//-----------------------------------------------------------------------------
// Copyright (C) 2010 iZsh <izsh at fail0verflow.com>
//
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// utilities requiring Posix library functions
//-----------------------------------------------------------------------------

#if !defined(_WIN32)
#define _POSIX_C_SOURCE	199309L			// need nanosleep()
#else
#include <windows.h>
#endif

#include "util_posix.h"
#include <stdint.h>
#include <time.h>


// Timer functions
#if !defined (_WIN32)
#include <errno.h>

static void nsleep(uint64_t n) {
	struct timespec timeout;
	timeout.tv_sec = n/1000000000;
	timeout.tv_nsec = n%1000000000;
	while (nanosleep(&timeout, &timeout) && errno == EINTR);
}

void msleep(uint32_t n) {
	nsleep(1000000 * (uint64_t)n);
}
#endif // _WIN32

#ifdef __APPLE__

#ifndef CLOCK_MONOTONIC
	#define CLOCK_MONOTONIC (1)
#endif
#ifndef CLOCK_REALTIME	
	#define CLOCK_REALTIME (2)
#endif

	#include <sys/time.h>
	#include <mach/clock.h>
	#include <mach/mach.h>
	#include <mach/mach_time.h>

	/* clock_gettime is not implemented on OSX prior to 10.12 */
	int _civet_clock_gettime(int clk_id, struct timespec *t);

	int _civet_clock_gettime(int clk_id, struct timespec *t)
	{
		memset(t, 0, sizeof(*t));
		if (clk_id == CLOCK_REALTIME) {
			struct timeval now;
			int rv = gettimeofday(&now, NULL);
			if (rv) {
				return rv;
			}
			t->tv_sec = now.tv_sec;
			t->tv_nsec = now.tv_usec * 1000;
			return 0;

		} else if (clk_id == CLOCK_MONOTONIC) {
			static uint64_t clock_start_time = 0;
			static mach_timebase_info_data_t timebase_info = {0, 0};

			uint64_t now = mach_absolute_time();

			if (clock_start_time == 0) {
				
				mach_timebase_info(&timebase_info);
				clock_start_time = now;
			}

			now = (uint64_t)((double)(now - clock_start_time)
			                 * (double)timebase_info.numer
			                 / (double)timebase_info.denom);

			t->tv_sec = now / 1000000000;
			t->tv_nsec = now % 1000000000;
			return 0;
		}
		return -1; // EINVAL - Clock ID is unknown
	}

	/* if clock_gettime is declared, then __CLOCK_AVAILABILITY will be defined */
	#ifdef __CLOCK_AVAILABILITY
		/* If we compiled with Mac OSX 10.12 or later, then clock_gettime will be declared
		 * but it may be NULL at runtime. So we need to check before using it. */
		int _civet_safe_clock_gettime(int clk_id, struct timespec *t);

		int _civet_safe_clock_gettime(int clk_id, struct timespec *t) {
			if( clock_gettime ) {
				return clock_gettime(clk_id, t);
			}
			return _civet_clock_gettime(clk_id, t);
		}
		#define clock_gettime _civet_safe_clock_gettime
	#else
		#define clock_gettime _civet_clock_gettime
	#endif

#endif


// a milliseconds timer for performance measurement
uint64_t msclock(void) {
#if defined(_WIN32)
	#include <sys/types.h>

	// WORKAROUND FOR MinGW (some versions - use if normal code does not compile)
	// It has no _ftime_s and needs explicit inclusion of timeb.h
	#include <sys/timeb.h>
	struct _timeb t;
	_ftime(&t);
	return 1000 * (uint64_t)t.time + t.millitm;

// NORMAL CODE (use _ftime_s)
	//struct _timeb t;
	//if (_ftime_s(&t)) {
	//	return 0;
	//} else {
	//	return 1000 * t.time + t.millitm;
	//}
#else
	struct timespec t;
	clock_gettime(CLOCK_MONOTONIC, &t);
	return ( 1000 * (uint64_t)t.tv_sec + t.tv_nsec / 1000000);
#endif
}