/**
 * @file Config.h
 * @brief Configuration management for the Locomotive Test Bench
 * 
 * This module handles persistent storage of WiFi and system settings
 * using ESP32's Preferences library (NVS - Non-Volatile Storage).
 * 
 * @author Locomotive Test Bench Project
 * @date 2025
 */

#ifndef CONFIG_H
#define CONFIG_H

#include <Arduino.h>
#include <Preferences.h>

/**
 * @struct WiFiConfig
 * @brief WiFi configuration parameters
 * 
 * Stores both Access Point and Client mode settings.
 */
struct WiFiConfig {
    String ssid;        ///< WiFi network SSID (Client mode)
    String password;    ///< WiFi network password (Client mode)
    bool isAPMode;      ///< True = AP mode, False = Client mode
    String apSSID;      ///< Access Point SSID
    String apPassword;  ///< Access Point password (min 8 characters)
};

/**
 * @struct SystemConfig
 * @brief System operation configuration
 * 
 * Stores current control mode and locomotive parameters.
 */
struct SystemConfig {
    bool isDCCMode;         ///< True = DCC digital, False = DC analog
    uint16_t dccAddress;    ///< DCC locomotive address (1-10239)
    uint8_t speed;          ///< Speed setting (0-100%)
    uint8_t direction;      ///< Direction: 0 = reverse, 1 = forward
    uint32_t dccFunctions;  ///< Bit field for DCC functions F0-F28
};

/**
 * @class Config
 * @brief Configuration manager with persistent storage
 * 
 * Manages all configuration parameters and provides persistent
 * storage using ESP32's NVS (Non-Volatile Storage) via Preferences.
 * 
 * @note All settings are automatically saved to flash memory
 * and persist across reboots.
 */
class Config {
public:
    /**
     * @brief Constructor - initializes with default values
     */
    Config();
    
    /**
     * @brief Initialize preferences and load saved settings
     * 
     * Must be called during setup() before using configuration.
     * Loads previously saved settings from NVS.
     */
    void begin();
    
    /**
     * @brief Save current configuration to NVS
     * 
     * Writes all WiFi and system settings to persistent storage.
     * Should be called after any configuration changes.
     */
    void save();
    
    /**
     * @brief Load configuration from NVS
     * 
     * Reads previously saved settings. Called automatically
     * by begin(), but can be called manually to reload.
     */
    void load();
    
    /**
     * @brief Reset all settings to defaults
     * 
     * Clears all stored preferences and resets to factory defaults.
     * Use with caution - all saved settings will be lost.
     */
    void reset();
    
    WiFiConfig wifi;      ///< WiFi configuration settings
    SystemConfig system;  ///< System operation settings

private:
    Preferences preferences;  ///< ESP32 NVS preferences object
};

#endif