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

#include "display.h"
#include "modem.h"
#include "system.h"

#define SHUTDOWN_THRESHOLD 2048

System rocket;

extern animation_t ohai;

uint8_t disp_buf[128];

void System::loop()
{
	static uint8_t i = 0;
	uint8_t modem_byte;
	// both buttons are pressed
	if ((PINC & (_BV(PC3) | _BV(PC7))) == 0) {
		// naptime!
		// But not before both buttons have been pressed for
		// SHUTDOWN_THRESHOLD * 0.256 ms. And then, not before both have
		// been released, because otherwise we'd go te sleep when
		// they're pressed and wake up when they're released, which
		// isn't really the point here.

		if (want_shutdown < SHUTDOWN_THRESHOLD) {
			want_shutdown++;
		}
		else {
			shutdown();

			want_shutdown = 0;
		}
	}
	else {
		want_shutdown = 0;
	}

	while (modem.buffer_available()) {
		modem_byte = modem.buffer_get();
		disp_buf[i++] = modem_byte;
		if (i == 127) {
			i = 0;
		} else if (modem_byte == 0) {
			ohai.data = disp_buf;
			ohai.length = i-1;
			display.show(&ohai);
			i = 0;
		}
	}

	display.update();
}

void System::shutdown()
{
	// turn off display to indicate we're about to shut down
	display.disable();

	modem.disable();

	// wait until both buttons are released
	while (!((PINC & _BV(PC3)) && (PINC & _BV(PC7)))) ;

	// and some more to debounce the buttons
	_delay_ms(10);

	// actual naptime

	// enable PCINT on PC3 (PCINT11) and PC7 (PCINT15) for wakeup
	PCMSK1 |= _BV(PCINT15) | _BV(PCINT11);
	PCICR |= _BV(PCIE1);

	// go to power-down mode
	SMCR = _BV(SM1) | _BV(SE);
	asm("sleep");

	// execution will resume here - disable PCINT again.
	// Don't disable PCICR, something else might need it.
	PCMSK1 &= ~(_BV(PCINT15) | _BV(PCINT11));

	// turn on display
	display.enable();

	// ... and modem
	modem.enable();
}

ISR(PCINT1_vect)
{
	// we use PCINT1 for wakeup, so we should catch it here (and do nothing)
}