf8_text = (unsigned char*) iconv_buf;
	  break;
	}
      }
      if (!utf8_text) {
	// cannot iconv
	utf8_text = (unsigned char*) id3_ucs4_utf8duplicate(native_text);
	free(iconv_buf);
      }
    }
    free(in8);
  }
  free(in);

 out:
  if(!utf8_text) {
    utf8_text = (unsigned char*) strdup("UNKNOWN");
  }

  return utf8_text;
}


static void
vc_scan(struct song_metadata *psong, const char *comment, const size_t length)
{
  char strbuf[1024];
  if (length>(sizeof(strbuf)-1)) {
    DPRINTF(E_ERROR, L_SCAN, "Vorbis Comment too long\n");
    return;
  }
  strncpy(strbuf, comment, length);
  strbuf[length] = '\0';

  // ALBUM, ARTIST, PUBLISHER, COPYRIGHT, DISCNUMBER, ISRC, EAN/UPN, LABEL, LABELNO,
  // LICENSE, OPUS, SOURCEMEDIA, TITLE, TRACKNUMBER, VERSION, ENCODED-BY, ENCODING,
  // -- foollowing tags are muliples
  // COMPOSER, ARRANGER, LYRICIST, AUTHOR, CONDUCTOR, PERFORMER, ENSEMBLE, PART
  // PARTNUMBER, GENRE, DATE, LOCATION, COMMENT
  if (!strncasecmp(strbuf, "ALBUM=", 6)) {
    psong->album = strdup(strbuf+6);
  }
  else if (!strncasecmp(strbuf, "ARTIST=", 7)) {
    psong->contributor[ROLE_ARTIST] = strdup(strbuf+7);
  }
  else if (!strncasecmp(strbuf, "ARTISTSORT=", 11)) {
    psong->contributor_sort[ROLE_ARTIST] = strdup(strbuf+11);
  }
  else if (!strncasecmp(strbuf, "TITLE=",6)) {
    psong->title = strdup(strbuf+6);
  }
  else if (!strncasecmp(strbuf, "TRACKNUMBER=", 12)) {
    psong->track = atoi(strbuf+12);
  }
  else if (!strncasecmp(strbuf, "DISCNUMBER=", 11)) {
    psong->disc = atoi(strbuf+11);
  }
  else if (!strncasecmp(strbuf, "GENRE=", 6)) {
    psong->genre = strdup(strbuf+6);
  }
  else if (!strncasecmp(strbuf, "DATE=", 5)) {
    if (length>=(5+10) &&
	isdigit(strbuf[5+0]) && isdigit(strbuf[5+1]) && ispunct(strbuf[5+2]) &&
	isdigit(strbuf[5+3]) && isdigit(strbuf[5+4]) && ispunct(strbuf[5+5]) &&
	isdigit(strbuf[5+6]) && isdigit(strbuf[5+7]) && isdigit(strbuf[5+8]) && isdigit(strbuf[5+9])) {
      // nn-nn-yyyy
      strbuf[5+10] = '\0';
      psong->year = atoi(strbuf+5+6);
    }
    else {
      // year first. year is at most 4 digit.
      strbuf[5+4] = '\0';
      psong->year = atoi(strbuf+5);
    }
  }
  else if (!strncasecmp(strbuf, "COMMENT=", 8)) {
    psong->comment = strdup(strbuf+8);
  }
  else if (!strncasecmp(strbuf, "MUSICBRAINZ_ALBUMID=",20)) {
    psong->musicbrainz_albumid = strdup(strbuf+20);
  }
  else if (!strncasecmp(strbuf, "MUSICBRAINZ_TRACKID=",20)) {
    psong->musicbrainz_trackid = strdup(strbuf+20);
  }
  else if (!strncasecmp(strbuf, "MUSICBRAINZ_TRACKID=",20)) {
    psong->musicbrainz_trackid = strdup(strbuf+20);
  }
  else if (!strncasecmp(strbuf, "MUSICBRAINZ_ARTISTID=",21)) {
    psong->musicbrainz_artistid = strdup(strbuf+21);
  }
  else if (!strncasecmp(strbuf, "MUSICBRAINZ_ALBUMARTISTID=",26)) {
    psong->musicbrainz_albumartistid = strdup(strbuf+26);
  }
}