#include <inttypes.h>
#include <sys/timerfd.h>
#include <sys/socket.h>
#include <netinet/ip.h>
#include <arpa/inet.h>
#include <string.h>

#include "main.h"
#include "uring.h"
#include "config.h"
#include "announce.h"
#include "server.h"

struct announce {
	uint64_t value;
	struct uring_task task;
	struct uring_task mcast_task;
};

static void
mcast_free(struct uring_task *task)
{
	struct announce *aev = container_of(task, struct announce, mcast_task);

	debug(DBG_ANN, "task %p, aev %p\n", task, aev);
}

static void
mcast_sent(struct cfg *cfg, struct uring_task *task, int res)
{
	if (res < 0)
		error("failure %i\n", res);
	else
		debug(DBG_ANN, "result %i\n", res);
}

static void
mcast_send(struct cfg *cfg, struct announce *aev, struct server *server)
{
	int len;

	if (!server || !server->pretty_name || server->announce_port < 1)
		return;

	len = snprintf(server->mcast_buf.buf, sizeof(server->mcast_buf.buf),
		       "[MOTD]%s[/MOTD][AD]%" PRIu16 "[/AD]",
		       server->pretty_name, server->announce_port);

	if (len < 1 || len >= sizeof(server->mcast_buf.buf)) {
		error("snprintf returned %i\n", len);
		return;
	}

	server->mcast_buf.len = len;
	uring_task_set_buf(&aev->mcast_task, &server->mcast_buf);
	uring_tbuf_sendmsg(cfg, &aev->mcast_task, mcast_sent);
}

static void
mcast_send_all(struct cfg *cfg, struct announce *aev)
{
	struct server *server;

	list_for_each_entry(server, &cfg->servers, list) {
		verbose("Announcing server: %s\n", server->name);
		mcast_send(cfg, aev, server);
	}
}

static void
announce_cb(struct cfg *cfg, struct uring_task *task, int res)
{
	struct announce *aev = container_of(task, struct announce, task);

	if (task->dead) {
		debug(DBG_ANN, "task is dead\n");
		return;
	}

	if (res != sizeof(aev->value))
		perrordie("timerfd_read");

	debug(DBG_ANN, "timerfd value %" PRIu64 "\n", aev->value);
	mcast_send_all(cfg, aev);
	uring_read(cfg, &aev->task, &aev->value, sizeof(aev->value), announce_cb);
}

static void
announce_free(struct uring_task *task)
{
	struct announce *aev = container_of(task, struct announce, task);

	debug(DBG_ANN, "task %p, aev 0x%p\n", task, aev);
	xfree(aev);
}

void
announce_refdump(struct announce *aev)
{
	if (!aev)
		return;

	uring_task_refdump(&aev->task);
	uring_task_refdump(&aev->mcast_task);
}

void
announce_delete(struct cfg *cfg)
{
	if (!cfg->aev) {
		error("missing parameters\n");
		return;
	}

	debug(DBG_ANN, "closing fd %i\n", cfg->aev->task.fd);
	uring_task_destroy(cfg, &cfg->aev->mcast_task);
	uring_task_destroy(cfg, &cfg->aev->task);
	cfg->aev = NULL;
}

void
announce_stop(struct announce *aev)
{
	struct itimerspec tspec = {
		.it_interval = {
			.tv_sec  = 0,
			.tv_nsec = 0
		},
		.it_value = {
			.tv_sec  = 0,
			.tv_nsec = 0
		}
	};

	if (timerfd_settime(aev->task.fd, 0, &tspec, NULL) != 0)
		perrordie("timerfd_settime");
}

void
announce_start(struct announce *aev)
{
	struct itimerspec tspec = {
		.it_interval = {
			.tv_sec  = 3,
			.tv_nsec = 0
		},
		.it_value = {
			.tv_sec  = 3,
			.tv_nsec = 0
		}
	};

	if (timerfd_settime(aev->task.fd, 0, &tspec, NULL) != 0)
		perrordie("timerfd_settime");
}

void
announce_init(struct cfg *cfg)
{
	struct announce *aev;
	int afd;
	int sfd;
 
	aev = zmalloc(sizeof(*aev));
	if (!aev)
		perrordie("malloc");

	afd = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC);
	if (afd < 0)
		perrordie("timerfd_create");

	sfd = socket(AF_INET, SOCK_DGRAM | SOCK_CLOEXEC, 0);
	if (sfd < 0)
		perrordie("socket");

	uring_task_init(&aev->task, "aev", uring_parent(cfg), announce_free);
	uring_task_set_fd(&aev->task, afd);

	uring_task_init(&aev->mcast_task, "aev_mcast", &aev->task, mcast_free);
	uring_task_set_fd(&aev->mcast_task, sfd);
	aev->mcast_task.saddr.in4.sin_family = AF_INET;
	aev->mcast_task.saddr.in4.sin_addr.s_addr = inet_addr("224.0.2.60");
	aev->mcast_task.saddr.in4.sin_port = htons(4445);
	aev->mcast_task.saddr.addrlen = sizeof(aev->mcast_task.saddr.in4);
	saddr_set_str(&aev->mcast_task.saddr);

	cfg->aev = aev;
	uring_read(cfg, &aev->task, &aev->value, sizeof(aev->value), announce_cb);
}