/*
 * tvchannels.c: Translate channel-names from to tuning frequency
 *
 * $Id: tvchannels.c,v 1.2 1997/03/17 00:52:26 mb Exp mb $
 *
 * Copyright (c) 1997 Martin Buck  <martin-2.buck@student.uni-ulm.de>
 * Read COPYING for more information
 *
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <ctype.h>
#include "safe_malloc.h"
#include "misc.h"
#include "tvchannels.h"


typedef struct tvchannel_s {
  char *name;
  int freq;
  struct tvchannel_s *next;
} tvchannel_t;


#define STR_MAXLEN 100
#define FNAME VTX_LIBDIR "/tv-channels"


static int tvsys_count = -1;
static char **tvsys_names;
static tvchannel_t **tvsys_channels;


static void
tvch_init(void) {
  FILE *file;
  char line[256], tmpstr[STR_MAXLEN + 1], sep[2];
  int lcount = 0, tvsys_found = 0, newentry = 0;
  
  tvsys_count = 0;
  if (!(file = fopen(FNAME, "r"))) {
    fprintf(stderr, "%s: Warning: %s\n", FNAME, strerror(errno));
    return;
  }
  
  while (1) {
    if (!fgets(line, sizeof(line), file)) {
      if (feof(file))
        break;
      tvsys_count = 0;
      fprintf(stderr, "%s: Warning: %s\n", FNAME, strerror(errno));
      fclose(file);
      return;
    }
    lcount++;
    
    if (line[0] == '#') {
      continue;
    } else if (sscanf(line, " %1c ", tmpstr) <= 0) {
      tvsys_found = 0;
      continue;
    } else if (tvsys_found != 2) {
      if (sscanf(line, " system  %" STRINGIFY(STR_MAXLEN) "[^\n\r] ", tmpstr) == 1) {
        int entry;
        
        newentry = tvsys_count;
        for (entry = 0; entry < tvsys_count; entry++) {
          if (!strcmp(tmpstr, tvsys_names[entry])) {
            newentry = entry;
            break;
          }
        }
        if (newentry == tvsys_count) {
          tvsys_names = srealloc(tvsys_names, (++tvsys_count) * sizeof(*tvsys_names));
          tvsys_channels = srealloc(tvsys_channels, tvsys_count * sizeof(*tvsys_channels));
          tvsys_names[newentry] = sstrdup(tmpstr);
          tvsys_channels[newentry] = NULL;
        }
        tvsys_found = 2;
      } else {
        if (tvsys_found != 1) {
          fprintf(stderr, "%s:%d: Warning: Missing system-name, succeeding entries ignored.\n",
              FNAME, lcount);
          tvsys_found = 1;
        }
      }
    } else {
      int freq;
      
      if (sscanf(line, " %" STRINGIFY(STR_MAXLEN) "[^\1- =] %1[=] %d ", tmpstr, sep, &freq) >= 2) {
        if (freq >= 0) {
          tvchannel_t **chan = &tvsys_channels[newentry];
          
          while (*chan) {
            if (!strcmp(tmpstr, (*chan)->name)) {
              (*chan)->freq = freq;
              goto chan_done;
            }
            chan = &((*chan)->next);
          }
          *chan = smalloc(sizeof(**chan));
          (*chan)->name = sstrdup(tmpstr);
          (*chan)->freq = freq;
          (*chan)->next = NULL;
chan_done:
	  ;
        } else {
          fprintf(stderr, "%s:%d: Warning: Frequency out of range, line ignored:\n%s\n",
              FNAME, lcount, line);
        }
      } else {
        fprintf(stderr, "%s:%d: Warning: Syntax error, line ignored:\n%s\n", FNAME, lcount, line);
      }
    }
  }
  fclose(file);
}


static int
match_system(const char *system) {
  int entry, pos;

  for (entry = 0; entry < tvsys_count; entry++) {
    if (!strcmp(system, tvsys_names[entry])) {
      return entry;
    }
  }
  for (entry = 0; entry < tvsys_count; entry++) {
    if (!strcasecmp(system, tvsys_names[entry])) {
      return entry;
    }
  }
  /* Why is strncasecmp missing from ANSI C? */
  for (entry = 0; entry < tvsys_count; entry++) {
    pos = 0;
    while (tvsys_names[entry][pos]) {
      if (!system[pos]) {
        return entry;
      }
      if (tolower(system[pos]) != tolower(tvsys_names[entry][pos])) {
        break;
      }
      pos++;
    }
  }
  return -1;
}


int
tvch_get_systems(char const * const **sys_names) {
  if (tvsys_count < 0) {
    tvch_init();
  }
  *sys_names = (char const * const *)tvsys_names;
  return tvsys_count;
}


int
tvch_get_channels(const char *system, char const * const **ch_names) {
  int entry, count;
  static const char **ch_ptrs;
  tvchannel_t *chan;
  
  if (tvsys_count < 0) {
    tvch_init();
  }
  if ((entry = match_system(system)) < 0) {
    return -1;
  }
  chan = tvsys_channels[entry];
  count = 0;
  while (chan) {
    count++;
    chan = chan->next;
  }
  free(ch_ptrs);
  ch_ptrs = smalloc(count * sizeof(const char *));
  chan = tvsys_channels[entry];
  count = 0;
  while (chan) {
    ch_ptrs[count] = chan->name;
    count++;
    chan = chan->next;
  }
  *ch_names = (char const * const *)ch_ptrs;
  return count;
}


int
tvch_chan2freq(const char *system, const char *chname, const char **real_sys_name,
    const char **real_chan_name) {
  int entry;
  tvchannel_t *chan;
  
  if (tvsys_count < 0) {
    tvch_init();
  }
  if (!tvsys_count)
    return -1;
  if (!system) {
    entry = 0;
  } else {
    if ((entry = match_system(system)) < 0) {
      return -1;
    }
  }
  if (real_sys_name) {
    *real_sys_name = tvsys_names[entry];
  }
  if (!chname)
    return entry;
  chan = tvsys_channels[entry];
  while (chan) {
    if (!strcmp(chname, chan->name)) {
      if (real_chan_name) {
        *real_chan_name = chan->name;
      }
      return chan->freq;
    }
    chan = chan->next;
  }
  chan = tvsys_channels[entry];
  while (chan) {
    if (!strcasecmp(chname, chan->name)) {
      if (real_chan_name) {
        *real_chan_name = chan->name;
      }
      return chan->freq;
    }
    chan = chan->next;
  }
  return -1;
}