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

#define DEBOUNCE_COUNT 100
#define BOMB_COUNTDOWN_TIME 65

unsigned char displaydata[8] = {' ', ' ', ' ', ' ', ' ', ' ', ' ', ' '}, adress;
uint8_t debounce[8] = {0,0,0,0,0,0,0,0}; //input debounce 
uint8_t debounced = 0;



void display_time(int time);
void display_clear(void);

void display_update(void);
void display_send_one(uint8_t address, unsigned char data);
void shift_send(unsigned char data);

void mp3_play(uint8_t mp3file);
void timer_start(void);
void timer_speed_up(void);
void timer_pause(void);

void motor_step_forward(void);
void motor_step_back(void);

uint8_t radio_signal(void);

enum{
    BOMB_DISARMED,
    BOMB_ARMED,
    BOMB_DEFUSED,
    BOMB_EXPLODED
} bombState;

//functions for updating the bomb in a given state
void bomb_logic_disarmed(void);
void bomb_logic_armed(void); //  <-- this will be unique for each bomb
void bomb_logic_defused(void);
void bomb_logic_exploded(void);

//functions for ENTERING a state
void bomb_logic_disarm(void);
void bomb_logic_arm(void);
void bomb_logic_defuse(void);
void bomb_logic_explode(void);

//return_data_type function(input_data_type    input_variable_local_name)
//void display_send_one(unsigned char data);
//PORTD |= 1<<0; //(set D.0) Shifts a one zero steps left
//PORTD &= ~(1<<0); //(reset D.0) Creates a byte consisting of ones, shifts a zero 0 steps left

void display_send_one(uint8_t address, unsigned char data) //Send the character 'data' to the display position defined in 'adress'
{
	address = 7-address;
	PORTD &= 0b10000000;  //Clear all data pins
	PORTA &= 0b11111100;  //Clear address
	PORTA |= (address & 0b00000011); //set address
	PORTD |= (data & 0b01111111); //Set the 7 bit ASCII output for one character
	_delay_us(5);
	if (address & 0b0000100)
	{
		PORTA &= 0b11111011; //Clock the write pin
		_delay_us(5);
		PORTA |= 0b00000100;
	}
	else
	{
		PORTA &= 0b11110111; //Clock the write pin
		_delay_us(5);
		PORTA |= 0b00001000;
	}
	_delay_us(5);
}

void display_update(void) //Send the array displaydata to the display, setting the adress variable to the correct value for each char.
{
	for (unsigned char i = 0; i < 8; i++)
	{
		display_send_one(i, displaydata[i]);
	}
}


void mp3_play(uint8_t mp3file)
{
	mp3file &= 0b00000111;
	DDRB |= mp3file;
	_delay_ms(40);
	DDRB &=0b11111000;
}


void display_clear(void){
	displaydata[0] = ' '; displaydata[1] = ' '; displaydata[2] = ' '; displaydata[3] = ' ';
	displaydata[4] = ' '; displaydata[5] = ' '; displaydata[6] = ' '; displaydata[7] = ' ';
	display_update();
}

void display_time(int time) //displays the 'time' given in seconds as MM:SS on the LCD
{ 
	uint8_t current_digit = 0;

	//static part of display
	displaydata[0] = ' ';
	displaydata[4] = ':';
	displaydata[7] = ' ';

	//limit to 60:00
	if(time > 3600){
		time = 3600;
	}

	//'-' sign for negative time?
	if(time < 0){
		time *= -1;
		displaydata[1] = '-';
	}else{
		displaydata[1] = ' ';
	}

	//rest of the time
	current_digit = 0;
	while(time>=600){ //tens of minutes
		current_digit += 1;
		time -= 600;
	}
	displaydata[2] = current_digit + '0';

	current_digit = 0;
	while(time>=60){ //minutes
		current_digit += 1;
		time -= 60;
	}
	displaydata[3] = current_digit + '0';

	current_digit = 0;
	while(time>=10){ //tens of seconds
		current_digit += 1;
		time -= 10;
	}
	displaydata[5] = current_digit + '0';


	displaydata[6] = time + '0';

	display_update();	
}

void timer_start(void){
	//Set up Timer1
	TCCR1B |= (1 << CS10) | (1 << CS12) | (1 << WGM12); //prescaler 1024
	TCNT1 = 0; //zero out timer
	//TIMSK1 |= (1 << OCIE1A); //enable output compare A
	OCR1A = 4040; //output compare A will trigger at approx 1Hz. Callibrated at 5V
	TIMSK1 |= (1 << OCIE1A);
}

void timer_speed_up(void){
	TCNT1 = 1700; //set a timer a safe distance away from the trigger point.
	OCR1A = 2020; //output compare A will triger at approx 2Hz. Callibrated at 5V
}

void timer_pause(void){
	TCCR1B = 0; //stop timer
}


void motor_step_forward(void){
	PORTD &= 0xF0; //PRE-enable zero
	PORTB &= 0b01111111; //enable motor drive
	PORTD &= 0xF0; _delay_us(50); PORTD |= 0b00000001; _delay_us(2000);
	PORTD &= 0xF0; _delay_us(50); PORTD |= 0b00000100; _delay_us(2000);
	PORTD &= 0xF0; _delay_us(50); PORTD |= 0b00000010; _delay_us(2000);
	PORTD &= 0xF0; _delay_us(50); PORTD |= 0b00001000; _delay_us(2000);
	PORTB |= 0b10000000; //disable motor drive
}

void motor_step_back(void){
	PORTD &= 0xF0; //PRE-enable zero
	PORTB &= 0b01111111; //enable motor drive
	PORTD &= 0xF0; _delay_us(50); PORTD |= 0b00001000; _delay_us(2000);
	PORTD &= 0xF0; _delay_us(50); PORTD |= 0b00000010; _delay_us(2000);
	PORTD &= 0xF0; _delay_us(50); PORTD |= 0b00000100; _delay_us(2000);
	PORTD &= 0xF0; _delay_us(50); PORTD |= 0b00000001; _delay_us(2000);
	PORTB |= 0b10000000; //disable motor drive
}


uint8_t radio_signal(void){
	return (PINB & 0b01000000);
}

//BOMB LOGIC 
int16_t countdown = 65;
uint8_t armed = 0;

int main(void)
{
	DDRA = 0b00001111;
	DDRB = 0b10000000;
	DDRC = 0b10111111;
	DDRD = 0b11111111;
/*
D0-D6 data
D7 CU
A0-A1 adress
A2 /Write0
A3 /Write1

D0-D3 doubles as motor drive pins

C0-C5 inputs, C7 input/button
B0, B1, B2 MP3 playback triggers
B3 spare MP3 trigger
B4-B5 NMOS outputs
B6 Radio remote input
B7 enable motor drive
*/
	PORTA |= 0b00000110;
	PORTB = 0b10000000;
	PORTC = 0b10111111;
	PORTD = 0;
	_delay_us(500);
	PORTA &= 0b11111011; //Clock the write pin
	_delay_us(500);
	PORTA |= 0b00000100;
	_delay_us(500);
	PORTA &= 0b11110111; //Clock the write pin
	_delay_us(500);
	PORTA |= 0b00001000;
	_delay_us(500);
	PORTD |= 0b10000000;

	timer_start();
	display_clear();
	
	sei(); //interrupts enable!

	while(1)
	{
		if(radio_signal()){
			if(bombState == BOMB_DISARMED){bomb_logic_arm();}
		}else{
			if(bombState != BOMB_DISARMED){bomb_logic_disarm();}	
		}
		
		//input debouncing
		for(int i=0; i<8; i++){
			if(PINC & 1<<i){
				if(debounce[i] < DEBOUNCE_COUNT ){
					debounce[i]+=1;
				}
			}else{
				if(debounce[i] > 0){
					debounce[i]-=1;
				}
			}
			if(debounce[i] == DEBOUNCE_COUNT){
				debounced |= 1<<i;
			}
			if(debounce[i] == 0){
				debounced &= ~(1<<i);
			}
		}

		switch(bombState){
			case BOMB_DISARMED:
				bomb_logic_disarmed();
				break;

			case BOMB_ARMED:
				bomb_logic_armed();
				break;

			case BOMB_DEFUSED:
				bomb_logic_defused();
				break;

			case BOMB_EXPLODED:
				bomb_logic_exploded();
				break;
		}
	}
	return 0;
}

void bomb_logic_disarm(void){
	bombState = BOMB_DISARMED;
	timer_pause();
}

void bomb_logic_disarmed(void){
	displaydata[0] = 'D'; displaydata[1] = 'I'; displaydata[2] = 'S'; displaydata[3] = 'A';
	displaydata[4] = 'R'; displaydata[5] = 'M'; displaydata[6] = 'E'; displaydata[7] = 'D';
	//When disarmed, show the wire status by BIG/SMALL letters
	for(int i=0; i<8; i++){
		if(debounced >> i & 0x01){
			displaydata[i] += 32;
		}
	}
	display_update();
}

void bomb_logic_arm(void){
	bombState = BOMB_ARMED;
	countdown = BOMB_COUNTDOWN_TIME;
	display_time(countdown);
	mp3_play(1);
	timer_start();
}

void bomb_logic_armed(void){
	if(countdown == 0){
		bomb_logic_explode();
	}

	if(debounced & 0b10000000){
		bomb_logic_defuse();
	}

	if(debounced & 0b00100000){
		bomb_logic_explode();
	}
}


void bomb_logic_defuse(void){
	bombState = BOMB_DEFUSED;
	timer_pause();
	displaydata[1] = '[';
	displaydata[7] = ']';
	display_update();
}

void bomb_logic_defused(void){
	//not much to do here
}

void bomb_logic_explode(void){
	bombState = BOMB_EXPLODED;
	timer_pause();
	mp3_play(2);
	displaydata[0] = ' '; displaydata[1] = ' '; displaydata[2] = 'B'; displaydata[3] = 'O';
	displaydata[4] = 'O'; displaydata[5] = 'M'; displaydata[6] = ' '; displaydata[7] = ' ';
	display_update();
}

void bomb_logic_exploded(void){
	//BOOM animation.
	//Because of rand(), this takes a LOT of FLASH MEMORY
	//Remove if in need of more PROGRAM space
	for(int i=2; i<6; i++){
		if(rand() > 0x3FFF){
			displaydata[i] |= 0b00100000;
		}else{
			displaydata[i] &= 0b11011111;
		}
	}
	display_update();
	_delay_ms(100);
	//not much to do here
	//maybe blink an LED or something
}

uint8_t half_second = 0;
ISR(TIMER1_COMPA_vect){
	half_second ^= 0x01; //will be true every other half-second
	if(half_second){
		if(countdown>0){countdown -= 1;}
		display_time(countdown);
		if(countdown < 10){mp3_play(1);}
	}else{
		display_send_one(4, ' ');
	}
}