//Clock source & fuse bits:
//Internal oscillator 8Mhz: CKSEL3..1=0010 SUT1..0=00
//External oscillator from board: CKSEL3..1=0000 SUT1..0=00
//Low Power Crystal Oscillator: CKSEL3..1=1111 SUT1..0=11

#include<avr/io.h>
#include<avr/interrupt.h>
#include <avr/eeprom.h>
#include"lcd.h"
#include"stdlib.h"

//timeout values for each task
#define t1 250
#define t2 125
#define t3 1

//the three task subroutines
void task1(void); //blinks LED0 at 4 or 8 Hz
void task2(void); //blinks LED1 at 8 Hz
void task3(void); //detect button and modify task1 rate

void initialize(void); //all the usual MCU stuff

volatile unsigned char time1, time2, time3; //timeout counters
volatile unsigned char led; //light states
volatile unsigned char state = 0;
volatile unsigned char time4;
volatile unsigned int x;
volatile short reactionTime = 0;
long i;
int flag = 0;
uint16_t EEMEM EEPROM;
volatile short highScore;

volatile unsigned char task;
volatile unsigned char task5;

volatile char seconds;
volatile char milisec;

char buffer[7];
char buffer2[7];

//randomnumber generation
volatile double randomNumber;
volatile double low;
volatile double high;

unsigned char tsk2m;
uint16_t eeprom_read_word(const uint16_t *addr);
void eeprom_write_word(uint16_t *addr, uint16_t value);

//timer0 compare Interrupt Service Routine (ISR)
ISR(TIMER1_COMPA_vect) {
    //decrement the three times if they are not already zero
    if (time1 > 0)
        --time1;
    if (time2 > 0)
        --time2;
    if (time3 > 0)
        --time3;
    if (time4 > 0)
        --time4;
}

ISR(PCINT3_vect) {

    if (task == 0b01111111) {
        state = 0;

    }
    else if (task == 0b11111110){
        if (state == 0)
            state = 1;
        else if (state == 2)
            state = 3;
        else if (state > 3)
            state = 0;

    }

}

//entry point and task scheduler loop
int main(void) {
    initialize();

    //main task scheduler loop
    while (1) {

        switch (state) {
        case (0):
            if (time1 == 0)
                task1();
            task = PIND;
            break;
        case (1):
            //randomNumber = rand()/RAND_MAX;
            //randomNumber =  low + randomNumber * (high - low);
            task2();
            flag = 0;
            state = 2;
            if (PIND == 0b11111110) {
                lcd_clrscr();
                lcd_puts("Stop cheating \n");
                lcd_puts("you bastard");
                state = 4;
            }

            break;

        case (2):

            if (time3 == 0) {
                reactionTime++;
                task3();
            }
            seconds = reactionTime/1000;
            milisec = reactionTime%1000;
            break;

        case (3):

            //      highScore = eeprom_read_word(&EEPROM);
            //      if (reactionTime < highScore) {
            //                  eeprom_write_word(&EEPROM, reactionTime);
            //      }
            //      highScore = eeprom_read_word(&EEPROM);

        //Convert integer to string type
            itoa(highScore, buffer, 10);
            itoa(seconds, buffer2, 10);


            if (flag == 0) {
                lcd_clrscr();
                lcd_puts("Your score:");
                lcd_puts(buffer2);
                lcd_puts("\nHigh score:");
                lcd_puts(buffer);
                flag = 1;
                reactionTime = 0;
            }

            task = PIND;
            break;

        default:
            break;
        }

    }

}

//task 1
void task1(void) {
    time1 = t1; //reset the task timer
    led = led ^ 0xff; //toggle the zero's
    PORTB = led;
}

//task 2
void task2(void) {
    time1 = t1; //reset the task time
    x = 0; //reset the counter
    PORTB = 0xff; //turn LEDs off

    while (x <= 6) //time delay
    {
        if (time1 == 0) {
            x++;
            time1 = t1;
        }
    }

}
//task 3
void task3(void) {
    time3 = t3;         //reset time
    PORTB &= 0x00;      //turn all LEDs on

}

//set it all up
void initialize(void) {

    //set up the ports
    DDRD = 0x00; //PORTC is an input
    DDRB = 0xff; //PORTB is an ouput

    //set timer0
    TCCR1A = 0b00000000; //CTC mode no PWM, the most significant 6 bits do not matter for this lab
    TCCR1B = 0b00001011; //prescaler 64
    TIMSK1 = 0b00000010; //enable Output Compare A Match interrupt
    OCR1A = 250; //set the compare register to 250 clock ticks -> Output Compare A Match interrupt occurs with 1KHz frequency

    PCICR = 0b00001000; //enable Pin Change Interrupt PCIE3
    PCMSK3 = 0b10000001; //enable I/O pin 0 this looks at switch 0.
    EICRA = 0b00000010;
    /* initialize display, cursor off */
    lcd_init(LCD_DISP_ON);

    //eeprom_write_word(&EEPROM, 10);

    //init the LED status (all off)
    led = 0xff;

    //init the task timers
    time1 = t1;
    time2 = t2;
    time3 = t3;
    time4 = t1;

    //initialize randomNumber
    randomNumber = 0;
    low = 8;
    high = 15;

    // LCD
    /* clear display and home cursor */
    lcd_clrscr();

    task = 0;
    task5 = 0;

    //crank up the ISRs
    sei();
}