/*----------------------------------------------------------------------------*/
/* Xymon monitor library.                                                     */
/*                                                                            */
/* This is a library module for Xymon, responsible for loading the hosts.cfg  */
/* file and keeping track of what hosts are known, their aliases and planned  */
/* downtime settings etc.                                                     */
/*                                                                            */
/* Copyright (C) 2004-2011 Henrik Storner <henrik@hswn.dk>                    */
/*                                                                            */
/* This program is released under the GNU General Public License (GPL),       */
/* version 2. See the file "COPYING" for details.                             */
/*                                                                            */
/*----------------------------------------------------------------------------*/

static char rcsid_file[] = "$Id: loadhosts_file.c 8069 2019-07-23 15:29:06Z jccleaver $";

static int get_page_name_title(char *buf, char *key, char **name, char **title)
{
	*name = *title = NULL;

	*name = buf + strlen(key); *name += strspn(*name, " \t\r\n");
	if (strlen(*name) > 0) {
		/* (*name) now points at the start of the name. Find end of name */
		*title = *name;
		*title += strcspn(*title, " \t\r\n");
		/* Null-terminate the name */
		**title = '\0'; (*title)++;

		*title += strspn(*title, " \t\r\n");
		return 0;
	}

	return 1;
}

static int pagematch(pagelist_t *pg, char *name)
{
	char *p = strrchr(pg->pagepath, '/');

	if (p) {
		return (strcmp(p+1, name) == 0);
	}
	else {
		return (strcmp(pg->pagepath, name) == 0);
	}
}


static strbuffer_t *contentbuffer = NULL;

static int prepare_fromfile(char *hostsfn, char *extrainclude)
{
	static void *hostfiles = NULL;
	FILE *hosts;
	strbuffer_t *inbuf;

	/* First check if there were no modifications at all */
	if (hostfiles) {
		if (!stackfmodified(hostfiles)){
			return 1;
		}
		else {
			stackfclist(&hostfiles);
			hostfiles = NULL;
		}
	}

	if (!contentbuffer) contentbuffer = newstrbuffer(0);
	clearstrbuffer(contentbuffer);

	hosts = stackfopen(hostsfn, "r", &hostfiles);
	if (hosts == NULL) return -1;

	inbuf = newstrbuffer(20480);
	while (stackfgets(inbuf, extrainclude)) {
		sanitize_input(inbuf, 0, 0);
		addtostrbuffer(contentbuffer, inbuf);
		addtobuffer(contentbuffer, "\n");
	}

	stackfclose(hosts);
	freestrbuffer(inbuf);

	return 0;
}

static int prepare_fromnet(void)
{
	static char contentmd5[33] = { '\0', };
	sendreturn_t *sres;
	sendresult_t sendstat;
	char *fdata, *fhash;

	sres = newsendreturnbuf(1, NULL);
	sendstat = sendmessage("config hosts.cfg", NULL, XYMON_TIMEOUT, sres);
	if (sendstat != XYMONSEND_OK) {
		freesendreturnbuf(sres);
		errprintf("Cannot load hosts.cfg from xymond, code %d\n", sendstat);
		return -1;
	}

	fdata = getsendreturnstr(sres, 1);
	freesendreturnbuf(sres);
	fhash = md5hash(fdata);
	if (strcmp(contentmd5, fhash) == 0) {
		/* No changes */
		xfree(fdata);
		return 1;
	}

	if (contentbuffer) freestrbuffer(contentbuffer);
	contentbuffer = convertstrbuffer(fdata, 0);
	strncpy(contentmd5, fhash, sizeof(contentmd5));

	return 0;
}


char *hostscfg_content(void)
{
	return strdup(STRBUF(contentbuffer));
}

int load_hostnames(char *hostsfn, char *extrainclude, int fqdn)
{
	/* Return value: 0 for load OK, 1 for "No files changed since last load", -1 for error (file not found) */
	int prepresult;
	int ip1, ip2, ip3, ip4, groupid, pageidx;
	char hostname[4096];
	SBUF_DEFINE(dgname);
	pagelist_t *curtoppage, *curpage, *pgtail;
	void * htree;
	char *cfgdata, *inbol, *ineol, insavchar = '\0';

	load_hostinfo(NULL);

	if (*hostsfn == '!')
		prepresult = prepare_fromfile(hostsfn+1, extrainclude);
	else if (extrainclude)
		prepresult = prepare_fromfile(hostsfn, extrainclude);
	else if ((*hostsfn == '@') || (strcmp(hostsfn, xgetenv("HOSTSCFG")) == 0)) {
		prepresult = prepare_fromnet();
		if (prepresult == -1) {
			errprintf("Failed to load from xymond, reverting to file-load\n");
			prepresult = prepare_fromfile(xgetenv("HOSTSCFG"), extrainclude);
		}
	}
	else
		prepresult = prepare_fromfile(hostsfn, extrainclude);

	/* Did we get the data ? */
	if (prepresult == -1) {
		errprintf("Cannot load host data\n");
		return -1;
	}

	/* Any modifications at all ? */
	if (prepresult == 1) {
		dbgprintf("No files modified, skipping reload of %s\n", hostsfn);
		return 1;
	}

	MEMDEFINE(hostname);
	MEMDEFINE(l);

	configloaded = 1;
	initialize_hostlist();
	curpage = curtoppage = pgtail = pghead;
	pageidx = groupid = 0;
	dgname = NULL;

	htree = xtreeNew(strcasecmp);
	inbol = cfgdata = hostscfg_content();
	while (inbol && *inbol) {
		inbol += strspn(inbol, " \t");
		ineol = strchr(inbol, '\n'); 
		if (ineol) {
			while ((ineol > inbol) && (isspace(*ineol) || (*ineol == '\n'))) ineol--;
			if (*ineol != '\n') ineol++;

			insavchar = *ineol;
			*ineol = '\0';
		}

		/* Strip out initial "v" for vpage/vsubpage/vsubparent -- we don't care about the difference here */
		if ((strncmp(inbol, "vpage", 5) == 0) || (strncmp(inbol, "vsubpage", 8) == 0) || (strncmp(inbol, "vsubparent", 10) == 0)) inbol++;

		if (strncmp(inbol, "page", 4) == 0) {
			pagelist_t *newp;
			char *name, *title;

			pageidx = groupid = 0;
			if (dgname) xfree(dgname); dgname = NULL;
			if (get_page_name_title(inbol, "page", &name, &title) == 0) {
				newp = (pagelist_t *)malloc(sizeof(pagelist_t));
				newp->pagepath = strdup(name);
				newp->pagetitle = (title ? strdup(title) : NULL);
				newp->next = NULL;

				pgtail->next = newp;
				pgtail = newp;

				curpage = curtoppage = newp;
			}
		}
		else if (strncmp(inbol, "subpage", 7) == 0) {
			pagelist_t *newp;
			char *name, *title;

			pageidx = groupid = 0;
			if (dgname) xfree(dgname); dgname = NULL;
			if (get_page_name_title(inbol, "subpage", &name, &title) == 0) {
				unsigned int sz;

				newp = (pagelist_t *)malloc(sizeof(pagelist_t));
				sz = strlen(curtoppage->pagepath) + strlen(name) + 2;
				newp->pagepath = malloc(sz);
				snprintf(newp->pagepath, sz, "%s/%s", curtoppage->pagepath, name);
				sz = strlen(curtoppage->pagetitle) + strlen(title) + 2;
				newp->pagetitle = malloc(sz);
				snprintf(newp->pagetitle, sz, "%s/%s", curtoppage->pagetitle, title);
				newp->next = NULL;

				pgtail->next = newp;
				pgtail = newp;

				curpage = newp;
			}
		}
		else if (strncmp(inbol, "subparent", 9) == 0) {
			pagelist_t *newp, *parent;
			char *pname, *name, *title;

			pageidx = groupid = 0;
			if (dgname) xfree(dgname); dgname = NULL;
			parent = NULL;
			if (get_page_name_title(inbol, "subparent", &pname, &title) == 0) {
				for (parent = pghead; (parent && !pagematch(parent, pname)); parent = parent->next);
			}

			if (parent && (get_page_name_title(title, "", &name, &title) == 0)) {
				unsigned int sz;

				newp = (pagelist_t *)malloc(sizeof(pagelist_t));
				sz = strlen(parent->pagepath) + strlen(name) + 2;
				newp->pagepath = malloc(sz);
				snprintf(newp->pagepath, sz, "%s/%s", parent->pagepath, name);
				sz = strlen(parent->pagetitle) + strlen(title) + 2;
				newp->pagetitle = malloc(sz);
				snprintf(newp->pagetitle, sz, "%s/%s", parent->pagetitle, title);
				newp->next = NULL;

				pgtail->next = newp;
				pgtail = newp;

				curpage = newp;
			}
		}
		else if (strncmp(inbol, "group", 5) == 0) {
			char *tok;

			groupid++;
			if (dgname) xfree(dgname); dgname = NULL;

			tok = strtok(inbol, " \t");
			if ((strcmp(tok, "group-only") == 0) || (strcmp(tok, "group-except") == 0)) {
				tok = strtok(NULL, " \t");
			}
			if (tok) tok = strtok(NULL, "\r\n");

			if (tok) {
				char *inp;

				/* Strip HTML tags from the string */
				SBUF_MALLOC(dgname, strlen(tok) + 1);
				*dgname = '\0';

				inp = tok;
				while (*inp) {
					char *tagstart, *tagend;

					tagstart = strchr(inp, '<');
					if (tagstart) {
						tagend = strchr(tagstart, '>');

						*tagstart = '\0';
						if (*inp) strncat(dgname, inp, (dgname_buflen - strlen(dgname)));
						if (tagend) {
							inp = tagend+1;
						}
						else {
							/* Unmatched '<', keep all of the string */
							*tagstart = '<';
							strncat(dgname, tagstart, (dgname_buflen - strlen(dgname)));
							inp += strlen(inp);
						}
					}
					else {
						strncat(dgname, inp, (dgname_buflen - strlen(dgname)));
						inp += strlen(inp);
					}
				}
			}
		}
		else if (sscanf(inbol, "%d.%d.%d.%d %s", &ip1, &ip2, &ip3, &ip4, hostname) == 5) {
			char *startoftags, *tag, *delim;
			int elemidx, elemsize;
			char groupidstr[15];
			xtreePos_t handle;
			namelist_t *newitem;

			if ( (ip1 < 0) || (ip1 > 255) ||
			     (ip2 < 0) || (ip2 > 255) ||
			     (ip3 < 0) || (ip3 > 255) ||
			     (ip4 < 0) || (ip4 > 255)) {
				errprintf("Invalid IPv4-address for host %s (nibble outside 0-255 range): %d.%d.%d.%d\n",
					  hostname, ip1, ip2, ip3, ip4);
				goto nextline;
			}

			newitem = calloc(1, sizeof(namelist_t));

			/* Hostname beginning with '@' are "no-display" hosts. But we still want them. */
			if (*hostname == '@') memmove(hostname, hostname+1, strlen(hostname));

			if (!fqdn) {
				/* Strip any domain from the hostname */
				char *p = strchr(hostname, '.');
				if (p) *p = '\0';
			}

			snprintf(newitem->ip, sizeof(newitem->ip), "%d.%d.%d.%d", ip1, ip2, ip3, ip4);
			snprintf(groupidstr, sizeof(groupidstr), "%d", groupid);
			newitem->groupid = strdup(groupidstr);
			newitem->dgname = (dgname ? strdup(dgname) : strdup("NONE"));
			newitem->pageindex = pageidx++;

			newitem->hostname = strdup(hostname);
			if (ip1 || ip2 || ip3 || ip4) newitem->preference = 1; else newitem->preference = 0;
			newitem->logname = strdup(newitem->hostname);
			{ char *p = newitem->logname; while ((p = strchr(p, '.')) != NULL) { *p = '_'; } }
			newitem->page = curpage;
			newitem->defaulthost = defaulthost;

			startoftags = strchr(inbol, '#');
			if (startoftags == NULL) startoftags = ""; else startoftags++;
			startoftags += strspn(startoftags, " \t\r\n");
			newitem->allelems = strdup(startoftags);
			elemsize = 5;
			newitem->elems = (char **)malloc((elemsize+1)*sizeof(char *));

			tag = newitem->allelems; elemidx = 0;
			while (tag && *tag) {
				if (elemidx == elemsize) {
					elemsize += 5;
					newitem->elems = (char **)realloc(newitem->elems, (elemsize+1)*sizeof(char *));
				}
				newitem->elems[elemidx] = tag;

				/* Skip until we hit a whitespace or a quote */
				tag += strcspn(tag, " \t\r\n\"");
				if (*tag == '"') {
					delim = tag;

					/* Hit a quote - skip until the next matching quote */
					tag = strchr(tag+1, '"');
					if (tag != NULL) { 
						/* Found end-quote, NULL the item here and move on */
						*tag = '\0'; tag++; 
					}

					/* Now move quoted data one byte down (including the NUL) to kill quotechar */
					memmove(delim, delim+1, strlen(delim));
				}
				else if (*tag) {
					/* Normal end of item, NULL it and move on */
					*tag = '\0'; tag++;
				}
				else {
					/* End of line - no more to do. */
					tag = NULL;
				}

				/* 
				 * If we find a "noconn", drop preference value to 0.
				 * If we find a "prefer", up reference value to 2.
				 */
				if ((newitem->preference == 1) && (strcmp(newitem->elems[elemidx], "noconn") == 0))
					newitem->preference = 0;
				else if (strcmp(newitem->elems[elemidx], "prefer") == 0)
					newitem->preference = 2;

				/* Skip whitespace until start of next tag */
				if (tag) tag += strspn(tag, " \t\r\n");
				elemidx++;
			}

			newitem->elems[elemidx] = NULL;

			/* See if this host is defined before */
			handle = xtreeFind(htree, newitem->hostname);
			if (strcasecmp(newitem->hostname, ".default.") == 0) {
				/* The pseudo DEFAULT host */
				newitem->next = newitem->prev = NULL;
				defaulthost = newitem;
			}
			else if (handle == xtreeEnd(htree)) {
				/* New item, so add to end of list */
				newitem->prev = nametail; newitem->next = NULL;
				if (namehead == NULL) 
					namehead = nametail = newitem;
				else {
					nametail->next = newitem;
					nametail = newitem;
				}
				xtreeAdd(htree, newitem->hostname, newitem);
			}
			else {
				namelist_t *existingrec = (namelist_t *)xtreeData(htree, handle);

 				if (newitem->preference <= existingrec->preference) {
					/* Add after the existing (more preferred) entry */
					newitem->next = existingrec->next;
					/* NB: existingrec may be the end of the list, so existingrec->next can be NULL */
					if (newitem->next) newitem->next->prev = newitem;

					existingrec->next = newitem;
					newitem->prev = existingrec;

					if (newitem->next == NULL) nametail = newitem;
				}
				else {
					/* New item has higher preference, so add before the current item (i.e. after existingrec->prev) */
					if (existingrec->prev == NULL) {
						newitem->next = namehead;
						namehead = newitem;
					}
					else {
						newitem->prev = existingrec->prev;
						newitem->next = existingrec;
						existingrec->prev = newitem;
						newitem->prev->next = newitem;
					}
				}
			}

			newitem->clientname = xmh_find_item(newitem, XMH_CLIENTALIAS);
			if (newitem->clientname == NULL) newitem->clientname = newitem->hostname;
			newitem->downtime = xmh_find_item(newitem, XMH_DOWNTIME);

#ifdef DEBUG
			{
				namelist_t *walk;
				int err = 0;

				for (walk = namehead; (walk && !err); walk = walk->next) {
					// printf("%s	%s	%s\n", walk->hostname, (walk->next ? walk->next->hostname: "<null>"), (walk->prev ? walk->prev->hostname : "<null>"));
					if (walk->next && (walk->next->prev != walk)) 
						{ printf("*** ERROR: next->prev is not self\n"); err = 1; }
					if (!walk->next && (walk != nametail)) 
						{ printf("*** ERROR: No next element, but nametail is different\n"); err = 1; }
					if (!walk->prev && (walk != namehead)) 
						{ printf("*** ERROR: No prev element, but namehead is different\n"); err = 1; }
				}

				if (err)
					printf("Error\n");
			}
#endif

		}


nextline:
		if (ineol) {
			*ineol = insavchar;
			if (*ineol != '\n') ineol = strchr(ineol, '\n');

			inbol = (ineol ? ineol+1 : NULL);
		}
		else
			inbol = NULL;
	}

	xfree(cfgdata);
	if (dgname) xfree(dgname);
	xtreeDestroy(htree);

	MEMUNDEFINE(hostname);
	MEMUNDEFINE(l);

	build_hosttree();

	return 0;
}