#include <sys/socket.h>
#include <arpa/inet.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>


#include <ev.h>

#include "list.h"
#include "log.h"
#include "pingu_burst.h"
#include "pingu_host.h"
#include "pingu_iface.h"
#include "pingu_ping.h"

static struct list_head iface_list = LIST_INITIALIZER(iface_list);

static void pingu_iface_socket_cb(struct ev_loop *loop, struct ev_io *w,
				 int revents)
{
	struct pingu_iface *iface = container_of(w, struct pingu_iface, socket_watcher);

	if (revents & EV_READ)
		pingu_ping_read_reply(loop, iface);
}

int pingu_iface_bind_socket(struct pingu_iface *iface, int log_error)
{
	int r;
	if (iface->name[0] == '\0')
		return 0;
	r = setsockopt(iface->fd, SOL_SOCKET, SO_BINDTODEVICE, iface->name,
		       strlen(iface->name));
	if (r < 0 && log_error)
		log_perror(iface->name);
	iface->has_binding = (r == 0);
	return r;
}

static int pingu_iface_init_socket(struct ev_loop *loop,
				   struct pingu_iface *iface)
{
	iface->fd = socket(AF_INET, SOCK_RAW, IPPROTO_ICMP);
	if (iface->fd < 0) {
		log_perror("socket");
		return -1;
	}

	ev_io_init(&iface->socket_watcher, pingu_iface_socket_cb, iface->fd, EV_READ);
	ev_io_start(loop, &iface->socket_watcher);
	pingu_iface_bind_socket(iface, 1);
	return 0;
}

struct pingu_iface *pingu_iface_find(const char *name)
{
	struct pingu_iface *iface;
	list_for_each_entry(iface, &iface_list, iface_list_entry) {
		if (name == NULL) {
			if (iface->name[0] == '\n')
				return iface;
		} else if (strncmp(name, iface->name, sizeof(iface->name)) == 0)
			return iface;
	}
	return NULL;
}

struct pingu_iface *pingu_iface_find_or_create(struct ev_loop *loop, const char *name)
{
	struct pingu_iface *iface = pingu_iface_find(name);
	if (iface != NULL)
		return iface;

	iface = calloc(1, sizeof(struct pingu_iface));
	if (iface == NULL) {
		log_perror("calloc(iface)");
		return NULL;
	}

	if (name != NULL)
		strlcpy(iface->name, name, sizeof(iface->name));
	
	if (pingu_iface_init_socket(loop, iface) == -1) {
		free(iface);
		return NULL;
	}
	list_init(&iface->ping_list);
	list_add(&iface->iface_list_entry, &iface_list);
	return iface;
}

int pingu_iface_init(struct ev_loop *loop, struct list_head *host_list)
{
	struct pingu_host *host;
	struct pingu_iface *iface;
	list_for_each_entry(host, host_list, host_list_entry) {
		iface = pingu_iface_find_or_create(loop, host->interface);
		if (iface == NULL)
			return -1;
		host->iface = iface;
	}
	return 0;
}