// Timer.cc for Blackbox - An X11 Window Manager
// Copyright (c) 1997 - 2000 Brad Hughes (bhughes@tcac.net)
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.

#include "Timer.hh"

//use GNU extensions
#ifndef	_GNU_SOURCE
#define _GNU_SOURCE
#endif // _GNU_SOURCE

#ifdef	HAVE_CONFIG_H
#include "../config.h"
#endif // HAVE_CONFIG_H

#include <sys/types.h>
#include <unistd.h>
#include <cassert>

//static var
BTimer::TimerList BTimer::m_timerlist;

BTimer::BTimer(TimeoutHandler *h):
m_handler(h),
m_timing(false),
m_once(false) {
}


BTimer::~BTimer() {
	if (isTiming()) stop();
}


void BTimer::setTimeout(long t) {
	m_timeout.tv_sec = t / 1000;
	m_timeout.tv_usec = t;
	m_timeout.tv_usec -= (m_timeout.tv_sec * 1000);
	m_timeout.tv_usec *= 1000;
}


void BTimer::setTimeout(timeval t) {
	m_timeout.tv_sec = t.tv_sec;
	m_timeout.tv_usec = t.tv_usec;
}


void BTimer::start() {
	gettimeofday(&m_start, 0);

	if (! m_timing) {
		m_timing = true;
		addTimer(this); //add us to the list
	}
}


void BTimer::stop() {
	m_timing = false;
	removeTimer(this); //remove us from the list
}


void BTimer::fireTimeout() {
	if (m_handler) m_handler->timeout();
}

void BTimer::updateTimers(int fd) {
	fd_set rfds;
	timeval now, tm, *timeout = 0;

	FD_ZERO(&rfds);
	FD_SET(fd, &rfds);

	if (m_timerlist.size() > 0) {
		gettimeofday(&now, 0);

		tm.tv_sec = tm.tv_usec = 0l;

		BTimer *timer = m_timerlist.front();

		tm.tv_sec = timer->getStartTime().tv_sec +
			timer->getTimeout().tv_sec - now.tv_sec;
		tm.tv_usec = timer->getStartTime().tv_usec +
			timer->getTimeout().tv_usec - now.tv_usec;

		while (tm.tv_usec >= 1000000) {
			tm.tv_sec++;
			tm.tv_usec -= 1000000;
		}

		while (tm.tv_usec < 0) {
			if (tm.tv_sec > 0) {
				tm.tv_sec--;
				tm.tv_usec += 1000000;
			} else {
				tm.tv_usec = 0;
				break;
			}
		}

		timeout = &tm;
	}

	select(fd + 1, &rfds, 0, 0, timeout);

	// check for timer timeout
	gettimeofday(&now, 0);

	TimerList::iterator it = m_timerlist.begin();
	//must check end ...the timer might remove
	//it self from the list (should be fixed in the future)
	for(; it != m_timerlist.end(); ++it) {
		//This is to make sure we don't get an invalid iterator
		//when we do fireTimeout
		BTimer &t = *(*it);
		tm.tv_sec = t.getStartTime().tv_sec +
		t.getTimeout().tv_sec;
		tm.tv_usec = t.getStartTime().tv_usec +
		t.getTimeout().tv_usec;

		if ((now.tv_sec < tm.tv_sec) ||
			(now.tv_sec == tm.tv_sec && now.tv_usec < tm.tv_usec))
			break;

		t.fireTimeout();
		// restart the current timer so that the start time is updated
		if (! t.doOnce())
			t.start();
		else {
			t.stop();			
			it--;
		}					
	}
}

void BTimer::addTimer(BTimer *timer) {
	assert(timer);

	TimerList::iterator it = m_timerlist.begin();
	TimerList::iterator it_end = m_timerlist.end();
	int index = 0;
	for (; it != it_end; ++it, ++index) {
		if (((*it)->getTimeout().tv_sec > timer->getTimeout().tv_sec) ||
				(((*it)->getTimeout().tv_sec == timer->getTimeout().tv_sec) &&
				((*it)->getTimeout().tv_usec >= timer->getTimeout().tv_usec))) {
			break;
		}
	}
	m_timerlist.insert(it, timer); 

}

void BTimer::removeTimer(BTimer *timer) {
	assert(timer);
	m_timerlist.remove(timer);
}