/* parse_mon - parse monitorcap entry */

#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <grass/gis.h>
#include <grass/glocale.h>
#include <grass/raster.h>
#include <grass/monitors.h>

static FILE *monitors = NULL;
static struct MON_CAP cap;

static int build_path(char *,char *);
static char *substr(char *,char *);
static int read_line(FILE *,char *,int);

struct MON_CAP *R_parse_monitorcap(int field, char *key)
{
	int  rewound;
	char line[1024];
	char *p;
	char file[500];
	char *gisbase;

	gisbase = G_gisbase();

	rewound = 0;
	if (!(field == MON_NEXT || field == MON_NAME ||
	    field == MON_PATH || field == MON_LINK || field == MON_CLOSE))
		return(NULL);
	if (monitors == NULL)
	{
		sprintf (file, "%s/etc/monitorcap", gisbase) ;
		if ((monitors = fopen(file,"r")) == NULL)
			G_fatal_error("Unable to open %s", file);
	}
	else
	{
		if (field == MON_CLOSE)
		{
			fclose(monitors);
			monitors = NULL;
			return(NULL);
		}
	}
	while (-1)
	{
		if (read_line(monitors,line,sizeof line))
		{
			if (field == MON_NEXT)
				return(NULL);
			rewind(monitors);
			if (read_line(monitors,line,sizeof line) || rewound)
				return(NULL);
			rewound = -1;
		}
		build_path (line, gisbase);
		cap.path = cap.comment = cap.link = cap.tty = cap.where = NULL;
		if ((cap.name = G_malloc(strlen(line)+1)) == NULL)
			return(NULL);
		strcpy(cap.name,line);
		if ((p = substr(":",cap.name)) != NULL)
		{
			*p++ = '\0';
			cap.path = p;
			if ((p = substr(":",p)) != NULL)
			{
				*p++ = '\0';
				cap.comment = p;
				if ((p = substr(":",p)) != NULL)
				{
					*p++ = '\0';
					cap.link = p;
					if ((p = substr(":",p)) != NULL)
					{
						*p++ = '\0';
						cap.tty = p;
						if ((p = substr(":",p)) != NULL)
						{
							*p++ = 0;
							cap.where = p;
							if ((p = substr("\n",p)) != NULL)
								*p = '\0';
						}
					}
				}
			}
		}
		if( cap.path==NULL || cap.link==NULL || cap.where==NULL|| cap.tty == NULL || cap.comment==NULL)
		   G_free(cap.name);
                else
		{
  		   if (field == MON_NEXT || (field == MON_NAME && !strcmp(key,cap.name))
		       || (field == MON_PATH && !strcmp(key, cap.path))
		       || (field == MON_LINK && !strcmp(key,cap.link)))
		   	return(&cap);
		   else
		   	G_free(cap.name);
                }
	}
}

/* read_line - read a line, possibly continued with a "\" into a buffer */

static int read_line(
FILE *file,				/* file from which to read */
char *line,				/* buffer in which to put it */
int size)				/* size of buffer */
{
	int length, full_line, eof, done;
	char c, last_c;

	*line ='\0';
	for (length = full_line = eof = 0; !full_line && !eof; )
	{					/*   one entire line at a time */
		while(1)
		{
			eof = (fgets(line + length,size - length - 1,file) == NULL);
			if (eof)
				break ;
			if (*(line+length) != '#')
				break ;
		}
		length = strlen(line) - 1;
		if (*(line + length) == '\n')
		{
			if (*(line + length - 1) == '\\')
				--length;
			else
				full_line = -1;
		}
		else
		{
			if (length != -1)
			{
				fprintf(stderr,"error:  input line too long\n");
				full_line = -1;
				last_c = c = ' ';
				for (done = 0; !done; )
				{
					if((c = getc(file)) != EOF)
					{
						if (c == '\n' && last_c != '\\')
							done = -1;
						else
							last_c = c;
					}
					else
						eof = done = -1;
				}
			}
		}
	}
	return(eof);
}

/* substr - find substring in a string.  returns pointer to start of */
/* substring or NULL if not found */

static char *substr(char *string,char *buffer)
{
	int start, i, found;
	char c;

	start = i = found = 0;
	while ((c = *(buffer + start + i)) != '\0' && !found)
	{
		if (c == *(string + i))
		{
			if (*(string + ++i) == '\0')
				found = -1;
		}
		else
		{
			start++;
			i = 0;
		}
	}
	if (found)
		return(buffer + start);
	else
		return(NULL);
}

static int build_path(char *line,char *gisbase)
{
	char temp[1024];
	char *t, *l;

	/* second field is monitor program
 * if it doesn't start with / then prepend gisbase
 */

	t = substr (":", line);
	if (t == NULL)
	{
		return 1;
	}
	if (t[1] == '/')
	{
		return 1;	/* aready a full path name */
	}

	/* copy up to first : */
	t = temp;
	l = line;
	while (*l != ':')
		*t++ = *l++;
	*t++ = *l++;

	/* prepend gisbase */
	while (*gisbase)
		*t++ = *gisbase++;
	*t++ = '/' ;

	/* copy rest of line */
	while (*t++ = *l++);

	/* now put it all back into the original line */
	strcpy (line, temp);

	return 0;
}