#include <avr/io.h>
#include <util/delay.h>

// stringify
#define STRINGIFY_HELPER(x)			#x
#define STRINGIFY(x)				STRINGIFY_HELPER(x)

// concatenate
#define CONCAT_HELPER(x, y)			x ## y
#define CONCAT(x, y)				CONCAT_HELPER(x, y)

// get argument
#define ARG_1(v1, v2)				v1
#define ARG_2(v1, v2)				v2
#define GET_PORT(args)				ARG_1 args
#define GET_BIT(args)				ARG_2 args

// actions on registers
#define SET(register, bit)			register |= 1 << bit
#define CLEAR(register, bit)		register &= ~(1 << bit)
#define TEST(register, bit)			register & 1 << bit
#define TOGGLE(register, bit)		register ^= 1 << bit

// actions on elements
#define SET_ELEM(elem)				SET(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define CLEAR_ELEM(elem)			CLEAR(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define TEST_ELEM(elem)				TEST(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define TOGGLE_ELEM(elem)			TOGGLE(CONCAT(PORT, GET_PORT(elem)), GET_BIT(elem))
#define MODE_OUTPUT(elem)			SET(CONCAT(DDR, GET_PORT(elem)), GET_BIT(elem))
#define MODE_INPUT(elem)			CLEAR(CONCAT(DDR, GET_PORT(elem)), GET_BIT(elem))
#define TOGGLE_PIN(elem)			SET(CONCAT(PIN, GET_PORT(elem)), GET_BIT(elem))
#define TEST_PIN(elem)				(TEST(CONCAT(PIN, GET_PORT(elem)), GET_BIT(elem)))
#define IS_PIN_SET(elem)			(TEST_PIN(elem) == 0)
#define IS_PIN_CLEAR(elem)			(TEST_PIN(elem) == 1)

// bits
#define D1	0
#define D2	1
#define D3	2
#define D4	4
#define SW1	2
#define SW2	4

// elements (port, bit)
#define LED1	(B, D1)
#define LED2	(B, D2)
#define LED3	(B, D3)
#define LED4	(B, D4)
#define BUTTON1	(D, SW1)
#define BUTTON2	(D, SW2)

#define BUTTON(id)	

// END MACROS

typedef struct {
    int *value;
    int max;
	int min;
} IncrementParams;

void print_binary(int value) {
	int mask_3 = 0b1000;
	int bit_at_3 = value & mask_3;
	int bit_at_4 = bit_at_3 << 1;
	PORTB = (value & 0b111) + bit_at_4;
}

void increment_int(IncrementParams *params) {
	int *value = params->value;
	int max = params->max;
	*value = (*value >= max) ? max : ++(*value);
}

void decrement_int(IncrementParams *params) {
	int *value = params->value;
	int min = params->min;
    *value = (*value <= min) ? min : --(*value);
}

void increment_led(void *param) {
	IncrementParams *params = (IncrementParams *)param;
	increment_int(params);
	print_binary(*(params->value));
}

void decrement_led(void *param) {
	IncrementParams *params = (IncrementParams *)param;
	decrement_int(params);
	print_binary(*(params->value));
}

void on_press(int bit, void (*action)(void*), void *params) {
	if ((TEST(PIND, bit)) == 0) {
	    action(params);
	    _delay_ms(20);
	    while ((TEST(PIND, bit)) == 0) {
	        continue;
	    }
	    _delay_ms(20);
	}
}

int main() {
	MODE_OUTPUT(LED1);
	MODE_OUTPUT(LED2);
	MODE_OUTPUT(LED3);
	MODE_OUTPUT(LED4);
	MODE_INPUT(BUTTON1);
	MODE_INPUT(BUTTON2);
	
	int value = 0;
    int max = 15;
	int min = 0;
    IncrementParams params = {&value, max};

	while(1) {
		on_press(SW1, increment_led, &params);
		on_press(SW2, decrement_led, &params);
	}
}