/**
 * @file nvs_config.c
 * @brief Runtime configuration via NVS (Non-Volatile Storage).
 *
 * Checks NVS namespace "csi_cfg" for keys: ssid, password, target_ip,
 * target_port, node_id.  Falls back to Kconfig defaults when absent.
 */

#include "nvs_config.h"

#include <string.h>
#include "esp_log.h"
#include "nvs_flash.h"
#include "nvs.h"
#include "sdkconfig.h"

static const char *TAG = "nvs_config";

void nvs_config_load(nvs_config_t *cfg)
{
    /* Start with Kconfig compiled defaults */
    strncpy(cfg->wifi_ssid, CONFIG_CSI_WIFI_SSID, NVS_CFG_SSID_MAX - 1);
    cfg->wifi_ssid[NVS_CFG_SSID_MAX - 1] = '\0';

#ifdef CONFIG_CSI_WIFI_PASSWORD
    strncpy(cfg->wifi_password, CONFIG_CSI_WIFI_PASSWORD, NVS_CFG_PASS_MAX - 1);
    cfg->wifi_password[NVS_CFG_PASS_MAX - 1] = '\0';
#else
    cfg->wifi_password[0] = '\0';
#endif

    strncpy(cfg->target_ip, CONFIG_CSI_TARGET_IP, NVS_CFG_IP_MAX - 1);
    cfg->target_ip[NVS_CFG_IP_MAX - 1] = '\0';

    cfg->target_port = (uint16_t)CONFIG_CSI_TARGET_PORT;
    cfg->node_id     = (uint8_t)CONFIG_CSI_NODE_ID;

    /* Try to override from NVS */
    nvs_handle_t handle;
    esp_err_t err = nvs_open("csi_cfg", NVS_READONLY, &handle);
    if (err != ESP_OK) {
        ESP_LOGI(TAG, "No NVS config found, using compiled defaults");
        return;
    }

    size_t len;
    char buf[NVS_CFG_PASS_MAX];

    /* WiFi SSID */
    len = sizeof(buf);
    if (nvs_get_str(handle, "ssid", buf, &len) == ESP_OK && len > 1) {
        strncpy(cfg->wifi_ssid, buf, NVS_CFG_SSID_MAX - 1);
        cfg->wifi_ssid[NVS_CFG_SSID_MAX - 1] = '\0';
        ESP_LOGI(TAG, "NVS override: ssid=%s", cfg->wifi_ssid);
    }

    /* WiFi password */
    len = sizeof(buf);
    if (nvs_get_str(handle, "password", buf, &len) == ESP_OK) {
        strncpy(cfg->wifi_password, buf, NVS_CFG_PASS_MAX - 1);
        cfg->wifi_password[NVS_CFG_PASS_MAX - 1] = '\0';
        ESP_LOGI(TAG, "NVS override: password=***");
    }

    /* Target IP */
    len = sizeof(buf);
    if (nvs_get_str(handle, "target_ip", buf, &len) == ESP_OK && len > 1) {
        strncpy(cfg->target_ip, buf, NVS_CFG_IP_MAX - 1);
        cfg->target_ip[NVS_CFG_IP_MAX - 1] = '\0';
        ESP_LOGI(TAG, "NVS override: target_ip=%s", cfg->target_ip);
    }

    /* Target port */
    uint16_t port_val;
    if (nvs_get_u16(handle, "target_port", &port_val) == ESP_OK) {
        cfg->target_port = port_val;
        ESP_LOGI(TAG, "NVS override: target_port=%u", cfg->target_port);
    }

    /* Node ID */
    uint8_t node_val;
    if (nvs_get_u8(handle, "node_id", &node_val) == ESP_OK) {
        cfg->node_id = node_val;
        ESP_LOGI(TAG, "NVS override: node_id=%u", cfg->node_id);
    }

    nvs_close(handle);
}