/**	
 * |----------------------------------------------------------------------
 * | Copyright (c) 2016 Tilen MAJERLE
 * |  
 * | 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, sublicense, and/or sell copies of the Software, 
 * | and to permit persons to whom the Software is furnished to do so, 
 * | subject to the following conditions:
 * | 
 * | The above copyright notice and this permission notice shall be
 * | included in all copies or substantial portions of the Software.
 * | 
 * | 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. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * | HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * | WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING 
 * | FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * | OTHER DEALINGS IN THE SOFTWARE.
 * |----------------------------------------------------------------------
 */
#include "tm_stm32_button.h"

/* Button states */
#define BUTTON_STATE_START        0
#define BUTTON_STATE_DEBOUNCE     1
#define BUTTON_STATE_PRESSED      2
#define BUTTON_STATE_WAITRELEASE  3

/* Internal structure */
typedef struct {
	TM_BUTTON_t* Buttons[BUTTON_MAX_BUTTONS];
	uint16_t ButtonsCount;
} TM_BUTTON_INT_t;
static TM_BUTTON_INT_t Buttons;

/* Internal functions */
static void TM_BUTTON_INT_CheckButton(TM_BUTTON_t* ButtonStruct);

TM_BUTTON_t* TM_BUTTON_Init(GPIO_TypeDef* GPIOx, uint16_t GPIO_Pin, uint8_t ButtonState, void (*ButtonHandler)(TM_BUTTON_t*, TM_BUTTON_PressType_t)) {
	TM_BUTTON_t* ButtonStruct;
	TM_GPIO_PuPd_t P;
	
	/* Init delay function */
	TM_DELAY_Init();
	
	/* Check if available */
	if (Buttons.ButtonsCount >= BUTTON_MAX_BUTTONS) {
		return NULL;
	}
	
	/* Allocate memory for button */
	ButtonStruct = (TM_BUTTON_t *) malloc(sizeof(TM_BUTTON_t));
	
	/* Check if allocated */
	if (ButtonStruct == NULL) {
		return NULL;
	}
	
	/* Save settings */
	ButtonStruct->GPIOx = GPIOx;
	ButtonStruct->GPIO_Pin = GPIO_Pin;
	ButtonStruct->GPIO_State = ButtonState ? 1 : 0;
	ButtonStruct->ButtonHandler = ButtonHandler;
	ButtonStruct->State = BUTTON_STATE_START;
	
	/* Set default values */
	ButtonStruct->PressNormalTime = BUTTON_NORMAL_PRESS_TIME;
	ButtonStruct->PressLongTime = BUTTON_LONG_PRESS_TIME;
	ButtonStruct->PressDebounceTime = BUTTON_DEBOUNCE_TIME;
	
	/* Init pin with pull resistor */
	if (ButtonStruct->GPIO_State) {
		/* Pulldown */
		P = TM_GPIO_PuPd_DOWN;
	} else {
		/* Pullup */
		P = TM_GPIO_PuPd_UP;
	}
	
	/* Init GPIO pin as input with proper pull resistor */
	TM_GPIO_Init(GPIOx, GPIO_Pin, TM_GPIO_Mode_IN, TM_GPIO_OType_PP, P, TM_GPIO_Speed_Low);
	
	/* Save button */
	Buttons.Buttons[Buttons.ButtonsCount++] = ButtonStruct;
	
	/* Return button pointer */
	return ButtonStruct;
}

TM_BUTTON_t* TM_BUTTON_SetPressTime(TM_BUTTON_t* ButtonStruct, uint16_t Normal, uint16_t Long) {
	/* Set values */
	ButtonStruct->PressNormalTime = Normal;
	ButtonStruct->PressLongTime = Long;
	
	/* Return pointer */
	return ButtonStruct;
}

void TM_BUTTON_Update(void) {
	uint16_t i;
	
	/* Go through all buttons */
	for (i = 0; i < Buttons.ButtonsCount; i++) {
		/* Check button */
		TM_BUTTON_INT_CheckButton(Buttons.Buttons[i]);
	}
}

/* Internal functions */
static void TM_BUTTON_INT_CheckButton(TM_BUTTON_t* ButtonStruct) {
	uint32_t now, status;
	
	/* Read values */
	now = TM_DELAY_Time();
	status = TM_GPIO_GetInputPinValue(ButtonStruct->GPIOx, ButtonStruct->GPIO_Pin);
	
	/* First stage */
	if (ButtonStruct->State == BUTTON_STATE_START) {
		/* Check if pressed */
		if (status == ButtonStruct->GPIO_State) {
			/* Button pressed, go to stage BUTTON_STATE_START */
			ButtonStruct->State = BUTTON_STATE_DEBOUNCE;
			
			/* Save pressed time */
			ButtonStruct->StartTime = now;
		}
	}

	if (ButtonStruct->State == BUTTON_STATE_DEBOUNCE) {
		/* Button still pressed */
		/* Check for debounce */
		if (status == ButtonStruct->GPIO_State) {
			if ((now - ButtonStruct->StartTime) > ButtonStruct->PressDebounceTime) {
				/* Button debounce OK, Goto Normal Press */
				ButtonStruct->State = BUTTON_STATE_PRESSED;

				/* Try to call user function */
				if (ButtonStruct->ButtonHandler) {
					/* Call function callback */
					ButtonStruct->ButtonHandler(ButtonStruct, TM_BUTTON_PressType_OnPressed);
				}
			}
		} else if (status != ButtonStruct->GPIO_State) {
			/* Not pressed */
			/* It was bounce, start over */
			/* Go to state BUTTON_STATE_START */
			ButtonStruct->State = BUTTON_STATE_START;
		}
	}
	
	if (ButtonStruct->State == BUTTON_STATE_PRESSED) {
		/* Button still pressed */
		/* Check for long press */
		if (status == ButtonStruct->GPIO_State) {
			if ((now - ButtonStruct->StartTime) > ButtonStruct->PressLongTime) {
				/* Button pressed OK, call function */
				if (ButtonStruct->ButtonHandler) {
					/* Call function callback */
					ButtonStruct->ButtonHandler(ButtonStruct, TM_BUTTON_PressType_Long);
				}
				
				/* Go to stage BUTTON_STATE_WAITRELEASE */
				ButtonStruct->State = BUTTON_STATE_WAITRELEASE;
			}
		} else if (status != ButtonStruct->GPIO_State) {
			/* Not pressed */
			if ((now - ButtonStruct->StartTime) > ButtonStruct->PressNormalTime) {
				/* Button pressed OK, call function */
				if (ButtonStruct->ButtonHandler) {
					/* Call function callback */
					ButtonStruct->ButtonHandler(ButtonStruct, TM_BUTTON_PressType_Normal);
				}
				
				/* Go to stage BUTTON_STATE_WAITRELEASE */
				ButtonStruct->State = BUTTON_STATE_WAITRELEASE;
			} else {
				/* Go to state BUTTON_STATE_START */
				ButtonStruct->State = BUTTON_STATE_START;
			}
		} else {
			/* Go to state BUTTON_STATE_START */
			ButtonStruct->State = BUTTON_STATE_START;
		}
	}
	
	if (ButtonStruct->State == BUTTON_STATE_WAITRELEASE) {
		/* Wait till button released */
		if (status != ButtonStruct->GPIO_State) {
			/* Go to stage 0 again */
			ButtonStruct->State = BUTTON_STATE_START;
		}
	}
	
	/* Save current status */
	ButtonStruct->LastStatus = status;
}