/*
 * GccApplication1.c
 *
 * Created: 10/8/2019 2:07:13 PM
 * Author : lenfesty
 */ 

#include "main.h"

/*
 * Pin Definitions:
 * PB2 -> OC0A output
 * PB3 -> OC1A output
 * PD2 -> Switch Input
 */
void gpio_init() {
	// Piezo Out
	DDRB |= (1 << DDB2) | (1 << DDB3);
	
	// Switch Input Setup
	DDRD &= ~(1 << DDD2);
	PORTD |= (1 << PORTD2);
}

void timer_init( ) {
	/* --- Timer 0 (8 bit) --- */
	// Set Compare mode A to toggle, and waveform generation mode to CTC
	TCCR0A = (0 << COM0A1) | (1 << COM0A0) | (1 << WGM01) | (0 << WGM00);
	// Nothing else relevant here, without setting notes
	
	/* --- Timer 1 (16 bit) --- */
	// Set compare mode A to toggle
	TCCR1A = (0 << COM1A1) | (1 << COM1A0);
	// Set waveform gen mode to CTC
	TCCR1B = (1 << WGM12);
}


// Returns true for a "successful" note, false for end of song.
bool play_beat() {
	static uint8_t duration_left[2] = {0};
    static uint16_t song_location[2] = {0};
		
	// If at end of song, restart
	if (song_location[0] == SPEAKER0_LEN) {
		song_location[0] = 0;
		song_location[1] = 0;
		return false;
	}
	
	// Set note
	for (uint8_t speaker = 0; speaker < 2; speaker++) {
		if (duration_left[speaker] == 0) {
			// Move to next note
			// Read in next note from program memory
			uint16_t beat;
			beat_t* p_beat;
			
			// Select from correct song
			if (speaker == 0) {
				beat = pgm_read_word((PGM_P*) &song_speaker0[song_location[speaker]]);
			} else {
				beat = pgm_read_word((PGM_P*) &song_speaker1[song_location[speaker]]);
			}
			
			p_beat = (beat_t*) &beat;
			
			
			// Set duration left after this beat
			duration_left[speaker] = p_beat->duration - 1;
			// Increment song location for next note
			song_location[speaker]++;
			
			// actually set note
			play_note(*p_beat, speaker);
		} else {
			// Keep handling current note
			// do nothing, it is set correctly
			duration_left[speaker]--;
		}
	}
	_delay_ms(BEAT_LENGTH * (1 - REST_FRACTION)); // Play note
	
	// Rest note if at the end of the interval
	for (uint8_t speaker = 0; speaker < 2; speaker++) {
		if (duration_left[speaker] == 0) {
			// End of note, pause here
			beat_t beat = {
				.note = rest,
				.duration = 0,
				.octave = 0, // octave doesn't matter, its a rest
			};
			play_note(beat, speaker);
		} else {
			// Note does not end, change nothing
		}
	}
	_delay_ms(BEAT_LENGTH * REST_FRACTION);
	
	return true;
}

int main(void)
{
    // Run initialisation functionality
	gpio_init();
	timer_init();

    while (1) 
    {

        // Wait for button press
		if (bit_is_clear(PIND, PIND2)) {
			// Play song until the end
			while(play_beat());
			
			// Turn off speakers once song is over
			beat_t beat = {
				.note = rest,
				.duration = 0,
				.octave = 0, // octave doesn't matter, its a rest
			};
			play_note(beat, 0);
			play_note(beat, 1);
		}
		
		
    }
}