#include "pod_settings.h"
#include "bosch456.h"
#include "esp_log.h"
#include "nvs.h"
#include "nvs_flash.h"

static const char *TAG = "[SETTINGS]";
static const char *NS = "powerpod";
static const char *KEY_ACCEL_DZ = "accel_dz";

#define ACCEL_DEADZONE_MAX 4095u

static bool s_nvs_ready;

static esp_err_t ensure_nvs(void) {
  if (s_nvs_ready) {
    return ESP_OK;
  }
  return pod_settings_init();
}

esp_err_t pod_settings_init(void) {
  if (s_nvs_ready) {
    return ESP_OK;
  }

  esp_err_t err = nvs_flash_init();
  if (err == ESP_ERR_NVS_NO_FREE_PAGES ||
      err == ESP_ERR_NVS_NEW_VERSION_FOUND) {
    ESP_LOGW(TAG, "NVS erase and re-init");
    ESP_ERROR_CHECK(nvs_flash_erase());
    err = nvs_flash_init();
  }
  if (err != ESP_OK) {
    ESP_LOGE(TAG, "nvs_flash_init failed: %s", esp_err_to_name(err));
    return err;
  }

  s_nvs_ready = true;
  ESP_LOGI(TAG, "NVS ready, accel deadzone %lu LSB (stored)",
           (unsigned long)pod_settings_load_accel_deadzone());
  return ESP_OK;
}

uint32_t pod_settings_load_accel_deadzone(void) {
  if (!s_nvs_ready) {
    return BMA456_DEFAULT_ACCEL_DEADZONE;
  }

  nvs_handle_t handle;
  esp_err_t err = nvs_open(NS, NVS_READONLY, &handle);
  if (err != ESP_OK) {
    return BMA456_DEFAULT_ACCEL_DEADZONE;
  }

  uint32_t value = BMA456_DEFAULT_ACCEL_DEADZONE;
  err = nvs_get_u32(handle, KEY_ACCEL_DZ, &value);
  nvs_close(handle);

  if (err == ESP_ERR_NVS_NOT_FOUND) {
    return BMA456_DEFAULT_ACCEL_DEADZONE;
  }
  if (err != ESP_OK) {
    ESP_LOGW(TAG, "read accel_dz failed: %s", esp_err_to_name(err));
    return BMA456_DEFAULT_ACCEL_DEADZONE;
  }
  if (value > ACCEL_DEADZONE_MAX) {
    return BMA456_DEFAULT_ACCEL_DEADZONE;
  }
  return value;
}

esp_err_t pod_settings_save_accel_deadzone(uint32_t deadzone_lsb) {
  if (deadzone_lsb > ACCEL_DEADZONE_MAX) {
    return ESP_ERR_INVALID_ARG;
  }

  esp_err_t err = ensure_nvs();
  if (err != ESP_OK) {
    return err;
  }

  nvs_handle_t handle;
  err = nvs_open(NS, NVS_READWRITE, &handle);
  if (err != ESP_OK) {
    ESP_LOGE(TAG, "nvs_open failed: %s", esp_err_to_name(err));
    return err;
  }

  err = nvs_set_u32(handle, KEY_ACCEL_DZ, deadzone_lsb);
  if (err == ESP_OK) {
    err = nvs_commit(handle);
  }
  nvs_close(handle);

  if (err != ESP_OK) {
    ESP_LOGE(TAG, "save accel_dz failed: %s", esp_err_to_name(err));
    return err;
  }

  ESP_LOGI(TAG, "saved accel deadzone %lu LSB", (unsigned long)deadzone_lsb);
  return ESP_OK;
}

void pod_settings_apply_accel_deadzone(void) {
  uint32_t deadzone = pod_settings_load_accel_deadzone();
  if (bma456_is_ready()) {
    bma456_set_accel_deadzone(deadzone);
  }
}