#include <stdio.h>
#include <unistd.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <string.h>
#include <stdlib.h>

inline char *one_argument(char *argument, char *arg_first)
{
  while (*argument <= ' ' && *argument)
    argument++;
  if (*argument == '\'' || *argument == '\"')
  {
    char cEnd = *argument++;
    while (*argument && *argument != cEnd)
      *arg_first++ = *argument++;
    argument++;
  }
  else
    while (*argument > ' ')
      *arg_first++ = *argument++;
  *arg_first = '\0';
  while (*argument <= ' ' && *argument)
    argument++;
  return argument;
}

inline int is_exact_name(char *str, char *namelist)
{
  char name[1024];
  for (;;)
  {
    namelist = one_argument(namelist, name);
    if (!name[0])
      return 0;
    if (!strcasecmp(str,name))
      return 1;
  }
}

char *search_help(int running_level, char *fileName, char *keyword)
{
  static char ret[8192];
  char *cp = ret;
  int i;
  char level[1024], keywords[1024];
  struct stat buf;
  char *file;
  FILE *fp = fopen(fileName, "r");
  if (fp)
  {
    fstat(fileno(fp), &buf);
    file = mmap(NULL, buf.st_size, PROT_READ, MAP_SHARED, fileno(fp), 0);
    if (!file)
      return "mmap failed";
  }
  else return "null fp";
  file = strstr(file, "#HELPS");
  if (!file)
  {
    munmap(file, buf.st_size);
    fclose(fp);
    return "#helps not found";
  }
  file += 6;
  while (1)
  {
    i = 0;
    while (*file <= ' ') file++;
    while (*file > ' ')
      level[i++] = *file++;
    level[i] = '\0';
    file++;
    if (!strcmp(level, "#$"))
    {
      munmap(file, buf.st_size);
      fclose(fp);
      return "File format error";
    }
    while (*file <= ' ') file++;
    i = 0;
    while (*file != '~')
      keywords[i++] = *file++;
    keywords[i] = '\0';
    if (keywords[0] == '$' && !keywords[1])
    {
      munmap(file, buf.st_size);
      fclose(fp);
      return NULL;
    }
    file++;
    if (atoi(level) <= running_level && is_exact_name(keyword, keywords))
    {
      while (*file != '~')
        *cp++ = *file++;
      munmap(file, buf.st_size);
      fclose(fp);
      return ret;
    }
    else
      while (*file != '~')
        file++;
    file++;
  }
}

char *help_text(char *keyword, int level)
{
  char *ret;
  if ((ret = search_help(level, "/home/divine/Rom24/area/help.are", keyword)))
    return ret;
  if ((ret = search_help(level, "/home/divine/Rom24/area/rom.are", keyword)))
    return ret;
  if ((ret = search_help(level, "/home/divine/Rom24/area/group.are", keyword)))
    return ret;
  return "Help File Not Found.";
}