#include "multi_button.h"

#define EVENT_CB(ev)   if((handle->event)&ev)handle->cb(handle,handle->event)
	
//button handle list head.
static struct Button* head_handle = NULL;

/**
  * @brief  Initializes the button struct handle.
  * @retval None
  */
void button_init(void)
{
	head_handle = NULL;
}

/**
  * @brief  Button driver core function, driver state machine.
  * @param  handle: the button handle strcut.
  * @param  pin_level: the button status 0:unpress 1:pressed.
  * @param  cb: the button press call function.
  * @param  event: the button event trigger mask.
  * @retval None
  */
void button_attach(struct Button* handle, uint8_t(*pin_level)(), BtnCallback cb, PressEvent event)
{
    memset(handle, 0, sizeof(struct Button));
    handle->event = (uint8_t)BTN_UNPRESS;
    handle->hal_button_Level = pin_level;
    handle->button_level = handle->hal_button_Level();
	handle->cb = cb;

	/* start the button */
	button_start( handle );
}

/**
  * @brief  Inquire the button event happen.
  * @param  handle: the button handle strcut.
  * @retval button event.
  */
PressEvent get_button_event(struct Button* handle)
{
	return (PressEvent)(handle->event);
}

/**
  * @brief  Button driver core function, driver state machine.
  * @param  handle: the button handle strcut.
  * @retval None
  */
void button_handler(struct Button* handle)
{
	uint8_t read_gpio_level = handle->hal_button_Level();

	//ticks counter working..
	if((handle->state) > 0) handle->ticks++;

	/*------------button debounce handle---------------*/
	if(read_gpio_level != handle->button_level) { //not equal to prev one
		//continue read 3 times same new level change
		if(++(handle->debounce_cnt) >= DEBOUNCE_TICKS) {
			handle->button_level = read_gpio_level;
			handle->debounce_cnt = 0;
		}
	} else { //leved not change ,counter reset.
		handle->debounce_cnt = 0;
	}

    handle->event = read_gpio_level;
	/*-----------------State machine-------------------*/
	switch (handle->state) {
	case 0:
		if(handle->button_level == BTN_PRESSED) {	//start press down
			handle->event |= (uint8_t)PRESS_DOWN;
			EVENT_CB(PRESS_DOWN);
			handle->ticks = 0;
			handle->repeat = 1;
			handle->state = 1;
		} else {
			handle->event |= (uint8_t)BTN_UNPRESS;
		}
		break;

	case 1:
		if(handle->button_level != BTN_PRESSED) { //released press up
			handle->event |= (uint8_t)PRESS_UP;
			EVENT_CB(PRESS_UP);
			handle->ticks = 0;
			handle->state = 2;

		} else if(handle->ticks > LONG_TICKS) {
			handle->event |= (uint8_t)LONG_RRESS_START;
			EVENT_CB(LONG_RRESS_START);
			handle->state = 5;
		}
		break;

	case 2:
		if(handle->button_level == BTN_PRESSED) { //press down again
			handle->event |= (uint8_t)PRESS_DOWN;
			EVENT_CB(PRESS_DOWN);
			handle->repeat++;
			if(handle->repeat == 2) {
				EVENT_CB(DOUBLE_CLICK); // repeat hit
			} 
			EVENT_CB(PRESS_REPEAT); // repeat hit
			handle->ticks = 0;
			handle->state = 3;
		} else if(handle->ticks > SHORT_TICKS) { //released timeout
			if(handle->repeat == 1) {
				handle->event |= (uint8_t)SINGLE_CLICK;
				EVENT_CB(SINGLE_CLICK);
			} else if(handle->repeat == 2) {
				handle->event |= (uint8_t)DOUBLE_CLICK;
			}
			handle->state = 0;
		}
		break;

	case 3:
		if(handle->button_level != BTN_PRESSED) { //released press up
			handle->event |= (uint8_t)PRESS_UP;
			EVENT_CB(PRESS_UP);
			if(handle->ticks < SHORT_TICKS) {
				handle->ticks = 0;
				handle->state = 2; //repeat press
			} else {
				handle->state = 0;
			}
		}
		break;

	case 5:
		if(handle->button_level == BTN_PRESSED) {
			//continue hold trigger
			handle->event |= (uint8_t)LONG_PRESS_HOLD;
			EVENT_CB(LONG_PRESS_HOLD);

		} else { //releasd
			handle->event |= (uint8_t)PRESS_UP;
			EVENT_CB(PRESS_UP);
			handle->state = 0; //reset
		}
		break;
	}
}

/**
  * @brief  Start the button work, add the handle into work list.
  * @param  handle: target handle strcut.
  * @retval 0: succeed. -1: already exist.
  */
int button_start(struct Button* handle)
{
	struct Button* target = head_handle;
	while(target) {
		if(target == handle) return -1;	//already exist.
		target = target->next;
	}
	handle->next = head_handle;
	head_handle = handle;
	return 0;
}

/**
  * @brief  Stop the button work, remove the handle off work list.
  * @param  handle: target handle strcut.
  * @retval None
  */
void button_stop(struct Button* handle)
{
	struct Button** curr;
	for(curr = &head_handle; *curr; ) {
		struct Button* entry = *curr;
		if (entry == handle) {
			*curr = entry->next;
//			free(entry);
		} else
			curr = &entry->next;
	}
}

/**
  * @brief  background ticks, timer repeat invoking interval 5ms.
  * @param  None.
  * @retval None
  */
void button_ticks()
{
	struct Button* target;
	for(target=head_handle; target; target=target->next) {
		button_handler(target);
	}
}