#include <string.h>

#include "pico/stdlib.h"
#include "pico/cyw43_arch.h"

#include "lwip/netif.h"
#include "lwip/udp.h"
#include "lwip/pbuf.h"
#include "lwip/ip_addr.h"
#include "lwip/dhcp.h"

#include "wifi-settings.h"

static struct udp_pcb *udp;
static ip_addr_t dest_ip;

extern struct netif *netif_default;

static void send_hello(void) {
	const char msg[] = "hello world\n";

	struct pbuf *p = pbuf_alloc(PBUF_TRANSPORT, sizeof(msg) - 1, PBUF_RAM);
	if (!p) {
		return;
	}

	memcpy(p->payload, msg, sizeof(msg) - 1);
	udp_sendto(udp, p, &dest_ip, 5505);
	pbuf_free(p);
}

int main() {
	stdio_init_all();

	if (cyw43_arch_init()) {
		return -1;
	}

	cyw43_arch_enable_sta_mode();

	if (cyw43_arch_wifi_connect_timeout_ms(
			WIFI_SSID,
			WIFI_PASS,
			CYW43_AUTH_WPA2_AES_PSK,
			30000)) {
		return -1;
	}

	/* Raw lwIP setup */
	udp = udp_new_ip_type(IPADDR_TYPE_V4);
	if (!udp) {
		return -1;
	}

	ipaddr_aton("192.168.2.99", &dest_ip);

	absolute_time_t next = get_absolute_time();

	bool dhcp_done = false;

	while (true) {
		cyw43_arch_poll();

		if (!dhcp_done) {
			if (netif_default &&
				netif_is_up(netif_default) &&
				!ip4_addr_isany_val(*netif_ip4_addr(netif_default))) {

				dhcp_done = true;
				cyw43_arch_gpio_put(CYW43_WL_GPIO_LED_PIN, 1);
			}
		}

		if (absolute_time_diff_us(get_absolute_time(), next) <= 0) {
			send_hello();
			next = delayed_by_ms(next, 1000);
		}

		sleep_ms(1);
	}
}