#include "hardware/clocks.h"
#include "hardware/rtc.h"
#include "hardware/spi.h"
#include "hardware/timer.h"
#include "lwip/apps/sntp.h"
#include "lwip/err.h"
#include "lwip/ip_addr.h"
#include "pico/cyw43_arch.h"
#include "pico/stdlib.h"
#include "pico/util/datetime.h"
#include "wifi_conf.h"
#include <lwip/arch.h>
#include <pico/stdio.h>
#include <stdio.h>

#include "lwip/dns.h"
#include "lwip/init.h"
#include "lwip/tcp.h"
#include "net_utils.h"

// SPI Defines
// We are going to use SPI 0, and allocate it to the following GPIO pins
// Pins can be changed, see the GPIO function select table in the datasheet for
// information on GPIO assignments
#define SPI_PORT spi0
#define PIN_MISO 16
#define PIN_CS 17
#define PIN_SCK 18
#define PIN_MOSI 19

extern "C" void sync_system_time(unsigned int sec, unsigned int usec) {
  printf("SNTP callback received: %lu\n", (unsigned long)sec);
  time_t unix_time = (time_t)sec;

  u16_t timezone_offset = 7200;

  // Apply timezone offset for local time
  unix_time += timezone_offset;

  struct tm *time_info = gmtime(&unix_time);
  if (time_info == NULL) {
    printf("SNTP: Invalid timestamp %lu\n", (unsigned long)sec);
    return;
  }

  datetime_t dt = {.year = static_cast<int16_t>(time_info->tm_year + 1900),
                   .month = static_cast<int8_t>(time_info->tm_mon + 1),
                   .day = static_cast<int8_t>(time_info->tm_mday),
                   .dotw = static_cast<int8_t>(time_info->tm_wday),
                   .hour = static_cast<int8_t>(time_info->tm_hour),
                   .min = static_cast<int8_t>(time_info->tm_min),
                   .sec = static_cast<int8_t>(time_info->tm_sec)};

  // Sanity checks
  if (dt.year < 2020 || dt.year > 2100 || dt.month < 1 || dt.month > 12 ||
      dt.day < 1 || dt.day > 31 || dt.hour > 23 || dt.min > 59 || dt.sec > 59) {
    printf("SNTP: Invalid date/time components\n");
    return;
  }

  // Set RTC
  if (rtc_set_datetime(&dt)) {
    printf("SNTP: Time set to %04d-%02d-%02d %02d:%02d:%02d %s\n", dt.year,
           dt.month, dt.day, dt.hour, dt.min, dt.sec,
           (timezone_offset == 0) ? "UTC" : "Local");
  } else {
    printf("SNTP: Failed to set RTC\n");
  }
}

int main() {
  stdio_init_all();
  if (cyw43_arch_init()) {
    return 1;
  }
  rtc_init();

  // sign of life
  cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, true);

  // SPI initialisation. This example will use SPI at 1MHz.
  spi_init(SPI_PORT, 1000 * 1000);
  gpio_set_function(PIN_MISO, GPIO_FUNC_SPI);
  gpio_set_function(PIN_CS, GPIO_FUNC_SIO);
  gpio_set_function(PIN_SCK, GPIO_FUNC_SPI);
  gpio_set_function(PIN_MOSI, GPIO_FUNC_SPI);

  // Chip select is active-low, so we'll initialise it to a driven-high state
  gpio_set_dir(PIN_CS, GPIO_OUT);
  gpio_put(PIN_CS, 1);

  // Timer example code - This example fires off the callback after 2000ms
  // add_alarm_in_ms(2000, alarm_callback, NULL, false);

  printf("connecting to wifi\n");
  // connect to wifi
  cyw43_arch_enable_sta_mode();
  if (cyw43_arch_wifi_connect_timeout_ms(wifi_ssid, wifi_pass,
                                         CYW43_AUTH_WPA2_AES_PSK, 30000)) {
    return 1;
  }

  printf("IP: %s\n", ip4addr_ntoa(netif_ip_addr4(netif_default)));
  printf("Mask: %s\n", ip4addr_ntoa(netif_ip_netmask4(netif_default)));
  printf("Gateway: %s\n", ip4addr_ntoa(netif_ip_gw4(netif_default)));

  {
    ip_addr_t ip_addr;
    IP_ADDR4(&ip_addr, 1, 1, 1, 1);
    dns_setserver(0, &ip_addr);

    IP_ADDR4(&ip_addr, 8, 8, 8, 8);
    dns_setserver(1, &ip_addr);

    printf("Initializing SNTP\n");
    sntp_setoperatingmode(SNTP_OPMODE_POLL);
    sntp_init();

    dns_resolve_sync("ntp.cesnet.cz", &ip_addr, 10000);
    sntp_setserver(0, &ip_addr);

    dns_resolve_sync("ntp0.fau.de", &ip_addr, 10000);
    sntp_setserver(1, &ip_addr);
  }

  printf("SNTP initialized, waiting for time sync...\n");

  while (true) {

    // Keep the program running to allow SNTP to work
    sleep_ms(1000);

    // Optional: Print current time periodically to verify sync
    datetime_t t;
    if (rtc_get_datetime(&t)) {
      printf("Current time: %04d-%02d-%02d %02d:%02d:%02d\n", t.year, t.month,
             t.day, t.hour, t.min, t.sec);
    } else {
      printf("failed to get rtc\n");
    }
  }
  cyw43_arch_lwip_end();
  return 0;
}