/*
 * motion.c
 *
 *  Created on: 20.05.2019
 *      Author: Thorsten Sonntag
 */

#include <stdint.h>
#include <string.h>
#include <stdlib.h>
#include <math.h>
#include "motion.h"
#include "data_central.h"
#include "t7.h"
#include "t3.h"
#include "settings.h"

#define	STABLE_STATE_COUNT			2	/* number of count to declare a state as stable (at the moment based on 100ms) */
#define STABLE_STATE_TIMEOUT		5	/* Detection shall be aborted if a movement state is stable for more than 500ms */

#define SECTOR_WINDOW				80.0  	/* Pitch window which is used for custom view projection */
#define SECTOR_WINDOW_MAX			120.0  	/* Pitch window which will be greater than the divers field of view */
#define SECTOR_HYSTERY				2		/* Additional offset to avoid fast changing displays */
#define SECTOR_BORDER				400.0	/* Define a value which is out of limit to avoid not wanted key events */
#define SECTOR_FILTER				10		/* Define speed for calculated angle to follow real value */

#define SECTOR_MAX					24		/* maximum number of sectors */
#define SECTOR_SCROLL				7		/* number of sectors used for scroll detection */

detectionState_t detectionState = DETECT_NOTHING;
SSector sectorDetection;


uint8_t GetSectorForPitch(float pitch)
{
	static uint8_t lastsector = 0;
	float newPitch;
	uint8_t sector = 0;

	newPitch = pitch + sectorDetection.offset + sectorDetection.center;		/* do not use negative values and consider offset to center position */
	if (newPitch < 0.0)							/* clip value */
	{
		newPitch = 0.0;
	}
	if (newPitch > sectorDetection.window)							/* clip value */
	{
		newPitch = sectorDetection.window;
	}

	/* switch to other sector? */
	if((newPitch > sectorDetection.upperborder) || (newPitch <= sectorDetection.lowerborder))
	{
		sector = (uint16_t) newPitch / sectorDetection.size;
		sectorDetection.lowerborder = sector * sectorDetection.size - SECTOR_HYSTERY;
		sectorDetection.upperborder = (sector + 1) * sectorDetection.size + SECTOR_HYSTERY;
		lastsector = sector;
	}

	return lastsector;
}

void DefinePitchSectors(float centerPitch,uint8_t numOfSectors)
{
	if(numOfSectors == CUSTOMER_DEFINED_VIEWS)
	{
		if(settingsGetPointer()->design == 3)		/* Big font view ? */
		{
			sectorDetection.count =  t3_GetEnabled_customviews();
		}
		else
		{
			sectorDetection.count =  t7_GetEnabled_customviews();
		}
		if(sectorDetection.count > 7)
		{
			sectorDetection.count = 7;	/* more views are hard to manually control */
		}
	}
	else
	if(numOfSectors != CUSTOMER_KEEP_LAST_SECTORS)
	{
		sectorDetection.count = numOfSectors;
	}

	if(sectorDetection.count == SECTOR_MAX)
	{
		sectorDetection.window = SECTOR_WINDOW_MAX;
	}
	else
	{
		sectorDetection.window = SECTOR_WINDOW;
	}

	sectorDetection.offset = (centerPitch - (sectorDetection.window / 2)) * -1.0;
	sectorDetection.size = sectorDetection.window / sectorDetection.count;
	sectorDetection.center = 0;

/* reset border values */
	sectorDetection.lowerborder = SECTOR_BORDER;
	sectorDetection.upperborder = SECTOR_BORDER * -1.0;
/* get the current sector */
	sectorDetection.current = GetSectorForPitch(stateRealGetPointer()->lifeData.compass_pitch);
	sectorDetection.target = sectorDetection.current;
/* do a small adjustment to center pitch to make sure the actual pitch is in the center of the current sector */
	sectorDetection.center = (sectorDetection.upperborder) - ((sectorDetection.size + 2 *SECTOR_HYSTERY) / 2.0) - (centerPitch + sectorDetection.offset);

}

void InitMotionDetection(void)
{
	sectorDetection.target = 0;
	sectorDetection.current = 0;
	sectorDetection.size = 0;
	sectorDetection.count = 0;

	switch(settingsGetPointer()->MotionDetection)
	{
		case MOTION_DETECT_SECTOR: DefinePitchSectors(0,CUSTOMER_DEFINED_VIEWS);
			break;
		case MOTION_DETECT_MOVE: DefinePitchSectors(0,SECTOR_MAX);
			break;
		case MOTION_DETECT_SCROLL: DefinePitchSectors(0,SECTOR_SCROLL);
			break;
		default:
			break;
	}

}

/* Map the current pitch value to a sector and create button event in case the sector is left */
detectionState_t detectSectorButtonEvent(float curPitch)
{
	static uint8_t lastTargetSector = 0;
	uint8_t newTargetSector;
	uint8_t PitchEvent = DETECT_NOTHING;

/* only change sector if reading is stable */
	newTargetSector = GetSectorForPitch(stateRealGetPointer()->lifeData.compass_pitch);
	if(lastTargetSector == newTargetSector)
	{
		sectorDetection.target = newTargetSector;
	}
	lastTargetSector = newTargetSector;
	if(sectorDetection.target != sectorDetection.current)
	{
		 if(sectorDetection.target > sectorDetection.current)
		 {
			 sectorDetection.current++;
			PitchEvent = DETECT_POS_PITCH;
		 }
		 else
		 {
			 sectorDetection.current--;
			 PitchEvent = DETECT_NEG_PITCH;
		 }
	}
	return PitchEvent;
}

/* Check if pitch is not in center position and trigger a button action if needed */
detectionState_t detectScrollButtonEvent(float curPitch)
{
	static uint8_t	delayscroll = 0;		/* slow down the number of scroll events */

	uint8_t PitchEvent = DETECT_NOTHING;
	uint8_t newSector;

	if(delayscroll == 0)
	{
		newSector = GetSectorForPitch(stateRealGetPointer()->lifeData.compass_pitch);
		/* for scroll detection the motion windoe is split into 6 sectors => set event accoring to the sector number*/
		switch(newSector)
		{
			case 0:
			case 1:	PitchEvent = DETECT_POS_PITCH;
				break;
			case 5:
			case 6:	PitchEvent = DETECT_NEG_PITCH;
				break;
			default:
				break;
		}
		if(PitchEvent != DETECT_NOTHING)
		{
			delayscroll = 5;
		}
	}
	else
	{
		delayscroll--;
	}
	return PitchEvent;
}


/* Detect if user is generating an pitch including return to starting position */
/* This is done by feeding the past movements value per value into a state machine */
detectionState_t detectPitch(float currentPitch)
{
	static uint8_t lastSector = 0;
	static uint8_t startSector = 0;
	static uint8_t stableCnt = 0;

	uint8_t curSector;

	if((detectionState == DETECT_NEG_PITCH) || (detectionState == DETECT_POS_PITCH))	/* discard last detection */
	{
		detectionState = DETECT_NOTHING;
	}

	curSector = GetSectorForPitch(stateRealGetPointer()->lifeData.compass_pitch);

	/* feed value into state machine */
	switch (detectionState)
	{
			case DETECT_NOTHING: 	if(curSector != lastSector)	/* detect a stable condition before evaluating for the next move */
									{
										stableCnt=0;
									}

									if(stableCnt > STABLE_STATE_COUNT)
									{
										detectionState = DETECT_START;
										stableCnt = 0;
										startSector = lastSector;
									}
				break;
			case DETECT_START:		if(curSector != lastSector)
									{
										if(abs(curSector - startSector) > 1)
										{
											if(curSector > lastSector)
											{
												detectionState = DETECT_POS_MOVE;
											}
											else
											{
												detectionState = DETECT_NEG_MOVE;
											}
											stableCnt = 0;
											startSector = lastSector;
										}
									}
				break;
			case DETECT_NEG_MOVE:
			case DETECT_POS_MOVE:	if(curSector == lastSector)		/* Moved to a max? */
									{
										if(abs(startSector - curSector) > 2)
										{
											detectionState++;
											stableCnt = 0;
										}
										if(stableCnt > 2)
										{
											detectionState = DETECT_NOTHING;
											stableCnt = 0;
										}
									}
				break;
			case DETECT_MAXIMA:
			case DETECT_MINIMA:		if(curSector != lastSector)		/* reset timeout detection */
									{
										detectionState++;
										stableCnt = 0;
									}
				break;
			case DETECT_RISEBACK:
			case DETECT_FALLBACK:
									if(curSector == lastSector)		/* check if we are back at start position at end of movement */
									{
										if(abs(startSector - curSector) <= 1)
										{
											if(stableCnt > 2)
											{
												detectionState++;
												stableCnt = 0;
											}
										}
									}
								break;
			default:
				detectionState = DETECT_NOTHING;
				break;
	}
	if(detectionState != DETECT_START)
	{
		stableCnt++;
	}
	lastSector = curSector;
	if(stableCnt > STABLE_STATE_TIMEOUT)
	{
		detectionState = DETECT_NOTHING;
		stableCnt = 0;
	}

	return detectionState;
}