/**
 * @file    rpm_calculator.cpp
 * @brief   RPM calculator
 *
 * Here we listen to position sensor events in order to figure our if engine is currently running or not.
 * Actual getRpm() is calculated once per crankshaft revolution, based on the amount of time passed
 * since the start of previous shaft revolution.
 *
 * We also have 'instant RPM' logic separate from this 'cycle RPM' logic. Open question is why do we not use
 * instant RPM instead of cycle RPM more often.
 *
 * @date Jan 1, 2013
 * @author Andrey Belomutskiy, (c) 2012-2019
 */

#include "globalaccess.h"
#include "os_access.h"
#include "engine.h"
#include "rpm_calculator.h"

#include "trigger_central.h"
#include "engine_configuration.h"
#include "engine_math.h"
#include "perf_trace.h"

#if EFI_PROD_CODE
#include "os_util.h"
#endif /* EFI_PROD_CODE */

#if EFI_SENSOR_CHART
#include "sensor_chart.h"
#endif



#if EFI_ENGINE_SNIFFER
#include "engine_sniffer.h"
extern WaveChart waveChart;
#endif /* EFI_ENGINE_SNIFFER */

// See RpmCalculator::checkIfSpinning()
#ifndef NO_RPM_EVENTS_TIMEOUT_SECS
#define NO_RPM_EVENTS_TIMEOUT_SECS 2
#endif /* NO_RPM_EVENTS_TIMEOUT_SECS */

float RpmCalculator::getRpmAcceleration() const {
	return 1.0 * previousRpmValue / rpmValue;
}

bool RpmCalculator::isStopped(DECLARE_ENGINE_PARAMETER_SIGNATURE) const {
	// Spinning-up with zero RPM means that the engine is not ready yet, and is treated as 'stopped'.
	return state == STOPPED || (state == SPINNING_UP && rpmValue == 0);
}

bool RpmCalculator::isCranking(DECLARE_ENGINE_PARAMETER_SIGNATURE) const {
	// Spinning-up with non-zero RPM is suitable for all engine math, as good as cranking
	return state == CRANKING || (state == SPINNING_UP && rpmValue > 0);
}

bool RpmCalculator::isSpinningUp(DECLARE_ENGINE_PARAMETER_SIGNATURE) const {
	return state == SPINNING_UP;
}

uint32_t RpmCalculator::getRevolutionCounterSinceStart(void) const {
	return revolutionCounterSinceStart;
}

/**
 * @return -1 in case of isNoisySignal(), current RPM otherwise
 * See NOISY_RPM
 */
// todo: migrate to float return result or add a float version? this would have with calculations
int RpmCalculator::getRpm(DECLARE_ENGINE_PARAMETER_SIGNATURE) const {
#if !EFI_PROD_CODE
	if (mockRpm != MOCK_UNDEFINED) {
		return mockRpm;
	}
#endif /* EFI_PROD_CODE */
	return rpmValue;
}

#if EFI_SHAFT_POSITION_INPUT

EXTERN_ENGINE
;

extern bool hasFirmwareErrorFlag;

static Logging * logger;

RpmCalculator::RpmCalculator() {
#if !EFI_PROD_CODE
	mockRpm = MOCK_UNDEFINED;
#endif /* EFI_PROD_CODE */
	// todo: reuse assignRpmValue() method which needs PASS_ENGINE_PARAMETER_SUFFIX
	// which we cannot provide inside this parameter-less constructor. need a solution for this minor mess

	// we need this initial to have not_running at first invocation
	lastRpmEventTimeNt = (efitick_t) -10 * US2NT(US_PER_SECOND_LL);
}

/**
 * @return true if there was a full shaft revolution within the last second
 */
bool RpmCalculator::isRunning(DECLARE_ENGINE_PARAMETER_SIGNATURE) const {
	return state == RUNNING;
}

/**
 * @return true if engine is spinning (cranking or running)
 */
bool RpmCalculator::checkIfSpinning(efitick_t nowNt DECLARE_ENGINE_PARAMETER_SUFFIX) const {
	if (ENGINE(needToStopEngine(nowNt))) {
		return false;
	}

	/**
	 * note that the result of this subtraction could be negative, that would happen if
	 * we have a trigger event between the time we've invoked 'getTimeNow' and here
	 */
	bool noRpmEventsForTooLong = nowNt - lastRpmEventTimeNt >= US2NT(NO_RPM_EVENTS_TIMEOUT_SECS * US_PER_SECOND_LL); // Anything below 60 rpm is not running
	/**
	 * Also check if there were no trigger events
	 */
	bool noTriggerEventsForTooLong = nowNt - engine->triggerCentral.previousShaftEventTimeNt >= US2NT(US_PER_SECOND_LL);
	if (noRpmEventsForTooLong || noTriggerEventsForTooLong) {
		return false;
	}

	return true;
}

void RpmCalculator::assignRpmValue(float floatRpmValue DECLARE_ENGINE_PARAMETER_SUFFIX) {
	previousRpmValue = rpmValue;
	// we still persist integer RPM! todo: figure out the next steps
	rpmValue = floatRpmValue;
	if (rpmValue <= 0) {
		oneDegreeUs = NAN;
	} else {
		// here it's really important to have more precise float RPM value, see #796
		oneDegreeUs = getOneDegreeTimeUs(floatRpmValue);
		if (previousRpmValue == 0) {
			/**
			 * this would make sure that we have good numbers for first cranking revolution
			 * #275 cranking could be improved
			 */
			ENGINE(periodicFastCallback(PASS_ENGINE_PARAMETER_SIGNATURE));
		}
	}
}

void RpmCalculator::setRpmValue(float value DECLARE_ENGINE_PARAMETER_SUFFIX) {
	assignRpmValue(value PASS_ENGINE_PARAMETER_SUFFIX);
	spinning_state_e oldState = state;
	// Change state
	if (rpmValue == 0) {
		state = STOPPED;
	} else if (rpmValue >= CONFIG(cranking.rpm)) {
		state = RUNNING;
	} else if (state == STOPPED || state == SPINNING_UP) {
		/**
		 * We are here if RPM is above zero but we have not seen running RPM yet.
		 * This gives us cranking hysteresis - a drop of RPM during running is still running, not cranking.
		 */
		state = CRANKING;
	}
#if EFI_ENGINE_CONTROL
	// This presumably fixes injection mode change for cranking-to-running transition.
	// 'isSimultanious' flag should be updated for events if injection modes differ for cranking and running.
	if (state != oldState) {
		engine->injectionEvents.addFuelEvents(PASS_ENGINE_PARAMETER_SIGNATURE);
	}
#endif
}

spinning_state_e RpmCalculator::getState() const {
	return state;
}

void RpmCalculator::onNewEngineCycle() {
	revolutionCounterSinceBoot++;
	revolutionCounterSinceStart++;
}

uint32_t RpmCalculator::getRevolutionCounterM(void) const {
	return revolutionCounterSinceBoot;
}

void RpmCalculator::setStopped(DECLARE_ENGINE_PARAMETER_SIGNATURE) {
	revolutionCounterSinceStart = 0;
	if (rpmValue != 0) {
		assignRpmValue(0 PASS_ENGINE_PARAMETER_SUFFIX);
		scheduleMsg(logger, "engine stopped");
	}
	state = STOPPED;
}

void RpmCalculator::setStopSpinning(DECLARE_ENGINE_PARAMETER_SIGNATURE) {
	isSpinning = false;
	setStopped(PASS_ENGINE_PARAMETER_SIGNATURE);
}

void RpmCalculator::setSpinningUp(efitick_t nowNt DECLARE_ENGINE_PARAMETER_SUFFIX) {
	if (!CONFIG(isFasterEngineSpinUpEnabled))
		return;
	// Only a completely stopped and non-spinning engine can enter the spinning-up state.
	if (isStopped(PASS_ENGINE_PARAMETER_SIGNATURE) && !isSpinning) {
		state = SPINNING_UP;
		engine->triggerCentral.triggerState.spinningEventIndex = 0;
		isSpinning = true;
	}
	// update variables needed by early instant RPM calc.
	if (isSpinningUp(PASS_ENGINE_PARAMETER_SIGNATURE)) {
		engine->triggerCentral.triggerState.setLastEventTimeForInstantRpm(nowNt PASS_ENGINE_PARAMETER_SUFFIX);
	}
	/**
	 * Update ignition pin indices if needed. Here we potentially switch to wasted spark temporarily.
	 */
	prepareIgnitionPinIndices(getCurrentIgnitionMode(PASS_ENGINE_PARAMETER_SIGNATURE) PASS_ENGINE_PARAMETER_SUFFIX);
}

/**
 * @brief Shaft position callback used by RPM calculation logic.
 *
 * This callback should always be the first of trigger callbacks because other callbacks depend of values
 * updated here.
 * This callback is invoked on interrupt thread.
 */
void rpmShaftPositionCallback(trigger_event_e ckpSignalType,
		uint32_t index DECLARE_ENGINE_PARAMETER_SUFFIX) {
	efitick_t nowNt = getTimeNowNt();
	efiAssertVoid(CUSTOM_ERR_6632, getCurrentRemainingStack() > EXPECTED_REMAINING_STACK, "lowstckRCL");

	RpmCalculator *rpmState = &engine->rpmCalculator;

	if (index == 0) {
		ENGINE(m.beforeRpmCb) = getTimeNowLowerNt();

		bool hadRpmRecently = rpmState->checkIfSpinning(nowNt PASS_ENGINE_PARAMETER_SUFFIX);

		if (hadRpmRecently) {
			efitick_t diffNt = nowNt - rpmState->lastRpmEventTimeNt;
		/**
		 * Four stroke cycle is two crankshaft revolutions
		 *
		 * We always do '* 2' because the event signal is already adjusted to 'per engine cycle'
		 * and each revolution of crankshaft consists of two engine cycles revolutions
		 *
		 */
			if (diffNt == 0) {
				rpmState->setRpmValue(NOISY_RPM PASS_ENGINE_PARAMETER_SUFFIX);
			} else {
				int mult = (int)getEngineCycle(engine->getOperationMode(PASS_ENGINE_PARAMETER_SIGNATURE)) / 360;
				float rpm = 60.0 * US2NT(US_PER_SECOND_LL) * mult / diffNt;
				rpmState->setRpmValue(rpm > UNREALISTIC_RPM ? NOISY_RPM : rpm PASS_ENGINE_PARAMETER_SUFFIX);
			}
		}
		rpmState->onNewEngineCycle();
		rpmState->lastRpmEventTimeNt = nowNt;
		ENGINE(m.rpmCbTime) = getTimeNowLowerNt() - ENGINE(m.beforeRpmCb);
	}


#if EFI_SENSOR_CHART
	// this 'index==0' case is here so that it happens after cycle callback so
	// it goes into sniffer report into the first position
	if (ENGINE(sensorChartMode) == SC_TRIGGER) {
		angle_t crankAngle = getCrankshaftAngleNt(nowNt PASS_ENGINE_PARAMETER_SUFFIX);
		int signal = 1000 * ckpSignalType + index;
		scAddData(crankAngle, signal);
	}
#endif /* EFI_SENSOR_CHART */

	if (rpmState->isSpinningUp(PASS_ENGINE_PARAMETER_SIGNATURE)) {
		// we are here only once trigger is synchronized for the first time
		// while transitioning  from 'spinning' to 'running'
		// Replace 'normal' RPM with instant RPM for the initial spin-up period
		engine->triggerCentral.triggerState.movePreSynchTimestamps(PASS_ENGINE_PARAMETER_SIGNATURE);
		int prevIndex;
		int instantRpm = engine->triggerCentral.triggerState.calculateInstantRpm(&prevIndex, nowNt PASS_ENGINE_PARAMETER_SUFFIX);
		// validate instant RPM - we shouldn't skip the cranking state
		instantRpm = minI(instantRpm, CONFIG(cranking.rpm) - 1);
		rpmState->assignRpmValue(instantRpm PASS_ENGINE_PARAMETER_SUFFIX);
#if 0
		scheduleMsg(logger, "** RPM: idx=%d sig=%d iRPM=%d", index, ckpSignalType, instantRpm);
#endif
	}
}

static scheduling_s tdcScheduler[2];

static char rpmBuffer[_MAX_FILLER];

/**
 * This callback has nothing to do with actual engine control, it just sends a Top Dead Center mark to the rusEfi console
 * digital sniffer.
 */
static void onTdcCallback(Engine *engine) {
#if EFI_UNIT_TEST
	if (!engine->needTdcCallback) {
		return;
	}
#endif /* EFI_UNIT_TEST */
	EXPAND_Engine;
	itoa10(rpmBuffer, GET_RPM());
#if EFI_ENGINE_SNIFFER
	waveChart.startDataCollection();
#endif
	addEngineSnifferEvent(TOP_DEAD_CENTER_MESSAGE, (char* ) rpmBuffer);
}

/**
 * This trigger callback schedules the actual physical TDC callback in relation to trigger synchronization point.
 */
static void tdcMarkCallback(trigger_event_e ckpSignalType,
		uint32_t index0 DECLARE_ENGINE_PARAMETER_SUFFIX) {
	(void) ckpSignalType;
	bool isTriggerSynchronizationPoint = index0 == 0;
	if (isTriggerSynchronizationPoint && ENGINE(isEngineChartEnabled)) {
		// two instances of scheduling_s are needed to properly handle event overlap
		int revIndex2 = getRevolutionCounter() % 2;
		int rpm = GET_RPM();
		// todo: use tooth event-based scheduling, not just time-based scheduling
		if (isValidRpm(rpm)) {
			scheduleByAngle(&tdcScheduler[revIndex2], tdcPosition(),
					(schfunc_t) onTdcCallback, engine PASS_ENGINE_PARAMETER_SUFFIX);
		}
	}
}


/**
 * @return Current crankshaft angle, 0 to 720 for four-stroke
 */
float getCrankshaftAngleNt(efitick_t timeNt DECLARE_ENGINE_PARAMETER_SUFFIX) {
	efitick_t timeSinceZeroAngleNt = timeNt
			- engine->rpmCalculator.lastRpmEventTimeNt;

	/**
	 * even if we use 'getOneDegreeTimeUs' macros here, it looks like the
	 * compiler is not smart enough to figure out that "A / ( B / C)" could be optimized into
	 * "A * C / B" in order to replace a slower division with a faster multiplication.
	 */
	int rpm = GET_RPM();
	return rpm == 0 ? NAN : timeSinceZeroAngleNt / getOneDegreeTimeNt(rpm);
}

void initRpmCalculator(Logging *sharedLogger DECLARE_ENGINE_PARAMETER_SUFFIX) {
	logger = sharedLogger;
	if (hasFirmwareError()) {
		return;
	}

	addTriggerEventListener(tdcMarkCallback, "chart TDC mark", engine);

	addTriggerEventListener(rpmShaftPositionCallback, "rpm reporter", engine);
}

/**
 * Schedules a callback 'angle' degree of crankshaft from now.
 * The callback would be executed once after the duration of time which
 * it takes the crankshaft to rotate to the specified angle.
 */
void scheduleByAngle(scheduling_s *timer, angle_t angle,
		schfunc_t callback, void *param DECLARE_ENGINE_PARAMETER_SUFFIX) {
	float delayUs = ENGINE(rpmCalculator.oneDegreeUs) * angle;
	ENGINE(executor.scheduleForLater(timer, (int) delayUs, callback, param));
}

#else
RpmCalculator::RpmCalculator() {

}

#endif /* EFI_SHAFT_POSITION_INPUT */