#include "maze32_config_store.h"

#include <string.h>

#include "nvs.h"
#include "nvs_flash.h"

static const char *NAMESPACE = "maze32";
static const char *SCHEMA_KEY = "cfg_ver";
static const char *SSID_KEY = "wifi_ssid";
static const char *PASSWORD_KEY = "wifi_pass";

esp_err_t maze32_config_store_init(void)
{
    esp_err_t result = nvs_flash_init();
    if (result == ESP_ERR_NVS_NO_FREE_PAGES || result == ESP_ERR_NVS_NEW_VERSION_FOUND) {
        result = nvs_flash_erase();
        if (result == ESP_OK) {
            result = nvs_flash_init();
        }
    }
    return result;
}

esp_err_t maze32_config_store_load(maze32_wifi_credentials_t *credentials)
{
    if (credentials == NULL) {
        return ESP_ERR_INVALID_ARG;
    }

    nvs_handle_t handle;
    esp_err_t result = nvs_open(NAMESPACE, NVS_READONLY, &handle);
    if (result == ESP_ERR_NVS_NOT_FOUND) {
        return ESP_ERR_NOT_FOUND;
    }
    if (result != ESP_OK) {
        return result;
    }

    uint32_t schema_version = 0U;
    result = nvs_get_u32(handle, SCHEMA_KEY, &schema_version);
    if (result == ESP_OK && schema_version != MAZE32_WIFI_CONFIG_SCHEMA_VERSION) {
        result = ESP_ERR_INVALID_VERSION;
    }

    maze32_wifi_credentials_t loaded = {0};
    size_t ssid_size = sizeof(loaded.ssid);
    size_t password_size = sizeof(loaded.password);
    if (result == ESP_OK) {
        result = nvs_get_str(handle, SSID_KEY, loaded.ssid, &ssid_size);
    }
    if (result == ESP_OK) {
        result = nvs_get_str(handle, PASSWORD_KEY, loaded.password, &password_size);
    }
    nvs_close(handle);

    if (result == ESP_ERR_NVS_NOT_FOUND) {
        return ESP_ERR_NOT_FOUND;
    }

    if (result == ESP_OK &&
        maze32_wifi_credentials_validate(&loaded) != MAZE32_WIFI_CONFIG_VALID) {
        result = ESP_ERR_INVALID_STATE;
    }
    if (result == ESP_OK) {
        memcpy(credentials, &loaded, sizeof(*credentials));
    }
    return result;
}

esp_err_t maze32_config_store_save(const maze32_wifi_credentials_t *credentials)
{
    if (maze32_wifi_credentials_validate(credentials) != MAZE32_WIFI_CONFIG_VALID) {
        return ESP_ERR_INVALID_ARG;
    }

    nvs_handle_t handle;
    esp_err_t result = nvs_open(NAMESPACE, NVS_READWRITE, &handle);
    if (result != ESP_OK) {
        return result;
    }

    result = nvs_set_str(handle, SSID_KEY, credentials->ssid);
    if (result == ESP_OK) {
        result = nvs_set_str(handle, PASSWORD_KEY, credentials->password);
    }
    if (result == ESP_OK) {
        result = nvs_set_u32(handle, SCHEMA_KEY, MAZE32_WIFI_CONFIG_SCHEMA_VERSION);
    }
    if (result == ESP_OK) {
        result = nvs_commit(handle);
    }
    nvs_close(handle);
    return result;
}

esp_err_t maze32_config_store_clear(void)
{
    nvs_handle_t handle;
    esp_err_t result = nvs_open(NAMESPACE, NVS_READWRITE, &handle);
    if (result != ESP_OK) {
        return result;
    }
    result = nvs_erase_all(handle);
    if (result == ESP_OK) {
        result = nvs_commit(handle);
    }
    nvs_close(handle);
    return result;
}