#include <sys/select.h>
#include <sys/epoll.h>
#include <errno.h>

#include "selectops.h"
#include "babd.h"
#include "link.h"

static int bab_maxfd = -1;

static fd_set rfds;
static fd_set wfds;

int use_epoll = 1;
int epoll_fd = -1;

inline void SelectEventHandler::touch_fd(int fd)
{
	if (-1 == fd_used)
		fd_used = fd;
	else if (fd_used != fd)
		scan_all = 1;

	if (fd > bab_maxfd)
		bab_maxfd = fd;
}

static int select_poll_core(struct timeval *tv)
{
	int maxfd = 0, i;

	for (i=0; i<=bab_maxfd; i++) {
		if (selectObjs[0][i])
			FD_SET(i, &rfds);

		if (selectObjs[1][i])
			FD_SET(i, &wfds);
	}

	maxfd = i;

	maxfd = select(maxfd, &rfds, &wfds, NULL, tv);
	if (maxfd < 0) {
		if (EINTR == errno)
			return 1;
		perror("select");
		return 1;
	}
	
	for (i=0; i<=bab_maxfd; i++) {
		if (FD_ISSET(i, &rfds) || FD_ISSET(i, &wfds))
			maxfd--;

		if (FD_ISSET(i, &rfds) && selectObjs[0][i])
			selectObjs[0][i]->SelectEvent(i, SEL_READ);

		if (FD_ISSET(i, &wfds) && selectObjs[1][i])
			selectObjs[1][i]->SelectEvent(i, SEL_WRITE);
	}

	return 0;
}

static int epoll_poll_core(struct timeval *tv)
{
#define MAX_EPOLL_EVENTS	1000
	struct epoll_event events[MAX_EPOLL_EVENTS];
	int timeout;
	int nr;

	if (tv->tv_sec > 65)
		timeout = 65000;
	else
		timeout = tv->tv_sec * 1000 + (tv->tv_usec / 1000);

	nr = epoll_wait(epoll_fd, events, MAX_EPOLL_EVENTS, timeout);
	if (nr == -1) {
		if (errno == EINTR)
			return 1;
		perror("epoll_wait");
		return 1;
	}

	for (int i=0; i<nr; i++) {
		struct epoll_event *ev = &events[i];
		if ((ev->events & (EPOLLIN | EPOLLERR)) && selectObjs[0][ev->data.fd])
			selectObjs[0][ev->data.fd]->SelectEvent(ev->data.fd, SEL_READ);
		if ((ev->events & EPOLLOUT) && selectObjs[1][ev->data.fd])
			selectObjs[1][ev->data.fd]->SelectEvent(ev->data.fd, SEL_WRITE);
	}
	return 0;
}

void bab_poll(void)
{
	struct timeval tv;

	killIfaces();
	do_hangups();
	killIfaces();
	FD_ZERO(&rfds);
	FD_ZERO(&wfds);

again:
	tv = timer_getdelay();
	if (use_epoll) {
		if (epoll_poll_core(&tv))
			goto again;
	} else {
		if (select_poll_core(&tv))
			goto again;
	}

	killIfaces();
	do_hangups();
	killIfaces();

	timer_run();

	killIfaces();
	do_hangups();
}

SelectEventHandler::SelectEventHandler()
{
	scan_all = 0;
	fd_used = -1;
}


SelectEventHandler::~SelectEventHandler()
{
	int i;
	if (scan_all) {
		for (i=0; i<BAB_OPEN_MAX; i++) {
			if (selectObjs[0][i] == this)
				selectObjs[0][i] = NULL;
			if (selectObjs[1][i] == this)
				selectObjs[1][i] = NULL;
		}
	} else {
		if (fd_used < 0)
			return;

		if (selectObjs[0][fd_used] == this)
			selectObjs[0][fd_used] = NULL;
		if (selectObjs[1][fd_used] == this)
			selectObjs[1][fd_used] = NULL;
	}
	fd_used = -1;
}

void SelectEventHandler::SelectAddEvent(int fd, SelectEventType event)
{
	int had_old = (selectObjs[0][fd] || selectObjs[1][fd]);
	if (!fd || fd < 0)
		*(char *)0 = 0;

	if (event & SEL_READ)
		selectObjs[0][fd] = this;
	if (event & SEL_WRITE)
		selectObjs[1][fd] = this;

	touch_fd(fd);

	if (use_epoll) {
		struct epoll_event ev;
		memset(&ev, 0, sizeof ev);
		ev.data.fd = fd;
		if (selectObjs[0][fd])
			ev.events |= EPOLLIN;
		if (selectObjs[1][fd])
			ev.events |= EPOLLOUT;
		if (had_old) {
			if (epoll_ctl(epoll_fd, EPOLL_CTL_MOD, fd, &ev) == -1) {
				perror("AddEvent: epoll_ctl: MOD");
				*(char *)0 = 0;
			}
		} else if (epoll_ctl(epoll_fd, EPOLL_CTL_ADD, fd, &ev) == -1) {
			perror("AddEvent: epoll_ctl: ADD");
			*(char *)0 = 0;
		}
	}
}

void SelectEventHandler::SelectSetEvents(int fd, SelectEventType event)
{
	struct epoll_event ev;
	int had;
	if (!fd)
		*(char *)0 = 0;

	had = (selectObjs[0][fd] || selectObjs[1][fd]);

	memset(&ev, 0, sizeof ev);
	ev.data.fd = fd;

	selectObjs[0][fd] = (event & SEL_READ) ? this : 0;
	selectObjs[1][fd] = (event & SEL_WRITE) ? this : 0;

	if (selectObjs[0][fd])
		ev.events |= EPOLLIN;
	if (selectObjs[1][fd])
		ev.events |= EPOLLOUT;

	if ((event & (SEL_READ | SEL_WRITE))) {
		if (fd > bab_maxfd)
			touch_fd(fd);
		if (use_epoll) {
			int op = had ? EPOLL_CTL_MOD : EPOLL_CTL_ADD;
			if (-1 == epoll_ctl(epoll_fd, op, fd, &ev)) {
				perror("Set: epoll_ctl: MOD");
				*(char *)0 = 0;
			}
		}
		return;
	}

	if (use_epoll && had && (event == SEL_NONE)) {
		if (-1 == epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fd, &ev)) {
			perror("Set(none): epoll_ctl: DEL");
			fprintf(stderr, "pid = %d\n", (int)getpid());
			*(char *)0 = 0;
		}
	}

	if (fd == bab_maxfd && !selectObjs[0][fd] && !selectObjs[1][fd]) {
		int i;
		for (i=bab_maxfd-1; i>-1; i--)
			if (selectObjs[0][i] || selectObjs[1][i])
				break;
		bab_maxfd = i;
	}
}

void SelectEventHandler::SelectRemoveEvent(int fd, SelectEventType event)
{
	int removed_read = 0, removed_write = 0;

	if (event & SEL_READ) {
		if (selectObjs[0][fd])
			removed_read = 1;
		selectObjs[0][fd] = 0;
	}
	if (event & SEL_WRITE) {
		if (selectObjs[1][fd])
			removed_write = 1;
		selectObjs[1][fd] = 0;
	}

	if (fd == bab_maxfd && !selectObjs[0][fd] && !selectObjs[1][fd]) {
		int i;
		for (i=bab_maxfd-1; i>-1; i--)
			if (selectObjs[0][i] || selectObjs[1][i])
				break;
		bab_maxfd = i;
	}

	if (use_epoll) {
		struct epoll_event ev;
		memset(&ev, 0, sizeof ev);
		ev.data.fd = fd;
		if (selectObjs[0][fd])
			ev.events |= EPOLLIN;
		if (selectObjs[1][fd])
			ev.events |= EPOLLOUT;
		if (!ev.events) {
			if (removed_read || removed_write) {
				if (-1 == epoll_ctl(epoll_fd, EPOLL_CTL_DEL, fd, &ev)) {
					perror("Remove: epoll_ctl: DEL");
					*(char *)0 = 0;
				}
			}
		} else {
			if (-1 == epoll_ctl(epoll_fd, EPOLL_CTL_MOD, fd, &ev)) {
				perror("Remove: epoll_ctl: MOD");
				*(char *)0 = 0;
			}
		}
	}
}


void selectops_epoll_init(void)
{
	epoll_fd = epoll_create(256);
	if (epoll_fd == -1) {
		perror("epoll_create");
		use_epoll = 0;
		return;
	}
	use_epoll = 1;
}