/*
 * Copyright (c) 1999, Boris Popov
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    This product includes software developed by Boris Popov.
 * 4. Neither the name of the author nor the names of any co-contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * $FreeBSD$
 */
#include <sys/types.h>
#include <sys/queue.h>
#include <ctype.h>
#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <pwd.h>
#include <unistd.h>

#include <netncp/ncp_lib.h>
#include <netncp/ncp_rcfile.h>
#include <netncp/ncp_cfg.h>

#define NWFS_CFG_FILE	NCP_PREFIX"/etc/nwfs.conf"

struct rcfile *ncp_rc = NULL;

SLIST_HEAD(rcfile_head, struct rcfile);
static struct rcfile_head pf_head = {NULL};

int rc_merge(char *filename,struct rcfile **rcfile);
static struct rcfile* rc_find(char *filename);
static struct rcsection *rc_findsect(struct rcfile *rcp, char *sectname);
static struct rcsection *rc_addsect(struct rcfile *rcp, char *sectname);
static int rc_sect_free(struct rcsection *rsp);
static struct rckey *rc_sect_findkey(struct rcsection *rsp, char *keyname);
static struct rckey *rc_sect_addkey(struct rcsection *rsp, char *name, char *value);
static void rc_key_free(struct rckey *p);
static void rc_parse(struct rcfile *rcp);


/*
 * open rcfile and load its content, if already open - return previous handle
 */
int
rc_open(char *filename,char *mode,struct rcfile **rcfile) {
	struct rcfile *rcp;
	FILE *f;
	
	rcp = rc_find(filename);
	if( rcp ) {
		*rcfile = rcp;
		return 0;
	}
	f = fopen (filename, mode);
	if (f==NULL)
		return errno;
	rcp = malloc(sizeof(struct rcfile));
	if (rcp==NULL) {
		fclose(f);
		return ENOMEM;
	}
	bzero(rcp, sizeof(struct rcfile));
	rcp->rf_name = strdup (filename);
	rcp->rf_f = f;
	SLIST_INSERT_HEAD(&pf_head, rcp, rf_next);
	rc_parse(rcp);
	*rcfile = rcp;
	return 0;
}

int
rc_merge(char *filename,struct rcfile **rcfile) {
	struct rcfile *rcp = *rcfile;
	FILE *f, *t;
	
	if (rcp == NULL) {
		return rc_open(filename,"r",rcfile);
	}
	f = fopen (filename, "r");
	if (f==NULL)
		return errno;
	t = rcp->rf_f;
	rcp->rf_f = f;
	rc_parse(rcp);
	rcp->rf_f = t;
	fclose(f);
	return 0;
}

int
rc_close(struct rcfile *rcp) {
	struct rcsection *p,*n;

	fclose(rcp->rf_f);
	for(p = SLIST_FIRST(&rcp->rf_sect);p;) {
		n = p;
		p = SLIST_NEXT(p,rs_next);
		rc_sect_free(n);
	}
	free(rcp->rf_name);
	SLIST_REMOVE(&pf_head, rcp, struct rcfile, rf_next);
	free(rcp);
	return 0;
}

static struct rcfile*
rc_find(char *filename) {
	struct rcfile *p;

	SLIST_FOREACH(p, &pf_head, rf_next)
		if (strcmp (filename, p->rf_name)==0)
			return p;
	return 0;
}

static struct rcsection *
rc_findsect(struct rcfile *rcp, char *sectname) {
	struct rcsection *p;

	SLIST_FOREACH(p, &rcp->rf_sect, rs_next)
		if (strcmp(p->rs_name, sectname)==0)
			return p;
	return NULL;
}

static struct rcsection *
rc_addsect(struct rcfile *rcp, char *sectname) {
	struct rcsection *p;

	p = rc_findsect(rcp, sectname);
	if (p) return p;
	p = malloc(sizeof(*p));
	if (!p) return NULL;
	p->rs_name = strdup(sectname);
	SLIST_INIT(&p->rs_keys);
	SLIST_INSERT_HEAD(&rcp->rf_sect, p, rs_next);
	return p;
}

static int
rc_sect_free(struct rcsection *rsp) {
	struct rckey *p,*n;

	for(p = SLIST_FIRST(&rsp->rs_keys);p;) {
		n = p;
		p = SLIST_NEXT(p,rk_next);
		rc_key_free(n);
	}
	free(rsp->rs_name);
	free(rsp);
	return 0;
}

static struct rckey *
rc_sect_findkey(struct rcsection *rsp, char *keyname) {
	struct rckey *p;

	SLIST_FOREACH(p, &rsp->rs_keys, rk_next)
		if (strcmp(p->rk_name, keyname)==0)
			return p;
	return NULL;
}

static struct rckey *
rc_sect_addkey(struct rcsection *rsp, char *name, char *value) {
	struct rckey *p;

	p = rc_sect_findkey(rsp, name);
	if (p) {
		free(p->rk_value);
	} else {
		p = malloc(sizeof(*p));
		if (!p) return NULL;
		SLIST_INSERT_HEAD(&rsp->rs_keys, p, rk_next);
		p->rk_name = strdup(name);
	}
	p->rk_value = value ? strdup(value) : strdup("");
	return p;
}

void
rc_sect_delkey(struct rcsection *rsp, struct rckey *p) {

	SLIST_REMOVE(&rsp->rs_keys,p,struct rckey,rk_next);
	rc_key_free(p);
	return;
}

static void
rc_key_free(struct rckey *p){
	free(p->rk_value);
	free(p->rk_name);
	free(p);
}

enum { stNewLine, stHeader, stSkipToEOL, stGetKey, stGetValue};

static void
rc_parse(struct rcfile *rcp) {
	FILE *f = rcp->rf_f;
	int state = stNewLine, c;
	struct rcsection *rsp = NULL;
	struct rckey *rkp = NULL;
	char buf[2048];
	char *next = buf, *last = &buf[sizeof(buf)-1];

	while ((c = getc (f)) != EOF) {
		if (c == '\r')
			continue;
		if (state == stNewLine) {
			next = buf;
			if (isspace(c))
				continue;	/* skip leading junk */
			if (c == '[') {
				state = stHeader;
				rsp = NULL;
				continue;
			}
			if (c == '#' || c == ';') {
				state = stSkipToEOL;
			} else {		/* something meaningfull */
				state = stGetKey;
			}
		}
		if (state == stSkipToEOL || next == last) {/* ignore long lines */
			if (c == '\n'){
				state = stNewLine;
				next = buf;
			}
			continue;
		}
		if (state == stHeader) {
			if (c == ']') {
				*next = 0;
				next = buf;
				rsp = rc_addsect(rcp, buf);
				state = stSkipToEOL;
			} else
				*next++ = c;
			continue;
		}
		if (state == stGetKey) {
			if (c == ' ' || c == '\t')/* side effect: 'key name='*/
				continue;	  /* become 'keyname=' 	     */
			if (c == '\n') {		/* silently ignore ... */
				state = stNewLine;
				continue;
			}
			if (c != '=') {
				*next++ = c;
				continue;
			}
			*next = 0;
			if (rsp == NULL) {
				fprintf(stderr, "Key '%s' defined before section\n", buf);
				state = stSkipToEOL;
				continue;
			}
			rkp = rc_sect_addkey(rsp, buf, NULL);
			next = buf;
			state = stGetValue;
			continue;
		}
		/* only stGetValue left */
		if (state != stGetValue) {
			fprintf(stderr, "Well, I can't parse file '%s'\n",rcp->rf_name);
			state = stSkipToEOL;
		}
		if (c != '\n') {
			*next++ = c;
			continue;
		}
		*next = 0;
		rkp->rk_value = strdup(buf);
		state = stNewLine;
		rkp = NULL;
	} 	/* while */
	if (c == EOF && state == stGetValue) {
		*next = 0;
		rkp->rk_value = strdup(buf);
	}
	return;
}

int
rc_getstringptr(struct rcfile *rcp,char *section, char *key,char **dest) {
	struct rcsection *rsp;
	struct rckey *rkp;
	
	*dest = NULL;
	rsp = rc_findsect(rcp, section);
	if (!rsp) return ENOENT;
	rkp = rc_sect_findkey(rsp,key);
	if (!rkp) return ENOENT;
	*dest = rkp->rk_value;
	return 0;
}

int
rc_getstring(struct rcfile *rcp,char *section, char *key,int maxlen,char *dest) {
	char *value;
	int error;
	
	error = rc_getstringptr(rcp, section, key, &value);
	if (error) return error;
	if (strlen(value) >= maxlen) {
		fprintf(stderr, "line too long for key '%s' in section '%s', max = %d\n",key, section, maxlen);
		return EINVAL;
	}
	strcpy(dest,value);
	return 0;
}

int
rc_getint(struct rcfile *rcp,char *section, char *key,int *value) {
	struct rcsection *rsp;
	struct rckey *rkp;
	
	rsp = rc_findsect(rcp, section);
	if (!rsp) return ENOENT;
	rkp = rc_sect_findkey(rsp,key);
	if (!rkp) return ENOENT;
	errno = 0;
	*value = strtol(rkp->rk_value,NULL,0);
	if (errno) {
		fprintf(stderr, "invalid int value '%s' for key '%s' in section '%s'\n",rkp->rk_value,key,section);
		return errno;
	}
	return 0;
}

/*
 * 1,yes,true
 * 0,no,false
 */
int
rc_getbool(struct rcfile *rcp,char *section, char *key,int *value) {
	struct rcsection *rsp;
	struct rckey *rkp;
	char *p;
	
	rsp = rc_findsect(rcp, section);
	if (!rsp) return ENOENT;
	rkp = rc_sect_findkey(rsp,key);
	if (!rkp) return ENOENT;
	p = rkp->rk_value;
	while (*p && isspace(*p)) p++;
	if (*p == '0' || strcasecmp(p,"no") == 0 || strcasecmp(p,"false") == 0) {
		*value = 0;
		return 0;
	}
	if (*p == '1' || strcasecmp(p,"yes") == 0 || strcasecmp(p,"true") == 0) {
		*value = 1;
		return 0;
	}
	fprintf(stderr, "invalid boolean value '%s' for key '%s' in section '%s' \n",p, key, section);
	return EINVAL;
}

/*
 * first read ~/.nwfsrc, next try to merge NWFS_CFG_FILE
 */
int
ncp_open_rcfile(void) {
	char *home, *fn;
	int error;

	home = getenv("HOME");
	if (home) {
		fn = malloc(strlen(home) + 20);
		sprintf(fn, "%s/.nwfsrc", home);
		error = rc_open(fn,"r",&ncp_rc);
		free (fn);
	}
	error = rc_merge(NWFS_CFG_FILE, &ncp_rc);
	if( ncp_rc == NULL ) {
		printf("Warning: no cfg files found.\n");
		return 1;
	}
	return 0;
}