#include <ESP8266WiFi.h>
#include <include/WiFiState.h>

auto sleepDuration{10'000UL};

void setup() {
    delay (3000);

    gpio_pin_wakeup_enable(D5, GPIO_PIN_INTR_HILEVEL);
    pinMode(LED_BUILTIN, OUTPUT);
    Serial.begin(9600);

    WiFi.mode(WIFI_OFF);
    wifi_fpm_set_sleep_type (LIGHT_SLEEP_T);
}

auto awakenTime{0UL};

void wakeup_cb()
{
    wifi_fpm_close();
    Serial.printf("cb reached: %lums\n", (awakenTime = millis()));
}

void loop()
{
    static auto awakeTime{0UL};
    static auto sleepTime{0UL};

    Serial.printf("going to sleep: %lums\n", (sleepTime = millis()));
    Serial.flush();

    wifi_set_opmode_current(NULL_MODE);
    wifi_fpm_set_sleep_type(LIGHT_SLEEP_T);
    wifi_fpm_set_wakeup_cb(wakeup_cb);
    wifi_fpm_open();
    wifi_fpm_do_sleep(sleepDuration * 1000);
    delay(sleepDuration + 1);
    Serial.printf("awake: %lums\n", (awakeTime = millis()));
}