/*
 *   Copyright (C) 2010 John Crispin <blogic@openwrt.org>
 *   Copyright (C) 2010 Steven Barth <steven@midlink.org>
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 *
 */

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <poll.h>
#include <string.h>
#include <time.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/epoll.h>

#include <libubus.h>
#include "uloop.h"
#include "ulog.h"

struct uloop_sock
{
	int sock;
	void *priv;
	_uloop_sock_handler cb;
};

static int epoll_fd = 0;
static int uloop_loop = 1;
static struct ubus_ctx *uloop_ubus = 0;

void uloop_init(void)
{
	epoll_fd = epoll_create(32);
	fcntl(epoll_fd, F_SETFD, fcntl(epoll_fd, F_GETFD) | FD_CLOEXEC);
}

static void uloop_ubus_cb(struct uloop_sock *u)
{
	ubus_recv(uloop_ubus);
}

struct uloop_sock* uloop_sock_add(int sock, void *priv, _uloop_sock_handler cb)
{
	struct epoll_event ev;
	struct uloop_sock *u = malloc(sizeof(struct uloop_sock));
	u->sock = sock;
	u->priv = priv;
	u->cb = cb;
	memset(&ev, 0, sizeof(struct epoll_event));
	ev.events = EPOLLIN | EPOLLET | EPOLLRDHUP;
	ev.data.fd = sock;
	ev.data.ptr = u;
	epoll_ctl(epoll_fd, EPOLL_CTL_ADD, sock, &ev);
	return u;
}

void uloop_ubus_add(struct ubus_ctx *ctx)
{
	if(!uloop_ubus)
		uloop_ubus = ctx;
}

void uloop_sock_delete(struct uloop_sock *u)
{
	if(u->priv != uloop_ubus)
		free(u->priv);
	free(u);
}

static void uloop_handler_INT(int signo)
{
	LOG("away we go\n");
	uloop_loop = 0;
}

static void uloop_setup_signals(void)
{
	struct sigaction s1, s2;
	memset(&s1, 0, sizeof(struct sigaction));
	memset(&s2, 0, sizeof(struct sigaction));
	s1.sa_handler = uloop_handler_INT;
	s1.sa_flags = 0;
	sigaction(SIGINT, &s1, NULL);
	s2.sa_handler = uloop_handler_INT;
	s2.sa_flags = 0;
	sigaction(SIGTERM, &s2, NULL);
}

int uloop(void (*cb)(void), int timeout)
{
	#define MAX_EVENTS	10
	struct uloop_sock *ubus_sock = 0;
	struct epoll_event events[MAX_EVENTS];
	int nfds, n;
	time_t t = time(0);
	uloop_loop = 1;
	uloop_setup_signals();
	while(uloop_loop)
	{
		if(uloop_ubus)
			if(ubus_connect(uloop_ubus) > 0)
			{
				int ubus_fd = ubus_get_sock(uloop_ubus);
				fcntl(ubus_fd, F_SETFD, fcntl(ubus_fd, F_GETFD) | FD_CLOEXEC);
				ubus_sock = uloop_sock_add(ubus_fd, uloop_ubus, uloop_ubus_cb);
			}
		nfds = epoll_wait(epoll_fd, events, MAX_EVENTS, 1000);
		for(n = 0; n < nfds; ++n)
		{
			struct uloop_sock *u = (struct uloop_sock*)events[n].data.ptr;
			if(events[n].events & EPOLLRDHUP)
			{
				epoll_ctl(epoll_fd, EPOLL_CTL_DEL, u->sock, 0);
				uloop_sock_delete(u);
			} else if(events[n].events & EPOLLIN)
			{
				if(u->cb)
					u->cb(u);
			}
		}
		if(cb)
		{
			if(difftime(time(0), t) < timeout)
				continue;
			t = time(0);
			cb();
		}
	}
	if(ubus_sock)
		uloop_sock_delete(ubus_sock);
	return 0;
}