/* 
   Unix SMB/CIFS implementation.
   Database interface wrapper
   Copyright (C) Jim McDonough <jmcd@us.ibm.com> 2006

   Major code contributions from Aleksey Fedoseev (fedoseev@ru.ibm.com)
   
   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 "dbwrap/dbwrap.h"
#include "dbwrap/dbwrap_private.h"
#include "util_tdb.h"

/*
 * Fall back using fetch_locked if no genuine fetch operation is provided
 */

int dbwrap_fallback_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
			  TDB_DATA key, TDB_DATA *data)
{
	struct db_record *rec;

	if (!(rec = db->fetch_locked(db, mem_ctx, key))) {
		return -1;
	}

	data->dsize = rec->value.dsize;
	data->dptr = talloc_move(mem_ctx, &rec->value.dptr);
	TALLOC_FREE(rec);
	return 0;
}

/*
 * Fall back using fetch if no genuine exists operation is provided
 */

static int dbwrap_fallback_exists(struct db_context *db, TDB_DATA key)
{
	int res = dbwrap_parse_record(db, key, NULL, NULL);
	return  ( res == -1) ? 0 : 1;
}

/*
 * Fall back using fetch if no genuine parse operation is provided
 */

int dbwrap_fallback_parse_record(struct db_context *db, TDB_DATA key,
				 int (*parser)(TDB_DATA key,
					       TDB_DATA data,
					       void *private_data),
				 void *private_data)
{
	TDB_DATA data;
	int res;

	res = db->fetch(db, talloc_tos(), key, &data);
	if (res != 0) {
		return -1;
	}

	res = parser(key, data, private_data);
	TALLOC_FREE(data.dptr);
	return res;
}


static int delete_record(struct db_record *rec, void *data)
{
	NTSTATUS status = rec->delete_rec(rec);
	return NT_STATUS_IS_OK(status) ? 0 : -1;
}

/*
 * Fallback wipe ipmlementation using traverse and delete if no genuine
 * wipe operation is provided
 */
int dbwrap_fallback_wipe(struct db_context *db)
{
	NTSTATUS status = dbwrap_trans_traverse(db, &delete_record, NULL);
	return NT_STATUS_IS_OK(status) ? 0 : -1;
}


/*
 * Wrapper functions for the backend methods
 */

TDB_DATA dbwrap_record_get_key(const struct db_record *rec)
{
	return rec->key;
}

TDB_DATA dbwrap_record_get_value(const struct db_record *rec)
{
	return rec->value;
}

void *dbwrap_record_get_private_data(const struct db_record *rec)
{
	return rec->private_data;
}

NTSTATUS dbwrap_record_store(struct db_record *rec, TDB_DATA data, int flags)
{
	return rec->store(rec, data, flags);
}

NTSTATUS dbwrap_record_delete(struct db_record *rec)
{
	return rec->delete_rec(rec);
}

struct db_record *dbwrap_fetch_locked(struct db_context *db,
				      TALLOC_CTX *mem_ctx,
				      TDB_DATA key)
{
	return db->fetch_locked(db, mem_ctx, key);
}

NTSTATUS dbwrap_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
		      TDB_DATA key, TDB_DATA *value)
{
	if (value == NULL) {
		return NT_STATUS_INVALID_PARAMETER;
	}

	if (db->fetch(db, mem_ctx, key, value) != 0) {
		return NT_STATUS_NOT_FOUND;
	}

	return NT_STATUS_OK;
}

bool dbwrap_exists(struct db_context *db, TDB_DATA key)
{
	int result;
	if (db->exists != NULL) {
		result = db->exists(db, key);
	} else {
		result = dbwrap_fallback_exists(db,key);
	}
	return (result == 1);
}

NTSTATUS dbwrap_store(struct db_context *db, TDB_DATA key,
		      TDB_DATA data, int flags)
{
	struct db_record *rec;
	NTSTATUS status;

	rec = db->fetch_locked(db, talloc_tos(), key);
	if (rec == NULL) {
		return NT_STATUS_NO_MEMORY;
	}

	status = rec->store(rec, data, flags);
	TALLOC_FREE(rec);
	return status;
}

NTSTATUS dbwrap_delete(struct db_context *db, TDB_DATA key)
{
	struct db_record *rec;
	NTSTATUS status;

	rec = db->fetch_locked(db, talloc_tos(), key);
	if (rec == NULL) {
		return NT_STATUS_NO_MEMORY;
	}
	status = rec->delete_rec(rec);
	TALLOC_FREE(rec);
	return status;
}

NTSTATUS dbwrap_traverse(struct db_context *db,
			 int (*f)(struct db_record*, void*),
			 void *private_data,
			 int *count)
{
	int ret = db->traverse(db, f, private_data);

	if (ret < 0) {
		return NT_STATUS_INTERNAL_DB_CORRUPTION;
	}

	if (count != NULL) {
		*count = ret;
	}

	return NT_STATUS_OK;
}

NTSTATUS dbwrap_traverse_read(struct db_context *db,
			      int (*f)(struct db_record*, void*),
			      void *private_data,
			      int *count)
{
	int ret = db->traverse_read(db, f, private_data);

	if (ret < 0) {
		return NT_STATUS_INTERNAL_DB_CORRUPTION;
	}

	if (count != NULL) {
		*count = ret;
	}

	return NT_STATUS_OK;
}

static int dbwrap_null_parser(TDB_DATA key, TDB_DATA val, void* data)
{
	return 0;
}

int dbwrap_parse_record(struct db_context *db, TDB_DATA key,
			int (*parser)(TDB_DATA key, TDB_DATA data,
				      void *private_data),
			void *private_data)
{
	if (parser == NULL) {
		parser = dbwrap_null_parser;
	}

	if (db->parse_record) {
		return db->parse_record(db, key, parser, private_data);
	} else {
		return dbwrap_fallback_parse_record(db, key, parser, private_data);
	}
}

int dbwrap_wipe(struct db_context *db)
{
	return db->wipe(db);
}

int dbwrap_get_seqnum(struct db_context *db)
{
	return db->get_seqnum(db);
}

int dbwrap_get_flags(struct db_context *db)
{
	return db->get_flags(db);
}

int dbwrap_transaction_start(struct db_context *db)
{
	return db->transaction_start(db);
}

int dbwrap_transaction_commit(struct db_context *db)
{
	return db->transaction_commit(db);
}

int dbwrap_transaction_cancel(struct db_context *db)
{
	return db->transaction_cancel(db);
}