/*
 *  Unix SMB/CIFS implementation.
 *  libnet smbconf registry Support
 *  Copyright (C) Michael Adam 2007-2008
 *  Copyright (C) Guenther Deschner 2007
 *
 *  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 "smbconf_private.h"

/**********************************************************************
 *
 * internal helper functions
 *
 **********************************************************************/

static int smbconf_destroy_ctx(struct smbconf_ctx *ctx)
{
	return ctx->ops->shutdown(ctx);
}

static WERROR smbconf_global_check(struct smbconf_ctx *ctx)
{
	if (!smbconf_share_exists(ctx, GLOBAL_NAME)) {
		return smbconf_create_share(ctx, GLOBAL_NAME);
	}
	return WERR_OK;
}


/**********************************************************************
 *
 * helper functions exported to the backend modules
 * (might go into a smbconf_util.c)
 *
 **********************************************************************/

/**
 * add a string to a talloced array of strings.
 */
 WERROR smbconf_add_string_to_array(TALLOC_CTX *mem_ctx,
				    char ***array,
				    uint32_t count,
				    const char *string)
{
	char **new_array = NULL;

	if ((array == NULL) || (string == NULL)) {
		return WERR_INVALID_PARAM;
	}

	new_array = TALLOC_REALLOC_ARRAY(mem_ctx, *array, char *, count + 1);
	if (new_array == NULL) {
		return WERR_NOMEM;
	}

	new_array[count] = talloc_strdup(new_array, string);
	if (new_array[count] == NULL) {
		TALLOC_FREE(new_array);
		return WERR_NOMEM;
	}

	*array = new_array;

	return WERR_OK;
}

/**
 * Initialize the configuration.
 *
 * This should be the first function in a sequence of calls to smbconf
 * functions:
 *
 * Upon success, this creates and returns the conf context
 * that should be passed around in subsequent calls to the other
 * smbconf functions.
 *
 * After the work with the configuration is completed, smbconf_shutdown()
 * should be called.
 */
WERROR smbconf_init(TALLOC_CTX *mem_ctx, struct smbconf_ctx **conf_ctx,
		    const char *path, struct smbconf_ops *ops)
{
	WERROR werr = WERR_OK;
	struct smbconf_ctx *ctx;

	if (conf_ctx == NULL) {
		return WERR_INVALID_PARAM;
	}

	ctx = TALLOC_ZERO_P(mem_ctx, struct smbconf_ctx);
	if (ctx == NULL) {
		return WERR_NOMEM;
	}

	ctx->ops = ops;

	werr = ctx->ops->init(ctx, path);
	if (!W_ERROR_IS_OK(werr)) {
		goto fail;
	}

	talloc_set_destructor(ctx, smbconf_destroy_ctx);

	*conf_ctx = ctx;
	return werr;

fail:
	TALLOC_FREE(ctx);
	return werr;
}


/**********************************************************************
 *
 * The actual libsmbconf API functions that are exported.
 *
 **********************************************************************/

/**
 * Close the configuration.
 */
void smbconf_shutdown(struct smbconf_ctx *ctx)
{
	TALLOC_FREE(ctx);
}

/**
 * Detect changes in the configuration.
 * The given csn struct is filled with the current csn.
 * smbconf_changed() can also be used for initial retrieval
 * of the csn.
 */
bool smbconf_changed(struct smbconf_ctx *ctx, struct smbconf_csn *csn,
		     const char *service, const char *param)
{
	struct smbconf_csn old_csn;

	if (csn == NULL) {
		return false;
	}

	old_csn = *csn;

	ctx->ops->get_csn(ctx, csn, service, param);
	return (csn->csn != old_csn.csn);
}

/**
 * Drop the whole configuration (restarting empty).
 */
WERROR smbconf_drop(struct smbconf_ctx *ctx)
{
	return ctx->ops->drop(ctx);
}

/**
 * Get the whole configuration as lists of strings with counts:
 *
 *  num_shares   : number of shares
 *  share_names  : list of length num_shares of share names
 *  num_params   : list of length num_shares of parameter counts for each share
 *  param_names  : list of lists of parameter names for each share
 *  param_values : list of lists of parameter values for each share
 */
WERROR smbconf_get_config(struct smbconf_ctx *ctx,
			  TALLOC_CTX *mem_ctx,
			  uint32_t *num_shares,
			  char ***share_names, uint32_t **num_params,
			  char ****param_names, char ****param_values)
{
	WERROR werr = WERR_OK;
	TALLOC_CTX *tmp_ctx = NULL;
	uint32_t tmp_num_shares;
	char **tmp_share_names;
	uint32_t *tmp_num_params;
	char ***tmp_param_names;
	char ***tmp_param_values;
	uint32_t count;

	if ((num_shares == NULL) || (share_names == NULL) ||
	    (num_params == NULL) || (param_names == NULL) ||
	    (param_values == NULL))
	{
		werr = WERR_INVALID_PARAM;
		goto done;
	}

	tmp_ctx = talloc_stackframe();
	if (tmp_ctx == NULL) {
		werr = WERR_NOMEM;
		goto done;
	}

	werr = smbconf_get_share_names(ctx, tmp_ctx, &tmp_num_shares,
				       &tmp_share_names);
	if (!W_ERROR_IS_OK(werr)) {
		goto done;
	}

	tmp_num_params   = TALLOC_ARRAY(tmp_ctx, uint32_t, tmp_num_shares);
	tmp_param_names  = TALLOC_ARRAY(tmp_ctx, char **, tmp_num_shares);
	tmp_param_values = TALLOC_ARRAY(tmp_ctx, char **, tmp_num_shares);

	if ((tmp_num_params == NULL) || (tmp_param_names == NULL) ||
	    (tmp_param_values == NULL))
	{
		werr = WERR_NOMEM;
		goto done;
	}

	for (count = 0; count < tmp_num_shares; count++) {
		werr = smbconf_get_share(ctx, mem_ctx,
					 tmp_share_names[count],
					 &tmp_num_params[count],
					 &tmp_param_names[count],
					 &tmp_param_values[count]);
		if (!W_ERROR_IS_OK(werr)) {
			goto done;
		}
	}

	werr = WERR_OK;

	*num_shares = tmp_num_shares;
	if (tmp_num_shares > 0) {
		*share_names = talloc_move(mem_ctx, &tmp_share_names);
		*num_params = talloc_move(mem_ctx, &tmp_num_params);
		*param_names = talloc_move(mem_ctx, &tmp_param_names);
		*param_values = talloc_move(mem_ctx, &tmp_param_values);
	} else {
		*share_names = NULL;
		*num_params = NULL;
		*param_names = NULL;
		*param_values = NULL;
	}

done:
	TALLOC_FREE(tmp_ctx);
	return werr;
}

/**
 * get the list of share names defined in the configuration.
 */
WERROR smbconf_get_share_names(struct smbconf_ctx *ctx,
			       TALLOC_CTX *mem_ctx,
			       uint32_t *num_shares,
			       char ***share_names)
{
	return ctx->ops->get_share_names(ctx, mem_ctx, num_shares,
					 share_names);
}

/**
 * check if a share/service of a given name exists
 */
bool smbconf_share_exists(struct smbconf_ctx *ctx,
			  const char *servicename)
{
	if (servicename == NULL) {
		return false;
	}
	return ctx->ops->share_exists(ctx, servicename);
}

/**
 * Add a service if it does not already exist.
 */
WERROR smbconf_create_share(struct smbconf_ctx *ctx,
			    const char *servicename)
{
	if (smbconf_share_exists(ctx, servicename)) {
		return WERR_ALREADY_EXISTS;
	}

	return ctx->ops->create_share(ctx, servicename);
}

/**
 * get a definition of a share (service) from configuration.
 */
WERROR smbconf_get_share(struct smbconf_ctx *ctx,
			 TALLOC_CTX *mem_ctx,
			 const char *servicename, uint32_t *num_params,
			 char ***param_names, char ***param_values)
{
	if (!smbconf_share_exists(ctx, servicename)) {
		return WERR_NO_SUCH_SERVICE;
	}

	return ctx->ops->get_share(ctx, mem_ctx, servicename, num_params,
				   param_names, param_values);
}

/**
 * delete a service from configuration
 */
WERROR smbconf_delete_share(struct smbconf_ctx *ctx, const char *servicename)
{
	if (!smbconf_share_exists(ctx, servicename)) {
		return WERR_NO_SUCH_SERVICE;
	}

	return ctx->ops->delete_share(ctx, servicename);
}

/**
 * set a configuration parameter to the value provided.
 */
WERROR smbconf_set_parameter(struct smbconf_ctx *ctx,
			     const char *service,
			     const char *param,
			     const char *valstr)
{
	if (!smbconf_share_exists(ctx, service)) {
		return WERR_NO_SUCH_SERVICE;
	}

	return ctx->ops->set_parameter(ctx, service, param, valstr);
}

/**
 * Set a global parameter
 * (i.e. a parameter in the [global] service).
 *
 * This also creates [global] when it does not exist.
 */
WERROR smbconf_set_global_parameter(struct smbconf_ctx *ctx,
				    const char *param, const char *val)
{
	WERROR werr;

	werr = smbconf_global_check(ctx);
	if (W_ERROR_IS_OK(werr)) {
		werr = smbconf_set_parameter(ctx, GLOBAL_NAME, param, val);
	}

	return werr;
}

/**
 * get the value of a configuration parameter as a string
 */
WERROR smbconf_get_parameter(struct smbconf_ctx *ctx,
			     TALLOC_CTX *mem_ctx,
			     const char *service,
			     const char *param,
			     char **valstr)
{
	if (valstr == NULL) {
		return WERR_INVALID_PARAM;
	}

	if (!smbconf_share_exists(ctx, service)) {
		return WERR_NO_SUCH_SERVICE;
	}

	return ctx->ops->get_parameter(ctx, mem_ctx, service, param, valstr);
}

/**
 * Get the value of a global parameter.
 *
 * Create [global] if it does not exist.
 */
WERROR smbconf_get_global_parameter(struct smbconf_ctx *ctx,
				    TALLOC_CTX *mem_ctx,
				    const char *param,
				    char **valstr)
{
	WERROR werr;

	werr = smbconf_global_check(ctx);
	if (W_ERROR_IS_OK(werr)) {
		werr = smbconf_get_parameter(ctx, mem_ctx, GLOBAL_NAME, param,
					     valstr);
	}

	return werr;
}

/**
 * delete a parameter from configuration
 */
WERROR smbconf_delete_parameter(struct smbconf_ctx *ctx,
				const char *service, const char *param)
{
	if (!smbconf_share_exists(ctx, service)) {
		return WERR_NO_SUCH_SERVICE;
	}

	return ctx->ops->delete_parameter(ctx, service, param);
}

/**
 * Delete a global parameter.
 *
 * Create [global] if it does not exist.
 */
WERROR smbconf_delete_global_parameter(struct smbconf_ctx *ctx,
				       const char *param)
{
	WERROR werr;

	werr = smbconf_global_check(ctx);
	if (W_ERROR_IS_OK(werr)) {
		werr = smbconf_delete_parameter(ctx, GLOBAL_NAME, param);
	}

	return werr;
}