#include "utilities/FixedIntervalRunLoop.h"

#include <stdlib.h>

#include "shell/Shell.h"

FixedIntervalRunLoop * FixedIntervalRunLoop_create(double stepInterval, void (* stepCallback)(void *), void * stepContext) {
	FixedIntervalRunLoop * self;
	
	self = malloc(sizeof(FixedIntervalRunLoop));
	FixedIntervalRunLoop_init(self, stepInterval, stepCallback, stepContext);
	return self;
}

void FixedIntervalRunLoop_init(FixedIntervalRunLoop * self, double stepInterval, void (* stepCallback)(void *), void * stepContext) {
	self->stepInterval = stepInterval;
	self->stepCallback = stepCallback;
	self->stepContext = stepContext;
	self->lastTime = Shell_getCurrentTime();
	self->slop = 0.0;
	
	self->dispose = FixedIntervalRunLoop_dispose;
	self->run = FixedIntervalRunLoop_run;
}

void FixedIntervalRunLoop_dispose(void * selfPtr) {
	free(selfPtr);
}

void FixedIntervalRunLoop_run(void * selfPtr) {
	FixedIntervalRunLoop * self = selfPtr;
	double currentTime, interval;
	
	currentTime = Shell_getCurrentTime();
	interval = (currentTime - self->lastTime) + self->slop;
	
	while (interval > self->stepInterval) {
		self->stepCallback(self->stepContext);
		interval -= self->stepInterval;
	}
	self->slop = interval;
	self->lastTime = currentTime;
}