/* 
   ldb database library

   Copyright (C) Andrew Tridgell  2005

     ** NOTE! The following LGPL license applies to the ldb
     ** library. This does NOT imply that all of Samba is released
     ** under the LGPL
   
   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; if not, write to the Free Software
   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/
/*
  attribute handlers for well known attribute types, selected by syntax OID
  see rfc2252
*/

#include "includes.h"
#include "ldb/include/ldb.h"
#include "ldb/include/ldb_private.h"
#include <ctype.h>

/*
  default handler that just copies a ldb_val.
*/
int ldb_handler_copy(struct ldb_context *ldb, void *mem_ctx,
		     const struct ldb_val *in, struct ldb_val *out)
{
	*out = ldb_val_dup(mem_ctx, in);
	if (in->length > 0 && out->data == NULL) {
		ldb_oom(ldb);
		return -1;
	}
	return 0;
}

/*
  a case folding copy handler, removing leading and trailing spaces and
  multiple internal spaces
*/
static int ldb_handler_fold(struct ldb_context *ldb, void *mem_ctx,
			    const struct ldb_val *in, struct ldb_val *out)
{
	uint8_t *s1, *s2;
	out->data = talloc_size(mem_ctx, strlen((char *)in->data)+1);
	if (out->data == NULL) {
		ldb_oom(ldb);
		return -1;
	}
	s1 = in->data;
	s2 = out->data;
	while (*s1 == ' ') s1++;
	while (*s1) {
		*s2 = toupper(*s1);
		if (s1[0] == ' ') {
			while (s1[0] == s1[1]) s1++;
		}
		s2++; s1++;
	}
	*s2 = 0;
	out->length = strlen((char *)out->data);
	return 0;
}


/*
  canonicalise a ldap Integer
  rfc2252 specifies it should be in decimal form
*/
static int ldb_canonicalise_Integer(struct ldb_context *ldb, void *mem_ctx,
				    const struct ldb_val *in, struct ldb_val *out)
{
	char *end;
	long long i = strtoll((char *)in->data, &end, 0);
	if (*end != 0) {
		return -1;
	}
	out->data = (uint8_t *)talloc_asprintf(mem_ctx, "%lld", i);
	if (out->data == NULL) {
		return -1;
	}
	out->length = strlen((char *)out->data);
	return 0;
}

/*
  compare two Integers
*/
static int ldb_comparison_Integer(struct ldb_context *ldb, void *mem_ctx,
				  const struct ldb_val *v1, const struct ldb_val *v2)
{
	return strtoll((char *)v1->data, NULL, 0) - strtoll((char *)v2->data, NULL, 0);
}

/*
  compare two binary blobs
*/
int ldb_comparison_binary(struct ldb_context *ldb, void *mem_ctx,
			  const struct ldb_val *v1, const struct ldb_val *v2)
{
	if (v1->length != v2->length) {
		return v1->length - v2->length;
	}
	return memcmp(v1->data, v2->data, v1->length);
}

/*
  compare two case insensitive strings, ignoring multiple whitespace
  and leading and trailing whitespace
  see rfc2252 section 8.1
*/
static int ldb_comparison_fold(struct ldb_context *ldb, void *mem_ctx,
			       const struct ldb_val *v1, const struct ldb_val *v2)
{
	const char *s1=(const char *)v1->data, *s2=(const char *)v2->data;
	while (*s1 == ' ') s1++;
	while (*s2 == ' ') s2++;
	/* TODO: make utf8 safe, possibly with helper function from application */
	while (*s1 && *s2) {
		if (toupper((unsigned char)*s1) != toupper((unsigned char)*s2))
			break;
		if (*s1 == ' ') {
			while (s1[0] == s1[1]) s1++;
			while (s2[0] == s2[1]) s2++;
		}
		s1++; s2++;
	}
	while (*s1 == ' ') s1++;
	while (*s2 == ' ') s2++;
	return (int)(toupper(*s1)) - (int)(toupper(*s2));
}

/*
  canonicalise a attribute in DN format
*/
static int ldb_canonicalise_dn(struct ldb_context *ldb, void *mem_ctx,
			       const struct ldb_val *in, struct ldb_val *out)
{
	struct ldb_dn *dn;
	int ret = -1;

	out->length = 0;
	out->data = NULL;

	dn = ldb_dn_explode_casefold(ldb, (char *)in->data);
	if (dn == NULL) {
		return -1;
	}

	out->data = (uint8_t *)ldb_dn_linearize(mem_ctx, dn);
	if (out->data == NULL) {
		goto done;
	}
	out->length = strlen((char *)out->data);

	ret = 0;

done:
	talloc_free(dn);

	return ret;
}

/*
  compare two dns
*/
static int ldb_comparison_dn(struct ldb_context *ldb, void *mem_ctx,
			     const struct ldb_val *v1, const struct ldb_val *v2)
{
	struct ldb_dn *dn1 = NULL, *dn2 = NULL;
	int ret;

	dn1 = ldb_dn_explode_casefold(mem_ctx, (char *)v1->data);
	if (dn1 == NULL) return -1;

	dn2 = ldb_dn_explode_casefold(mem_ctx, (char *)v2->data);
	if (dn2 == NULL) {
		talloc_free(dn1);
		return -1;
	} 

	ret = ldb_dn_compare(ldb, dn1, dn2);

	talloc_free(dn1);
	talloc_free(dn2);
	return ret;
}

/*
  compare two objectclasses, looking at subclasses
*/
static int ldb_comparison_objectclass(struct ldb_context *ldb, void *mem_ctx,
				      const struct ldb_val *v1, const struct ldb_val *v2)
{
	int ret, i;
	const char **subclasses;
	ret = ldb_comparison_fold(ldb, mem_ctx, v1, v2);
	if (ret == 0) {
		return 0;
	}
	subclasses = ldb_subclass_list(ldb, (char *)v1->data);
	if (subclasses == NULL) {
		return ret;
	}
	for (i=0;subclasses[i];i++) {
		struct ldb_val vs;
		vs.data = discard_const(subclasses[i]);
		vs.length = strlen(subclasses[i]);
		if (ldb_comparison_objectclass(ldb, mem_ctx, &vs, v2) == 0) {
			return 0;
		}
	}
	return ret;
}

/*
  compare two utc time values. 1 second resolution
*/
static int ldb_comparison_utctime(struct ldb_context *ldb, void *mem_ctx,
				  const struct ldb_val *v1, const struct ldb_val *v2)
{
	time_t t1, t2;
	t1 = ldb_string_to_time((char *)v1->data);
	t2 = ldb_string_to_time((char *)v2->data);
	return (int)t2 - (int)t1;
}

/*
  canonicalise a utc time
*/
static int ldb_canonicalise_utctime(struct ldb_context *ldb, void *mem_ctx,
				    const struct ldb_val *in, struct ldb_val *out)
{
	time_t t = ldb_string_to_time((char *)in->data);
	out->data = (uint8_t *)ldb_timestring(mem_ctx, t);
	if (out->data == NULL) {
		return -1;
	}
	out->length = strlen((char *)out->data);
	return 0;
}

/*
  table of standard attribute handlers
*/
static const struct ldb_attrib_handler ldb_standard_attribs[] = {
	{ 
		.attr            = LDB_SYNTAX_INTEGER,
		.flags           = 0,
		.ldif_read_fn    = ldb_handler_copy,
		.ldif_write_fn   = ldb_handler_copy,
		.canonicalise_fn = ldb_canonicalise_Integer,
		.comparison_fn   = ldb_comparison_Integer
	},
	{ 
		.attr            = LDB_SYNTAX_OCTET_STRING,
		.flags           = 0,
		.ldif_read_fn    = ldb_handler_copy,
		.ldif_write_fn   = ldb_handler_copy,
		.canonicalise_fn = ldb_handler_copy,
		.comparison_fn   = ldb_comparison_binary
	},
	{ 
		.attr            = LDB_SYNTAX_DIRECTORY_STRING,
		.flags           = 0,
		.ldif_read_fn    = ldb_handler_copy,
		.ldif_write_fn   = ldb_handler_copy,
		.canonicalise_fn = ldb_handler_fold,
		.comparison_fn   = ldb_comparison_fold
	},
	{ 
		.attr            = LDB_SYNTAX_DN,
		.flags           = 0,
		.ldif_read_fn    = ldb_handler_copy,
		.ldif_write_fn   = ldb_handler_copy,
		.canonicalise_fn = ldb_canonicalise_dn,
		.comparison_fn   = ldb_comparison_dn
	},
	{ 
		.attr            = LDB_SYNTAX_OBJECTCLASS,
		.flags           = 0,
		.ldif_read_fn    = ldb_handler_copy,
		.ldif_write_fn   = ldb_handler_copy,
		.canonicalise_fn = ldb_handler_fold,
		.comparison_fn   = ldb_comparison_objectclass
	},
	{ 
		.attr            = LDB_SYNTAX_UTC_TIME,
		.flags           = 0,
		.ldif_read_fn    = ldb_handler_copy,
		.ldif_write_fn   = ldb_handler_copy,
		.canonicalise_fn = ldb_canonicalise_utctime,
		.comparison_fn   = ldb_comparison_utctime
	}
};


/*
  return the attribute handlers for a given syntax name
*/
const struct ldb_attrib_handler *ldb_attrib_handler_syntax(struct ldb_context *ldb,
							   const char *syntax)
{
	int i;
	unsigned num_handlers = sizeof(ldb_standard_attribs)/sizeof(ldb_standard_attribs[0]);
	/* TODO: should be replaced with a binary search */
	for (i=0;i<num_handlers;i++) {
		if (strcmp(ldb_standard_attribs[i].attr, syntax) == 0) {
			return &ldb_standard_attribs[i];
		}
	}
	return NULL;
}