#include "hw/hw_led.h"
#include "tcp_socket.h"

#include <cfg/debug.h>

#include <cpu/irq.h>
#include <cpu/power.h>

#include <drv/timer.h>
#include <drv/ser.h>

#include <kern/proc.h>
#include <kern/monitor.h>

#include <netif/ethernetif.h>

#include <lwip/ip.h>
#include <lwip/ip_addr.h>
#include <lwip/netif.h>
#include <lwip/tcpip.h>
#include <lwip/dhcp.h>

#include <stdio.h> // vsnprintf
#include <stdarg.h> // va_list

/* Network interface global variables */
static struct ip_addr ipaddr, netmask, gw;
static struct netif netif;

static void init(void)
{
	/* Enable all the interrupts */
	IRQ_ENABLE;

	/* Initialize debugging module (allow kprintf(), etc.) */
	kdbg_init();
	/* Initialize system timer */
	timer_init();

	proc_init();

	/* Initialize TCP/IP stack */
	tcpip_init(NULL, NULL);

	/* Bring up the network interface */
	netif_add(&netif, &ipaddr, &netmask, &gw, NULL, ethernetif_init, ip_input);
	netif_set_default(&netif);
	netif_set_up(&netif);
}

static char linebuf[200];

#define COMMAND_PORT 20000
static char readbuf[200];
static int protocol_run(int sockfd)
{
	ssize_t rd = lwip_recv(sockfd, readbuf, sizeof(readbuf), 0);
	// if rd == 0, the other end has performed an orderly shutdown
	if (rd == 0)
	{
		kprintf("Peer closed the connection\n");
		return -1;
	}

	// terminate the string and remove \n at end
	readbuf[rd - 1] = '\n';

	int len = snprintf(linebuf, sizeof(linebuf), "%s\r\n", readbuf);
	lwip_send(sockfd, linebuf, len, 0);
	return 0;
}

int main(void)
{
	init();

	dhcp_start(&netif);
	while (!netif.ip_addr.addr)
	{
		dhcp_fine_tmr();
		timer_delay(DHCP_FINE_TIMER_MSECS);
	}
	kprintf(">>> dhcp ok: ip = %s (kernel %s)\n",
		ip_ntoa(&netif.ip_addr.addr),
		CONFIG_KERN_PREEMPT ? "preempt" : "coop");

	int server = -1;
	struct sockaddr_in addr;
	server = lwip_socket(AF_INET, SOCK_STREAM, 0);
	if (server < 0)
		kprintf("Error opening socket\n");

	memset(&addr, 0, sizeof(addr));
	addr.sin_family = AF_INET;
	addr.sin_port = htons(COMMAND_PORT);
	addr.sin_addr.s_addr = INADDR_ANY;
	if (lwip_bind(server, (struct sockaddr *)&addr, sizeof(addr)) == -1)
		kprintf("Error binding port %hd\n", COMMAND_PORT);

	if (lwip_listen(server, 1) == -1)
		kprintf("Error listen\n");

	while (1)
	{
		bool done = false;
		int protocol_sock = lwip_accept(server, NULL, NULL);
		if (protocol_sock == -1)
		{
			kprintf("Error accepting connection\n");
			continue;
		}

		kprintf("Accepted connection on socket %d\n", protocol_sock);
		while (!done)
		{
			if (protocol_run(protocol_sock))
			{
				done = true;
			}
		}
		lwip_close(protocol_sock);
		kprintf("Closing socket %d\n", protocol_sock);
	}
}