// SPDX-License-Identifier: LGPL-2.1+

/*

 * Copyright (C) 2019 Red Hat, Inc.

 */

#include "nm-default.h"

#include "nm-keyfile-aux.h"

#include <syslog.h>

#include <sys/stat.h>

#include <fcntl.h>

#include "nm-io-utils.h"

/*****************************************************************************/

struct _NMKeyFileDB {

	NMKeyFileDBLogFcn log_fcn;

	NMKeyFileDBGotDirtyFcn got_dirty_fcn;

	gpointer user_data;

	const char *group_name;

	GKeyFile *kf;

	guint ref_count;

	bool is_started:1;

	bool dirty:1;

	bool destroyed:1;

	char filename[];

};

#define _NMLOG(self, \

               syslog_level, \

               fmt, \

               ...) \

	G_STMT_START { \

		NMKeyFileDB *_self = (self); \

		\

		nm_assert (_self); \

		nm_assert (!_self->destroyed); \

		\

		if (_self->log_fcn) { \

			_self->log_fcn (_self, \

			                (syslog_level), \

			                _self->user_data, \

			                ""fmt"", \

			                ##__VA_ARGS__); \

		}; \

	} G_STMT_END

#define _LOGD(...) _NMLOG (self, LOG_DEBUG, __VA_ARGS__)

static gboolean

_IS_KEY_FILE_DB (NMKeyFileDB *self, gboolean require_is_started, gboolean allow_destroyed)

{

	if (self == NULL)

		return FALSE;

	if (self->ref_count <= 0) {

		nm_assert_not_reached ();

		return FALSE;

	}

	if (   require_is_started

	    && !self->is_started)

		return FALSE;

	if (   !allow_destroyed

	    && self->destroyed)

		return FALSE;

	return TRUE;

}

/*****************************************************************************/

NMKeyFileDB *

nm_key_file_db_new (const char *filename,

                    const char *group_name,

                    NMKeyFileDBLogFcn log_fcn,

                    NMKeyFileDBGotDirtyFcn got_dirty_fcn,

                    gpointer user_data)

{

	NMKeyFileDB *self;

	gsize l_filename;

	gsize l_group;

	g_return_val_if_fail (filename && filename[0], NULL);

	g_return_val_if_fail (group_name && group_name[0], NULL);

	l_filename = strlen (filename);

	l_group = strlen (group_name);

	self = g_malloc0 (sizeof (NMKeyFileDB) + l_filename + 1 + l_group + 1);

	self->ref_count = 1;

	self->log_fcn = log_fcn;

	self->got_dirty_fcn = got_dirty_fcn;

	self->user_data = user_data;

	self->kf = g_key_file_new ();

	g_key_file_set_list_separator (self->kf, ',');

	memcpy (self->filename, filename, l_filename + 1);

	self->group_name = &self->filename[l_filename + 1];

	memcpy ((char *) self->group_name, group_name, l_group + 1);

	return self;

}

NMKeyFileDB *

nm_key_file_db_ref (NMKeyFileDB *self)

{

	if (!self)

		return NULL;

	g_return_val_if_fail (_IS_KEY_FILE_DB (self, FALSE, TRUE), NULL);

	nm_assert (self->ref_count < G_MAXUINT);

	self->ref_count++;

	return self;

}

void

nm_key_file_db_unref (NMKeyFileDB *self)

{

	if (!self)

		return;

	g_return_if_fail (_IS_KEY_FILE_DB (self, FALSE, TRUE));

	if (--self->ref_count > 0)

		return;

	g_key_file_unref (self->kf);

	g_free (self);

}

/* destroy() is like unref, but it also makes the instance unusable.

 * All changes afterwards fail with an assertion.

 *

 * The point is that NMKeyFileDB is ref-counted in principle. But there

 * is a primary owner who also provides the log_fcn().

 *

 * When the primary owner goes out of scope and gives up the reference, it does

 * not want to receive any log notifications anymore.

 *

 * The way NMKeyFileDB is intended to be used is in a very strict context:

 * NMSettings owns the NMKeyFileDB instance and receives logging notifications.

 * It's also the last one to persist the data to disk. Afterwards, no other user

 * is supposed to be around and do anything with NMKeyFileDB. But since NMKeyFileDB

 * is ref-counted it's hard to ensure that this is truly honored. So we start

 * asserting at that point.

 */

void

nm_key_file_db_destroy (NMKeyFileDB *self)

{

	if (!self)

		return;

	g_return_if_fail (_IS_KEY_FILE_DB (self, FALSE, FALSE));

	g_return_if_fail (!self->destroyed);

	self->destroyed = TRUE;

	nm_key_file_db_unref (self);

}

/*****************************************************************************/

/* nm_key_file_db_start() is supposed to be called right away, after creating the

 * instance.

 *

 * It's not done as separate step after nm_key_file_db_new(), because we want to log,

 * and the log_fcn returns the self pointer (which we should not expose before

 * nm_key_file_db_new() returns. */

void

nm_key_file_db_start (NMKeyFileDB *self)

{

	gs_free char *contents = NULL;

	gsize contents_len;

	gs_free_error GError *error = NULL;

	g_return_if_fail (_IS_KEY_FILE_DB (self, FALSE, FALSE));

	g_return_if_fail (!self->is_started);

	self->is_started = TRUE;

	if (!nm_utils_file_get_contents (-1,

	                                 self->filename,

	                                 20*1024*1024,

	                                 NM_UTILS_FILE_GET_CONTENTS_FLAG_NONE,

	                                 &contents,

	                                 &contents_len,

	                                 NULL,

	                                 &error)) {

		_LOGD ("failed to read \"%s\": %s", self->filename, error->message);

		return;

	}

	if (!g_key_file_load_from_data (self->kf,

	                                contents,

	                                contents_len,

	                                G_KEY_FILE_KEEP_COMMENTS,

	                                &error)) {

		_LOGD ("failed to load keyfile \"%s\": %s", self->filename, error->message);

		return;

	}

	_LOGD ("loaded keyfile-db for \"%s\"", self->filename);

}

/*****************************************************************************/

const char *

nm_key_file_db_get_filename (NMKeyFileDB *self)

{

	g_return_val_if_fail (_IS_KEY_FILE_DB (self, FALSE, TRUE), NULL);

	return self->filename;

}

gboolean

nm_key_file_db_is_dirty (NMKeyFileDB *self)

{

	g_return_val_if_fail (_IS_KEY_FILE_DB (self, FALSE, TRUE), FALSE);

	return self->dirty;

}

/*****************************************************************************/

char *

nm_key_file_db_get_value (NMKeyFileDB *self,

                          const char *key)

{

	g_return_val_if_fail (_IS_KEY_FILE_DB (self, TRUE, TRUE), NULL);

	return g_key_file_get_value (self->kf, self->group_name, key, NULL);

}

char **

nm_key_file_db_get_string_list (NMKeyFileDB *self,

                                const char *key,

                                gsize *out_len)

{

	g_return_val_if_fail (_IS_KEY_FILE_DB (self, TRUE, TRUE), NULL);

	return g_key_file_get_string_list (self->kf, self->group_name, key, out_len, NULL);

}

/*****************************************************************************/

static void

_got_dirty (NMKeyFileDB *self,

            const char *key)

{

	nm_assert (_IS_KEY_FILE_DB (self, TRUE, FALSE));

	nm_assert (!self->dirty);

	_LOGD ("updated entry for %s.%s", self->group_name, key);

	self->dirty = TRUE;

	if (self->got_dirty_fcn)

		self->got_dirty_fcn (self, self->user_data);

}

/*****************************************************************************/

void

nm_key_file_db_remove_key (NMKeyFileDB *self,

                           const char *key)

{

	gboolean got_dirty = FALSE;

	g_return_if_fail (_IS_KEY_FILE_DB (self, TRUE, FALSE));

	if (!key)

		return;

	if (!self->dirty) {

		gs_free_error GError *error = NULL;

		g_key_file_has_key (self->kf, self->group_name, key, &error);

		got_dirty = (error != NULL);

	}

	g_key_file_remove_key (self->kf, self->group_name, key, NULL);

	if (got_dirty)

		_got_dirty (self, key);

}

void

nm_key_file_db_set_value (NMKeyFileDB *self,

                          const char *key,

                          const char *value)

{

	gs_free char *old_value = NULL;

	gboolean got_dirty = FALSE;

	g_return_if_fail (_IS_KEY_FILE_DB (self, TRUE, FALSE));

	g_return_if_fail (key);

	if (!value) {

		nm_key_file_db_remove_key (self, key);

		return;

	}

	if (!self->dirty) {

		gs_free_error GError *error = NULL;

		old_value = g_key_file_get_value (self->kf, self->group_name, key, &error);

		if (error)

			got_dirty = TRUE;

	}

	g_key_file_set_value (self->kf, self->group_name, key, value);

	if (   !self->dirty

	    && !got_dirty) {

		gs_free_error GError *error = NULL;

		gs_free char *new_value = NULL;

		new_value = g_key_file_get_value (self->kf, self->group_name, key, &error);

		if (   error

		    || !new_value

		    || !nm_streq0 (old_value, new_value))

			got_dirty = TRUE;

	}

	if (got_dirty)

		_got_dirty (self, key);

}

void

nm_key_file_db_set_string_list (NMKeyFileDB *self,

                                const char *key,

                                const char *const*value,

                                gssize len)

{

	gs_free char *old_value = NULL;

	gboolean got_dirty = FALSE;;

	g_return_if_fail (_IS_KEY_FILE_DB (self, TRUE, FALSE));

	g_return_if_fail (key);

	if (!value) {

		nm_key_file_db_remove_key (self, key);

		return;

	}

	if (!self->dirty) {

		gs_free_error GError *error = NULL;

		old_value = g_key_file_get_value (self->kf, self->group_name, key, &error);

		if (error)

			got_dirty = TRUE;

	}

	if (len < 0)

		len = NM_PTRARRAY_LEN (value);

	g_key_file_set_string_list (self->kf, self->group_name, key, value, len);

	if (   !self->dirty

	    && !got_dirty) {

		gs_free_error GError *error = NULL;

		gs_free char *new_value = NULL;

		new_value = g_key_file_get_value (self->kf, self->group_name, key, &error);

		if (   error

		    || !new_value

		    || !nm_streq0 (old_value, new_value))

			got_dirty = TRUE;

	}

	if (got_dirty)

		_got_dirty (self, key);

}

/*****************************************************************************/

void

nm_key_file_db_to_file (NMKeyFileDB *self,

                        gboolean force)

{

	gs_free_error GError *error = NULL;

	g_return_if_fail (_IS_KEY_FILE_DB (self, TRUE, FALSE));

	if (   !force

	    && !self->dirty)

		return;

	self->dirty = FALSE;

	if (!g_key_file_save_to_file (self->kf,

	                              self->filename,

	                              &error)) {

		_LOGD ("failure to write keyfile \"%s\": %s", self->filename, error->message);

	} else

		_LOGD ("write keyfile: \"%s\"", self->filename);

}