#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <avr/sleep.h>
#include <avr/interrupt.h>
#include <avr/wdt.h>

#include "barometer.h"
#include "display.h"
#include "util.h"

#ifdef WDT_DISABLE
# warning "WDT disabled in this build"
# define WDT_SETUP_MAYBE(x)
# define WDT_PAT_MAYBE()
#else
# define WDT_SETUP_MAYBE(x) do{wdt_enable(x);}while(0)
# define WDT_PAT_MAYBE()    do{wdt_reset();}while(0)
#endif

#define DEBUG_ALL_VAL ((1 << 1) | (1 << 2) | (1 << 3) | (1 << 4) | (1 << 5) | (1 << 6))
#define DEBUG_INIT         do{DDRB |= DEBUG_ALL_VAL;}while(0)
#define DEBUG_MARK_SET_ALL do{PORTB |= DEBUG_ALL_VAL;}while(0)
#define DEBUG_MARK_1_SET   do{PORTB |= 1 << 1;}while(0)
#define DEBUG_MARK_1_CLEAR do{PORTB &= ~(1 << 1);}while(0)
#define DEBUG_MARK_2_SET   do{PORTB |= 1 << 3;}while(0)
#define DEBUG_MARK_2_CLEAR do{PORTB &= ~(1 << 3);}while(0)
#define DEBUG_MARK_3_SET   do{PORTB |= 1 << 2;}while(0)
#define DEBUG_MARK_3_CLEAR do{PORTB &= ~(1 << 2);}while(0)
#define DEBUG_MARK_4_SET   do{PORTB |= 1 << 6;}while(0)
#define DEBUG_MARK_4_CLEAR do{PORTB &= ~(1 << 6);}while(0)
#define DEBUG_MARK_5_SET   do{PORTB |= 1 << 5;}while(0)
#define DEBUG_MARK_5_CLEAR do{PORTB &= ~(1 << 5);}while(0)
#define DEBUG_MARK_6_SET   do{PORTB |= 1 << 4;}while(0)
#define DEBUG_MARK_6_CLEAR do{PORTB &= ~(1 << 4);}while(0)

/* ISR for collecting and displaying pressure, altitude data etc */
ISR(TIMER1_COMPA_vect)
{
	DEBUG_MARK_SET_ALL;
	static volatile float setting = 1040.21; /* FIXME volatile for gdb hacks */
	static float last_height = 0;
	float pressure = 0;
	float height_m = 0;
	float rate_m_s;
	char rate_sym;
	DEBUG_MARK_1_CLEAR;
	pressure = barometer_read();
	DEBUG_MARK_2_CLEAR;
	height_m = pressure_to_metres_asl(pressure, setting);
	DEBUG_MARK_3_CLEAR;
	rate_m_s = height_m - last_height;
	last_height = height_m;
	DEBUG_MARK_4_CLEAR;

	if (rate_m_s < 0) {
		rate_sym = C_DESC;
	} else if (rate_m_s == 0) {
		rate_sym = C_IDLE;
	} else {
		rate_sym = C_ASC;
	}
	DEBUG_MARK_5_CLEAR;

	char line[LCD_WIDTH+1];
	/* line 1 */
	snprintf(line, sizeof(line), "%.1f m %c%d m/s", height_m, rate_sym, abs(rate_m_s));
	blank_to_eol(line, sizeof(line));
	display_set_cursor(0, 0);
	display_write(line);


	/* line 2 */
	snprintf(line, sizeof(line), "%.2f hPa", pressure);
	blank_to_eol(line, sizeof(line));
	display_set_cursor(0, 1);
	display_write(line);

	/* line 3 */
	snprintf(line, sizeof(line), "SET %.2f hPa", setting);
	blank_to_eol(line, sizeof(line));
	display_set_cursor(0, 2);
	display_write(line);

	/* line 4 */
	snprintf(line, sizeof(line), "%.1f ""\xdf""C", 12.3f);
	blank_to_eol(line, sizeof(line));
	display_set_cursor(0, 3);
	display_write(line);

	DEBUG_MARK_6_CLEAR;

	WDT_PAT_MAYBE();
}

int main(void)
{
	/* Initialise display before enabling interrupts */
	display_init();
	display_clear();

	DEBUG_INIT;

	/* Initialise timers for /1024 prescaler, 1 Hz comparator val */
	TCCR1B |= (1 << CS10) | (1 << CS12) | (1 << WGM12);
	TIMSK1 |= (1 << OCIE1A);
	OCR1A = F_CPU / 1024;

#ifdef USBCON
	/* Disable USB controller if one is present - this spams (latches?) USB_GEN
	 * interrupt which we're not handling for now */
	USBCON &= ~(1 << USBE);
#endif

	/* main body should take no longer than 1 second to run */
	WDT_SETUP_MAYBE(WDTO_2S);

	sei();
	while(1) {
		set_sleep_mode(SLEEP_MODE_IDLE);
		sleep_mode();
	}
}