/* 
   ldb database library

   Copyright (C) Simo Sorce  2004

     ** 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
*/

/*
 *  Name: ldb
 *
 *  Component: ldb modules core
 *
 *  Description: core modules routines
 *
 *  Author: Simo Sorce
 */

#include "includes.h"
#include "ldb/include/ldb.h"
#include "ldb/include/ldb_private.h"
#include "dlinklist.h"
#include <sys/types.h> 
#include <sys/stat.h> 
#include <unistd.h> 

#ifdef HAVE_DLOPEN_DISABLED
#include <dlfcn.h>
#endif

#define LDB_MODULE_PREFIX	"modules"
#define LDB_MODULE_PREFIX_LEN	7
#define LDB_MODULE_SEP		':'

int ldb_load_modules(struct ldb_context *ldb, const char *options[])
{
	struct ldb_module *current;
	char **modules;
	int mnum, i;

	/* find out which modules we are requested to activate */
	modules = NULL;
	mnum = 0;

	if (options) {
		char *q, *p;

		for (i = 0; options[i] != NULL; i++) {
			if (strncmp(options[i], LDB_MODULE_PREFIX, 
				    LDB_MODULE_PREFIX_LEN) == 0) {
				p = q = talloc_strdup(ldb, &options[i][LDB_MODULE_PREFIX_LEN]);
				if (*q != ':') {
					talloc_free(q);
					return -1;
				}
				do {
					*p = '\0';
					q = p + 1;
					mnum++;
					modules = talloc_realloc(ldb, modules, char *, mnum);
					if (!modules) {
						ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_load_modules()\n");
						return -1;
					}
					modules[mnum - 1] = q;
				} while ((p = strchr(q, LDB_MODULE_SEP)));
			}
		}
	}

	if (!modules && strcmp("ldap", ldb->modules->ops->name)) { 
		/* no modules in the options, look for @MODULES in the
		   db (not for ldap) */
		int ret;
		const char * const attrs[] = { "@LIST" , NULL};
		struct ldb_message **msg = NULL;
		char *modstr, *c, *p; 

		ret = ldb_search(ldb, "", LDB_SCOPE_BASE, "dn=@MODULES", attrs, &msg);
		if (ret == 0) {
			ldb_debug(ldb, LDB_DEBUG_TRACE, "no modules required by the db\n");
		} else {
			if (ret < 0) {
				ldb_debug(ldb, LDB_DEBUG_FATAL, "ldb error (%s) occurred searching for modules, bailing out\n", ldb_errstring(ldb));
				return -1;
			}
			if (ret > 1) {
				ldb_debug(ldb, LDB_DEBUG_FATAL, "Too many records found, bailing out\n");
				return -1;
			}

/*
			for (j = 0; j < msg[0]->num_elements; j++) {
				for (k = 0; k < msg[0]->elements[j].num_values; k++) {
					pn++;
					modules = talloc_realloc(ldb, modules, char *, pn);
					if (!modules) {
						ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in register_modules()\n");
						return -1;
					}
					modules[pn - 1] = talloc_strndup(modules, msg[0]->elements[j].values[k].data, msg[0]->elements[j].values[k].length);
					if (!modules[pn - 1]) {
						ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in register_modules()\n");
						return -1;
					}
				}
			}
*/
			modstr = msg[0]->elements[0].values[0].data;
			for (c = modstr, mnum = 0; c != NULL; mnum++) {
				c = strchr(c, ',');
				if (c != NULL) {
					c++;
					if (*c == '\0') { /* avoid failing if the modules string lasts with ',' */
						break;
					}
				}
			}
			

			modules = talloc_array(ldb, char *, mnum);
			if ( ! modules ) {
				ldb_debug(ldb, LDB_DEBUG_FATAL, "Out of Memory in ldb_load_modules()\n");
				return -1;
			}

			for (p = c = modstr, i = 0; mnum > i; i++) {
				c = strchr(p, ',');
				if (c) {
					*c = '\0';
				}
				/* modules are seeked in inverse order. Lets place them as an admin would think the right order is */
				modules[mnum - i - 1] = talloc_strdup(modules, p);
				p = c + 1;
			}
		}
		talloc_free(msg);
	}

	if (modules) {
		for (i = 0; i < mnum; i++) {
#ifdef HAVE_DLOPEN_DISABLED
			void *handle;
			ldb_module_init_function init;
			struct stat st;
			char *filename;
			const char *errstr;
#endif

			if (strcmp(modules[i], "schema") == 0) {
				current = schema_module_init(ldb, options);
				if (!current) {
					ldb_debug(ldb, LDB_DEBUG_FATAL, "function 'init_module' in %s fails\n", modules[i]);
					return -1;
				}
				DLIST_ADD(ldb->modules, current);
				continue;
			}

			if (strcmp(modules[i], "timestamps") == 0) {
				current = timestamps_module_init(ldb, options);
				if (!current) {
					ldb_debug(ldb, LDB_DEBUG_FATAL, "function 'init_module' in %s fails\n", modules[i]);
					return -1;
				}
				DLIST_ADD(ldb->modules, current);
				continue;
			}

			if (strcmp(modules[i], "samldb") == 0) {
				current = samldb_module_init(ldb, options);
				if (!current) {
					ldb_debug(ldb, LDB_DEBUG_FATAL, "function 'init_module' in %s fails\n", modules[i]);
					return -1;
				}
				DLIST_ADD(ldb->modules, current);
				continue;
			}

#ifdef HAVE_DLOPEN_DISABLED
			filename = talloc_asprintf(ldb, "%s.so", modules[i]);
			if (!filename) {
				ldb_debug(ldb, LDB_DEBUG_FATAL, "Talloc failed!\n");
				return -1;
			}

			if (stat(filename, &st) < 0) {
				ldb_debug(ldb, LDB_DEBUG_FATAL, "Required module [%s] not found, bailing out!\n", modules[i]);
				return -1;
			}

			handle = dlopen(filename, RTLD_LAZY);

			if (!handle) {
				ldb_debug(ldb, LDB_DEBUG_FATAL, "Error loading module %s [%s]\n", modules[i], dlerror());
				return -1;
			}

			init = (ldb_module_init_function)dlsym(handle, "init_module");

			errstr = dlerror();
			if (errstr) {
				ldb_debug(ldb, LDB_DEBUG_FATAL, "Error trying to resolve symbol 'init_module' in %s [%s]\n", modules[i], errstr);
				return -1;
			}

			current = init(ldb, options);
			if (!current) {
				ldb_debug(ldb, LDB_DEBUG_FATAL, "function 'init_module' in %s fails\n", modules[i]);
				return -1;
			}
			DLIST_ADD(ldb->modules, current);
#else
			ldb_debug(ldb, LDB_DEBUG_FATAL, "Required module [%s] not found, bailing out!\n", modules[i]);
			return -1;
#endif
		}
	}

	return 0; 
}

/*
   helper functions to call the next module in chain
*/

int ldb_next_search(struct ldb_module *module, 
	       const char *base,
	       enum ldb_scope scope,
	       const char *expression,
	       const char * const *attrs, struct ldb_message ***res)
{
	if (!module->next) {
		return -1;
	}
	return module->next->ops->search(module->next, base, scope, expression, attrs, res);
}

int ldb_next_search_free(struct ldb_module *module, struct ldb_message **msg)
{
	if (!module->next) {
		return -1;
	}
	return module->next->ops->search_free(module->next, msg);
}

int ldb_next_add_record(struct ldb_module *module, const struct ldb_message *message)
{
	if (!module->next) {
		return -1;
	}
	return module->next->ops->add_record(module->next, message);
}

int ldb_next_modify_record(struct ldb_module *module, const struct ldb_message *message)
{
	if (!module->next) {
		return -1;
	}
	return module->next->ops->modify_record(module->next, message);
}

int ldb_next_delete_record(struct ldb_module *module, const char *dn)
{
	if (!module->next) {
		return -1;
	}
	return module->next->ops->delete_record(module->next, dn);
}

int ldb_next_rename_record(struct ldb_module *module, const char *olddn, const char *newdn)
{
	if (!module->next) {
		return -1;
	}
	return module->next->ops->rename_record(module->next, olddn, newdn);
}

int ldb_next_named_lock(struct ldb_module *module, const char *lockname)
{
	if (!module->next) {
		return -1;
	}
	return module->next->ops->named_lock(module->next, lockname);
}

int ldb_next_named_unlock(struct ldb_module *module, const char *lockname)
{
	if (!module->next) {
		return -1;
	}
	return module->next->ops->named_unlock(module->next, lockname);
}

const char *ldb_next_errstring(struct ldb_module *module)
{
	if (!module->next) {
		return NULL;
	}
	return module->next->ops->errstring(module->next);
}