/*
 * SPDX-License-Identifier: AGPL-3.0-only
 * Copyright (c) Camden Dixie O'Brien
 */

#ifndef CONFIG_H
#define CONFIG_H

#include <stddef.h>

#define CONFIG_MAX_VALUE_SIZE 32U

/**
 * Callback type for config updates
 */
typedef void (*ConfigCallback)(const char *value);

/**
 * Initialize the configuration module.
 *
 * If there is a saved configuration, it will be loaded. Otherwise,
 * the default configuration will be loaded and saved.
 */
void config_init(void);

/**
 * Set the device's hostname.
 *
 * The argument should be a null-terminated string. If the maximum
 * length is exceeded, the value will still be used, but will be
 * truncated.
 */
void config_set_hostname(const char *hostname);

/**
 * Write the device's hostname into the given buffer.
 *
 * The length of the hostname is returned. If the value's size exceeds
 * the size of the buffer, nothing will be written to the buffer but
 * the length is still returned.
 */
size_t config_get_hostname(char *buffer, size_t buffer_size);

/**
 * Add a callback for hostname updates.
 *
 * The function specified in the argument will be invoked whenever a
 * the hostname is updated, with the new value as its argument. The
 * lifetime of the passed argument will be static, but the value may
 * be modified once the callback returns.
 */
void config_add_hostname_callback(ConfigCallback callback);

#endif