/*
 * This file is subject to the terms of the GFX License. If a copy of
 * the license was not distributed with this file, you can obtain one at:
 *
 *              http://ugfx.org/license.html
 */

/**
 * @file    src/gos/osx.c
 * @brief   GOS ChibiOS Operating System support.
 */
#include "gfx.h"

#if GFX_USE_OS_OSX

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>
#include <time.h>
#include <sys/time.h>
#include <sched.h>
#include <mach/clock.h>
#include <mach/mach.h>

static gfxMutex		SystemMutex;


void get_ticks(mach_timespec_t *mts){
	clock_serv_t cclock;
	//mach_timespec_t mts;

	host_get_clock_service(mach_host_self(), SYSTEM_CLOCK, &cclock);
	clock_get_time(cclock, mts);
	mach_port_deallocate(mach_task_self(), cclock);

	
}

void _gosInit(void) {
	gfxMutexInit(&SystemMutex);
}

void gfxSystemLock(void) {
	gfxMutexEnter(&SystemMutex);
}

void gfxSystemUnlock(void) {
	gfxMutexExit(&SystemMutex);
}

void gfxHalt(const char *msg) {
	if (msg)
		fprintf(stderr, "%s\n", msg);
	exit(1);
}

void gfxSleepMilliseconds(delaytime_t ms) {
	struct timespec	ts;

	switch(ms) {
	case TIME_IMMEDIATE:	gfxYield();			return;
	case TIME_INFINITE:		while(1) sleep(60);			return;
	default:
		ts.tv_sec = ms / 1000;
		ts.tv_nsec = (ms % 1000) * 1000;
		nanosleep(&ts, 0);
		return;
	}
}

void gfxSleepMicroseconds(delaytime_t ms) {
	struct timespec	ts;

	switch(ms) {
	case TIME_IMMEDIATE:	gfxYield();			return;
	case TIME_INFINITE:		while(1) sleep(60);			return;
	default:
		ts.tv_sec = ms / 1000000;
		ts.tv_nsec = ms % 1000000;
		nanosleep(&ts, 0);
		return;
	}
}

systemticks_t gfxSystemTicks(void) {
	//struct timespec	ts;
	//clock_gettime(CLOCK_MONOTONIC, &ts);
	
	mach_timespec_t ts;
	get_ticks(&ts);
	
	
	return ts.tv_sec * 1000UL + ts.tv_nsec / 1000UL;
}

gfxThreadHandle gfxThreadCreate(void *stackarea, size_t stacksz, threadpriority_t prio, DECLARE_THREAD_FUNCTION((*fn),p), void *param) {
	gfxThreadHandle		th;

	// Implementing priority with pthreads is a rats nest that is also pthreads implementation dependent.
	//	Only some pthreads schedulers support it, some implementations use the operating system process priority mechanisms.
	//	Even those that do support it can have different ranges of priority and "normal" priority is an undefined concept.
	//	Across different UNIX style operating systems things can be very different (let alone OS's such as Windows).
	//	Even just Linux changes the way priority works with different kernel schedulers and across kernel versions.
	//	For these reasons we ignore the priority.

	if (pthread_create(&th, 0, fn, param))
		return 0;
	return th;
}

threadreturn_t gfxThreadWait(gfxThreadHandle thread) {
	threadreturn_t	retval;

	if (pthread_join(thread, &retval))
		return 0;
	return retval;
}

void gfxSemInit(gfxSem *pSem, semcount_t val, semcount_t limit) {
	pthread_mutex_init(&pSem->mtx, 0);
	pthread_cond_init(&pSem->cond, 0);
	pthread_mutex_lock(&pSem->mtx);
	pSem->cnt = val;
	pSem->max = limit;
	pthread_mutex_unlock(&pSem->mtx);
}

void gfxSemDestroy(gfxSem *pSem) {
	pthread_mutex_destroy(&pSem->mtx);
	pthread_cond_destroy(&pSem->cond);
}

bool_t gfxSemWait(gfxSem *pSem, delaytime_t ms) {
	pthread_mutex_lock(&pSem->mtx);
	switch (ms) {
	case TIME_INFINITE:
		while (!pSem->cnt)
			pthread_cond_wait(&pSem->cond, &pSem->mtx);
		break;
	case TIME_IMMEDIATE:
		if (!pSem->cnt) {
			pthread_mutex_unlock(&pSem->mtx);
			return FALSE;
		}
		break;
	default:
		{
			struct timeval now;
			struct timespec	tm;

			gettimeofday(&now, NULL);
			tm.tv_sec = now.tv_sec + ms / 1000;
			tm.tv_nsec = (now.tv_usec + ms % 1000) * 1000;
			while (!pSem->cnt) {
				if (pthread_cond_timedwait(&pSem->cond, &pSem->mtx, &tm) == ETIMEDOUT) {
					pthread_mutex_unlock(&pSem->mtx);
					return FALSE;
				}
			}
		}
		break;
	}
	pSem->cnt--;
	pthread_mutex_unlock(&pSem->mtx);
	return TRUE;
}

void gfxSemSignal(gfxSem *pSem) {
	pthread_mutex_lock(&pSem->mtx);
	if (pSem->cnt < pSem->max) {
		pSem->cnt++;
		pthread_cond_signal(&pSem->cond);
	}
	pthread_mutex_unlock(&pSem->mtx);
}

semcount_t gfxSemCounter(gfxSem *pSem) {
	semcount_t	res;

	// The locking is really only required if obtaining the count is a divisible operation
	//	which it might be on a 8/16 bit processor with a 32 bit semaphore count.
	pthread_mutex_lock(&pSem->mtx);
	res = pSem->cnt;
	pthread_mutex_unlock(&pSem->mtx);
	return res;
}

#endif /* GFX_USE_OS_OSX */
/** @} */

