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

#include "time_storage.h"

#include "esp_log.h"
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "nvs_flash.h"
#include <sys/time.h>

#define TAG "Time storage"

#define NVS_NAMESPACE "time"
#define TIMESTAMP_KEY "timestamp"

static void time_saver_func(void *arg)
{
	(void)arg;
	const TickType_t delay = CONFIG_TIME_SAVE_PERIOD_MS / portTICK_PERIOD_MS;
	while (1) {
		time_storage_save();
		vTaskDelay(delay);
	}
}

void time_storage_init()
{
	esp_err_t error;
	nvs_handle_t nvs;
	error = nvs_open(NVS_NAMESPACE, NVS_READONLY, &nvs);
	if (error == ESP_OK) {
		uint64_t timestamp;
		error = nvs_get_u64(nvs, TIMESTAMP_KEY, &timestamp);
		if (error == ESP_OK) {
			struct timeval tv = { .tv_sec = (time_t)timestamp };
			settimeofday(&tv, NULL);
		} else {
			if (error != ESP_ERR_NVS_NOT_FOUND)
				ESP_LOGE(TAG, "Error getting stored time: %04x", error);
		}
		nvs_close(nvs);
	} else {
		if (error != ESP_ERR_NVS_NOT_FOUND)
			ESP_LOGE(TAG, "Error opening NVS: %04x", error);
	}

	(void)xTaskCreate(
	    &time_saver_func, "time saver", CONFIG_DEFAULT_TASK_STACK, NULL, 1,
	    NULL);
}

void time_storage_save()
{
	esp_err_t error;

	nvs_handle_t nvs;
	error = nvs_open(NVS_NAMESPACE, NVS_READWRITE, &nvs);
	if (error != ESP_OK) {
		ESP_LOGE(TAG, "Error opening NVS: %04x", error);
		return;
	}

	struct timeval tv;
	gettimeofday(&tv, NULL);
	error = nvs_set_u64(nvs, TIMESTAMP_KEY, tv.tv_sec);
	if (error != ESP_OK)
		ESP_LOGE(TAG, "Error storing time: %04x", error);

	nvs_close(nvs);
}