/* 2015, Ralf Ramsauer
 * ralf@binary-kitchen.de
 */

#include <stdbool.h>

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

#include "io.h"
#include "uart.h"

static volatile enum {LOCKED, UNLOCKED} state = LOCKED;
static volatile bool schnapper = false;

static inline void reset_timeout(void)
{
	TCNT1 = 0;
}

void uart_handler(const unsigned char c)
{
	char retval = c;
	switch ((char)c) {
		case 'u':
			state = UNLOCKED;
			reset_timeout();
			break;

		case 'l':
			state = LOCKED;
			break;

		case 'p':
			break;

		case 's':
			if (state == UNLOCKED)
				schnapper = true;
			else
				retval = '?';
			break;

		case 'i':
			retval = (state == LOCKED) ? 'l' : 'u';
			break;

		default:
			retval = '?';
			break;
	}

	uart_putc(retval);
}

// Alle 1.137 Sekunden
ISR(TIMER1_OVF_vect)
{
	state = LOCKED;
}

// Notzu
ISR(INT0_vect)
{
	cli();

	// This code is used to prevent spurious interrupts
	_delay_ms(50);
	if (!is_button_lock())
		goto out;

	uart_putc('L');
	state = LOCKED;

out:
	sei();
}

// Notauf
ISR(INT1_vect)
{
	cli();

	// This code is used to prevent spurious interrupts
	_delay_ms(50);
	if (!is_button_unlock())
		goto out;

	uart_putc('U');

	bolzen_off();
	schnapper_on();

	_delay_ms(3000);

	schnapper_off();

out:
	sei();
}

int main(void)
{
	cli();
	io_init();

	// Wait a bit to settle down
	_delay_ms(1000);
	uart_init();
	uart_set_recv_handler(uart_handler);

	// Timer config
	TIMSK |= (1<<TOIE1);
	TIFR |= (1<<TOV1);
	TCCR1A = 0;
	TCCR1B = (1<<CS12);

	TCNT1 = 0;

	// falling edge
	MCUCR = (1<<ISC11)|(1<<ISC01);
	GIMSK |= (1<<INT0)|(1<<INT1);

	sei();

	for(;;) {
		if (state == LOCKED) {
			bolzen_on();
			schnapper = false;
			if (is_emergency_unlock()) {
				_delay_ms(200);
				if (is_emergency_unlock()) {
					uart_putc('N');
					cli();

					bolzen_off();
					schnapper_on();

					_delay_ms(3000);

					schnapper_off();
					bolzen_on();

					sei();
				}
			}
		} else if (state == UNLOCKED) {
			bolzen_off();
			if (schnapper == true) {
				schnapper = false;
				schnapper_on();
				_delay_ms(2000);
				schnapper_off();
			}
		}
	}

	return 0;
}