/* 
   Unix SMB/CIFS mplementation.
   DSDB schema header
   
   Copyright (C) Stefan Metzmacher <metze@samba.org> 2006-2007
   Copyright (C) Andrew Bartlett <abartlet@samba.org> 2006-2008

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.
   
   This program 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 General Public License for more details.
   
   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.
   
*/

#include "includes.h"
#include "dsdb/samdb/samdb.h"

/* a binary array search, where the array is an array of pointers to structures,
   and we want to find a match for 'target' on 'field' in those structures.

   Inputs:
      array:          base pointer to an array of structures
      arrray_size:    number of elements in the array
      field:          the name of the field in the structure we are keying off
      target:         the field value we are looking for
      comparison_fn:  the comparison function
      result:         where the result of the search is put

   if the element is found, then 'result' is set to point to the found array element. If not,
   then 'result' is set to NULL.

   The array is assumed to be sorted by the same comparison_fn as the
   search (with, for example, qsort)
 */
#define BINARY_ARRAY_SEARCH(array, array_size, field, target, comparison_fn, result) do { \
	int32_t _b, _e; \
	(result) = NULL; \
	for (_b = 0, _e = (array_size)-1; _b <= _e; ) {	\
		int32_t _i = (_b+_e)/2; \
		int _r = comparison_fn(target, array[_i]->field); \
		if (_r == 0) { (result) = array[_i]; break; } \
		if (_r < 0) _e = _i - 1; else _b = _i + 1; \
	} } while (0)


static int uint32_cmp(uint32_t c1, uint32_t c2) 
{
	return c1 - c2;
}


const struct dsdb_attribute *dsdb_attribute_by_attributeID_id(const struct dsdb_schema *schema,
							      uint32_t id)
{
	struct dsdb_attribute *c;

	/*
	 * 0xFFFFFFFF is used as value when no mapping table is available,
	 * so don't try to match with it
	 */
	if (id == 0xFFFFFFFF) return NULL;

	BINARY_ARRAY_SEARCH(schema->attributes_by_attributeID_id, 
			    schema->num_attributes, attributeID_id, id, uint32_cmp, c);
	return c;
}

const struct dsdb_attribute *dsdb_attribute_by_attributeID_oid(const struct dsdb_schema *schema,
							       const char *oid)
{
	struct dsdb_attribute *c;

	if (!oid) return NULL;

	BINARY_ARRAY_SEARCH(schema->attributes_by_attributeID_oid, 
			    schema->num_attributes, attributeID_oid, oid, strcasecmp, c);
	return c;
}

const struct dsdb_attribute *dsdb_attribute_by_lDAPDisplayName(const struct dsdb_schema *schema,
							       const char *name)
{
	struct dsdb_attribute *c;

	if (!name) return NULL;

	BINARY_ARRAY_SEARCH(schema->attributes_by_lDAPDisplayName, 
			    schema->num_attributes, lDAPDisplayName, name, strcasecmp, c);
	return c;
}

const struct dsdb_attribute *dsdb_attribute_by_linkID(const struct dsdb_schema *schema,
						      int linkID)
{
	struct dsdb_attribute *c;

	BINARY_ARRAY_SEARCH(schema->attributes_by_linkID, 
			    schema->num_attributes, linkID, linkID, uint32_cmp, c);
	return c;
}

const struct dsdb_class *dsdb_class_by_governsID_id(const struct dsdb_schema *schema,
						    uint32_t id)
{
	struct dsdb_class *c;

	/*
	 * 0xFFFFFFFF is used as value when no mapping table is available,
	 * so don't try to match with it
	 */
	if (id == 0xFFFFFFFF) return NULL;

	BINARY_ARRAY_SEARCH(schema->classes_by_governsID_id, 
			    schema->num_classes, governsID_id, id, uint32_cmp, c);
	return c;
}

const struct dsdb_class *dsdb_class_by_governsID_oid(const struct dsdb_schema *schema,
						     const char *oid)
{
	struct dsdb_class *c;
	if (!oid) return NULL;
	BINARY_ARRAY_SEARCH(schema->classes_by_governsID_oid, 
			    schema->num_classes, governsID_oid, oid, strcasecmp, c);
	return c;
}

const struct dsdb_class *dsdb_class_by_lDAPDisplayName(const struct dsdb_schema *schema,
						       const char *name)
{
	struct dsdb_class *c;
	if (!name) return NULL;
	BINARY_ARRAY_SEARCH(schema->classes_by_lDAPDisplayName, 
			    schema->num_classes, lDAPDisplayName, name, strcasecmp, c);
	return c;
}

const struct dsdb_class *dsdb_class_by_cn(const struct dsdb_schema *schema,
					  const char *cn)
{
	struct dsdb_class *c;
	if (!cn) return NULL;
	BINARY_ARRAY_SEARCH(schema->classes_by_cn, 
			    schema->num_classes, cn, cn, strcasecmp, c);
	return c;
}

const char *dsdb_lDAPDisplayName_by_id(const struct dsdb_schema *schema,
				       uint32_t id)
{
	const struct dsdb_attribute *a;
	const struct dsdb_class *c;

	a = dsdb_attribute_by_attributeID_id(schema, id);
	if (a) {
		return a->lDAPDisplayName;
	}

	c = dsdb_class_by_governsID_id(schema, id);
	if (c) {
		return c->lDAPDisplayName;
	}

	return NULL;
}

/** 
    Return a list of linked attributes, in lDAPDisplayName format.

    This may be used to determine if a modification would require
    backlinks to be updated, for example
*/

WERROR dsdb_linked_attribute_lDAPDisplayName_list(const struct dsdb_schema *schema, TALLOC_CTX *mem_ctx, const char ***attr_list_ret)
{
	const char **attr_list = NULL;
	struct dsdb_attribute *cur;
	int i = 0;
	for (cur = schema->attributes; cur; cur = cur->next) {
		if (cur->linkID == 0) continue;
		
		attr_list = talloc_realloc(mem_ctx, attr_list, const char *, i+2);
		if (!attr_list) {
			return WERR_NOMEM;
		}
		attr_list[i] = cur->lDAPDisplayName;
		i++;
	}
	attr_list[i] = NULL;
	*attr_list_ret = attr_list;
	return WERR_OK;
}

const char **merge_attr_list(TALLOC_CTX *mem_ctx, 
		       const char **attrs, const char * const*new_attrs) 
{
	const char **ret_attrs;
	int i;
	size_t new_len, orig_len = str_list_length(attrs);
	if (!new_attrs) {
		return attrs;
	}

	ret_attrs = talloc_realloc(mem_ctx, 
				   attrs, const char *, orig_len + str_list_length(new_attrs) + 1);
	if (ret_attrs) {
		for (i=0; i < str_list_length(new_attrs); i++) {
			ret_attrs[orig_len + i] = new_attrs[i];
		}
		new_len = orig_len + str_list_length(new_attrs);

		ret_attrs[new_len] = NULL;
	}

	return ret_attrs;
}

/*
  Return a merged list of the attributes of exactly one class (not
  considering subclasses, auxillary classes etc)
*/

const char **dsdb_attribute_list(TALLOC_CTX *mem_ctx, const struct dsdb_class *sclass, enum dsdb_attr_list_query query)
{
	const char **attr_list = NULL;
	switch (query) {
	case DSDB_SCHEMA_ALL_MAY:
		attr_list = merge_attr_list(mem_ctx, attr_list, sclass->mayContain);
		attr_list = merge_attr_list(mem_ctx, attr_list, sclass->systemMayContain);
		break;
		
	case DSDB_SCHEMA_ALL_MUST:
		attr_list = merge_attr_list(mem_ctx, attr_list, sclass->mustContain);
		attr_list = merge_attr_list(mem_ctx, attr_list, sclass->systemMustContain);
		break;
		
	case DSDB_SCHEMA_SYS_MAY:
		attr_list = merge_attr_list(mem_ctx, attr_list, sclass->systemMayContain);
		break;
		
	case DSDB_SCHEMA_SYS_MUST:
		attr_list = merge_attr_list(mem_ctx, attr_list, sclass->systemMustContain);
		break;
		
	case DSDB_SCHEMA_MAY:
		attr_list = merge_attr_list(mem_ctx, attr_list, sclass->mayContain);
		break;
		
	case DSDB_SCHEMA_MUST:
		attr_list = merge_attr_list(mem_ctx, attr_list, sclass->mustContain);
		break;
		
	case DSDB_SCHEMA_ALL:
		attr_list = merge_attr_list(mem_ctx, attr_list, sclass->mayContain);
		attr_list = merge_attr_list(mem_ctx, attr_list, sclass->systemMayContain);
		attr_list = merge_attr_list(mem_ctx, attr_list, sclass->mustContain);
		attr_list = merge_attr_list(mem_ctx, attr_list, sclass->systemMustContain);
		break;
	}
	return attr_list;
}

static const char **dsdb_full_attribute_list_internal(TALLOC_CTX *mem_ctx, 
						const struct dsdb_schema *schema, 
						const char **class_list,
						enum dsdb_attr_list_query query)
{
	int i;
	const struct dsdb_class *sclass;
	
	const char **attr_list = NULL;
	const char **this_class_list;
	const char **recursive_list;

	for (i=0; class_list && class_list[i]; i++) {
		sclass = dsdb_class_by_lDAPDisplayName(schema, class_list[i]);
		
		this_class_list = dsdb_attribute_list(mem_ctx, sclass, query);
		attr_list = merge_attr_list(mem_ctx, attr_list, this_class_list);

		recursive_list = dsdb_full_attribute_list_internal(mem_ctx, schema, 
								   sclass->systemAuxiliaryClass,
								   query);
		
		attr_list = merge_attr_list(mem_ctx, attr_list, recursive_list);
		
		recursive_list = dsdb_full_attribute_list_internal(mem_ctx, schema, 
								   sclass->auxiliaryClass,
								   query);
		
		attr_list = merge_attr_list(mem_ctx, attr_list, recursive_list);
		
	}
	return attr_list;
}

const char **dsdb_full_attribute_list(TALLOC_CTX *mem_ctx, 
				const struct dsdb_schema *schema, 
				const char **class_list,
				enum dsdb_attr_list_query query)
{
	const char **attr_list = dsdb_full_attribute_list_internal(mem_ctx, schema, class_list, query);
	size_t new_len = str_list_length(attr_list);

	/* Remove duplicates */
	if (new_len > 1) {
		int i;
		qsort(attr_list, new_len,
		      sizeof(*attr_list),
		      (comparison_fn_t)strcasecmp);
		
		for (i=1 ; i < new_len; i++) {
			const char **val1 = &attr_list[i-1];
			const char **val2 = &attr_list[i];
			if (ldb_attr_cmp(*val1, *val2) == 0) {
				memmove(val1, val2, (new_len - i) * sizeof( *attr_list)); 
				new_len--;
				i--;
			}
		}
	}
	return attr_list;
}