#include <mach/mach_types.h>
#include <mach/thread_act.h>
#include <mach/mach_init.h>
#include <mach/mach_error.h>
#include "global.h"
#include "Backtrace.h"

#include <cmath>
#include <cstdint>
#include <string>

bool SuspendThread( uint64_t threadHandle )
{
	return !thread_suspend( thread_act_t(threadHandle) );
}

bool ResumeThread( uint64_t threadHandle )
{
	return !thread_resume( thread_act_t(threadHandle) );
}

uint64_t GetCurrentThreadId()
{
	return mach_thread_self();
}

bool GetThreadBacktraceContext( uint64_t iID, BacktraceContext *ctx )
{
	/* Can't GetThreadBacktraceContext the current thread. */
	ASSERT( iID != GetCurrentThreadId() );
	SuspendThread( iID );

	thread_act_t thread = thread_act_t( iID );

#if defined(__i386__)
	i386_thread_state_t state;
	mach_msg_type_number_t count = i386_THREAD_STATE_COUNT;

	if( thread_get_state(thread, i386_THREAD_STATE, thread_state_t(&state), &count) )
		return false;
	ctx->ip = (void *)state.__eip;
	ctx->bp = (void *)state.__ebp;
	ctx->sp = (void *)state.__esp;
	return true;
#elif defined(__x86_64__)
	x86_thread_state64_t state;
	mach_msg_type_number_t count = x86_THREAD_STATE64_COUNT;

	if (thread_get_state(thread, x86_THREAD_STATE64, thread_state_t(&state), &count))
	{
		return false;
	}

	ctx->ip = (void *)state.__rip;
	ctx->bp = (void *)state.__rbp;
	ctx->sp = (void *)state.__rsp;
	return true;
#else
	return false;
#endif
}

std::string SetThreadPrecedence( float prec )
{
	// Real values are between 0 and 63.
	DEBUG_ASSERT( 0.0f <= prec && prec <= 1.0f );
	thread_precedence_policy po = { integer_t( std::lrint(prec * 63) ) };
	kern_return_t ret = thread_policy_set( mach_thread_self(), THREAD_PRECEDENCE_POLICY,
					       (thread_policy_t)&po, THREAD_PRECEDENCE_POLICY_COUNT );

	if( ret != KERN_SUCCESS )
		return mach_error_string( ret );
	return "";
}

/*
 * (c) 2004-2006 Steve Checkoway
 * All rights reserved.
 *
 * 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, and/or sell copies of the Software, and to permit persons to
 * whom the Software is furnished to do so, provided that the above
 * copyright notice(s) and this permission notice appear in all copies of
 * the Software and that both the above copyright notice(s) and this
 * permission notice appear in supporting documentation.
 *
 * 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 OF
 * THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS
 * INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT
 * OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
 * OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
 * OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */