#include <avr/io.h>
#include <avr/interrupt.h>
#include <avr/sleep.h>
#include <util/delay.h>
#include <stdlib.h> // for NULL

#include "lights.h"

#define WAKEUP_LIMIT	5	// times 100 ms
static uint16_t button_start[3];
union {
	unsigned char all;
	struct {
		unsigned char btn1 : 1;
		unsigned char btn2 : 1;
		unsigned char brake : 1;
	};
} button_state, prev_state;

static unsigned char user_params[MAX_USER_PARAMS] = { 0, 0, 0 };
static unsigned char user_params_max[MAX_USER_PARAMS] = { 3, 2, 2 };

static unsigned char user_params_state = 0;
	/*
	 * Here 0 means "no setup currently in progress",
	 * 1 .. MAX_USER_PARAMS means "now short presses increase or decrease
	 *           the value of user_params[user_params_state-1]"
	 */

static uint16_t user_params_starttime;

static void inline set_status_led(unsigned char n, pattern_t *pattern)
{
	led_set_pattern(n + N_PWMLEDS, pattern);
}

unsigned char buttons_setup_in_progress()
{
	if (user_params_state // setup in progress ...
		// or at least one button is pressed:
		|| prev_state.btn1
		|| prev_state.btn2)
		return 1;
	return 0;
}

pattern_t *buttons_setup_status0_pattern_select()
{
	if (user_params_state) // Setup in progress
		return number_pattern(user_params_state, 1);
	else
		return NULL;
}

pattern_t *buttons_setup_status1_pattern_select()
{
	if (user_params_state) // Setup in progress
		return number_pattern(
			1 + user_params[user_params_state-1],
			1
		);
	else
		return NULL;
}

unsigned char get_user_param(unsigned char param)
{
	if (param < MAX_USER_PARAMS)
		return user_params[param];
	return 0; // FIXME: internal error?
}

static inline void short_press(unsigned char button)
{
	unsigned char param;

	if (user_params_state == 0) {
		if (button == 0)
			toggle_dim_mode();
		else
			set_panic_mode();
		return;
	}

	param = user_params_state-1;

	if (button == 0) {
		if (user_params[param])
			user_params[param]--;
		else
			user_params[param] = user_params_max[param]-1;
	} else {
		user_params[param]++;

		if (user_params[param] >= user_params_max[param])
			user_params[param] = 0;
	}
	// FIXME: notify somebody about user_params change?

	set_status_led(1, buttons_setup_status1_pattern_select());

	user_params_starttime = jiffies;
}

static inline void long_press(unsigned char button)
{
	if (button == 0) {
		power_down();
		return;
	}

	// button 1 - cycle through states
	user_params_state++;

	if (user_params_state > MAX_USER_PARAMS)
		user_params_state = 1;

	set_status_led(0, buttons_setup_status0_pattern_select());
	set_status_led(1, buttons_setup_status1_pattern_select());
	user_params_starttime = jiffies;
}

void init_buttons()
{
	DDRA &= ~_BV(PA4); // set as input
	DDRA |= _BV(PA3); // output
	PORTA &= ~(_BV(PA3) | _BV(PA4));  // PA4 disable internal pull-up
					// PA3 set to zero

	GIMSK &= ~(_BV(PCIE0) | _BV(PCIE1)); // disable pin-change IRQs
	PCMSK0 = 0; // disable pin-change IRQs on all pins of port A
	PCMSK1 = 0; // disable pin-change IRQs on all pins of port B

	button_start[0] = 0;
	button_start[1] = 0;
	button_start[2] = 0;

	prev_state.all    = 0;
	button_state.all  = 0;
	user_params_state = 0;
}

void susp_buttons()
{
	DDRA &= ~(_BV(PA3) | _BV(PA4)); // set as input
	PORTA |= _BV(PA4);  // enable internal pull-up
	PORTA &= ~_BV(PA3); // disable pull-up

	GIMSK &= ~_BV(PCIE0);
	GIMSK |= _BV(PCIE1);

	PCMSK0 = _BV(PCINT4);
		// disable pin-change IRQs on all pins except PA4
	PCMSK1 = 0; // disable pin-change IRQs on all pins of port B
}

static void handle_button(unsigned char button, unsigned char cur,
	unsigned char prev)
{
	if (cur && !prev) {                   // --- just pressed ---
		button_start[button] = jiffies;
		set_status_led(button, NULL);

	} else if (cur && prev) {           // --- is still pressed ---
		uint16_t duration = jiffies - button_start[button];

		if (duration > 160) {
			set_status_led(button, on1_pattern);
				// acknowledge long press
		}
	} else if (!cur && prev) {            // --- just released ---
		uint16_t duration = jiffies - button_start[button];

		if (duration > 6 && duration < 60) {
			short_press(button);
		} else if (duration > 160) {
			set_status_led(button, NULL);
			long_press(button);
		}
		// ignore other button-press durations
	}
}

static void handle_brake(unsigned char cur, unsigned char prev)
{
	if (cur && !prev) {                   // --- just pressed ---
		button_start[2] = jiffies;
	} else if (cur && prev) {           // --- is still pressed ---
		uint16_t duration = jiffies - button_start[2];

		if (duration > 6) {
			brake_on();
			button_start[2] = jiffies - 7; // avoid overflow
		}
	} else if (!cur && prev) {            // --- just released ---
		brake_off();
	}
}

void timer_check_buttons()
{
	handle_button(0, button_state.btn1, prev_state.btn1);
	handle_button(1, button_state.btn2, prev_state.btn2);
	handle_brake(button_state.brake, prev_state.brake);

	prev_state.all = button_state.all;

	if (user_params_state && jiffies - user_params_starttime > 1000) {
		user_params_state = 0;
		set_status_led(0, buttons_setup_status0_pattern_select());
		set_status_led(1, buttons_setup_status1_pattern_select());
	}
}

unsigned char buttons_wait_for_release()
{
	uint16_t wake_count = 0;
	unsigned char pin;

	do {
		if (wake_count++ > WAKEUP_LIMIT)
			gpio_set(0, 1); // inform the user

		_delay_ms(100);

		pin = PINA & _BV(PA4);
	} while (!(pin & _BV(PA4)));

	gpio_set(0, 0);

	return wake_count > WAKEUP_LIMIT;
}

void button_adc(uint16_t adcval)
{
#if 0
	static unsigned char count=250;
#endif
	PORTA &= ~_BV(PA3); // disable +5V to the hall probe
		// adc.c will re-enable it again

	button_state.all = 0;
	if (adcval == 0x3FF) {
		button_state.brake = 1;
	} else if (adcval > 0x240) {
		button_state.brake = 1;
		button_state.btn2 = 1;
	} else if (adcval > 0x180) {
		// nothing
	} else if (adcval > 0xc0) {
		button_state.btn2 = 1;
	} else {
		button_state.btn1 = 1;
	}

#if 0
	if (--count)
		return;

	count = 250;
	log_word(adcval);
	log_flush();
#endif
}

ISR(PCINT_vect)
{
	// empty - let it wake us from sleep, but do nothing else
}