/* Reaction game 
  19.5.2025. Đorđe Herceg

  Description:
  The goal is to wait for the sound and then press the key as quickly as possible.
  Reaction time is measured in milliseconds and shown on the screen.
  
  TODO:
  Make one LED flash while the player is waiting for the sound.
  Make another LED light up when the sound is heard. This is the cue for the player
  to push the button.
*/

// LCD I2C 16x2
// LiquidCrystal_I2C Library
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 16, 2);  // set the LCD address to 0x3F or 0x27 for a 16 chars and 2 line display


// BIPBox pin assignments
#define KEY1 39
#define KEY2 36
#define PIR 23
#define DHT 19
#define PHOTORESISTOR 34
#define POTENTIOMETER 35
#define LED1 16
#define LED2 17
#define LED3 18
#define BUZZER 33
#define SERVO 32

enum gameState { st_idle,
                 st_waiting,
                 st_starting,
                 st_reaction,
                 st_score };
enum gameState state = st_waiting;
unsigned long mils_start;
unsigned long mils_reaction;

// variables for keys
bool b1, b2, oldb1 = false, oldb2 = false, k1 = false, k2 = false;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("BIPBox Reaction Speed Test Game\nWhen the buzzer sounds and the LED lights up, press the left key.");

  // keys
  pinMode(KEY1, INPUT);  // Pullup resistors on the PCB, no need for INPUT_PULLUP
  pinMode(KEY2, INPUT);  // and pullup resistors don't exist on pins 36 and 39 anyway

  // buzzer
  pinMode(33, OUTPUT);
  tone(33, 800, 250);  // beep

  // Print a message to the LCD
  lcd.init();  // initialize the lcd
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Reaction Game");
  lcd.setCursor(0, 1);
  lcd.print("Wait for sound");

  pinMode(LED1, OUTPUT);
  pinMode(LED3, OUTPUT);
  digitalWrite(LED1, LOW);
  digitalWrite(LED3, LOW);
}

void loop() {
  // put your main code here, to run repeatedly:
  keyLoop();

  switch (state) {
    case st_idle:
      idleLoop();
      break;

    case st_waiting:
      waitingLoop();
      break;

    case st_starting:
      startingLoop();
      break;

    case st_reaction:
      reactionLoop();
      break;

    case st_score:
      scoreLoop();
      break;
  }
}

void keyLoop() {
  // ---- KEYS ----
  b1 = !digitalRead(KEY1);
  b2 = !digitalRead(KEY2);

  if (b1 && (b1 != oldb1))
    k1 = true;
  else
    k1 = false;
  if (b2 && (b2 != oldb2))
    k2 = true;
  else
    k2 = false;
  oldb1 = b1;
  oldb2 = b2;
}

bool readK1() {
  if (k1) {
    k1 = false;
    return true;
  } else {
    return false;
  }
}

void scoreLoop() {
  if (readK1()) {
    lcd.clear();
    digitalWrite(LED1, LOW);
    digitalWrite(LED3, LOW);

    delay(250);

    state = st_idle;
  }
}

void reactionLoop() {
  if (readK1()) {
    unsigned long mils_now = millis();
    unsigned long score = mils_now - mils_reaction;
    lcd.clear();
    lcd.print("Reaction time:");
    lcd.setCursor(2, 1);
    lcd.print(score);

    delay(750);
    lcd.setCursor(9, 1);
    lcd.print("Press A");
    state = st_score;
  }
}

void startingLoop() {
  static bool ledOn = false;
  unsigned long ledMils = millis();

  if (mils_start - millis() > 0) {
    if (readK1()) {
      // pressed the key too early - fail!
      lcd.clear();
      digitalWrite(LED1, LOW);  // turn off the LED
      lcd.print("Too early!");
      lcd.setCursor(0, 1);
      lcd.print("--FAIL--");
      tone(33, 300, 500);
      delay(500);
      state = st_score;
      return;
    } else {
      if (millis() - ledMils > 200){
        ledOn = !ledOn;
        digitalWrite(LED1, ledOn);
        ledMils = millis();
      }
      return;
    }
  }

  digitalWrite(LED1, LOW);
  digitalWrite(LED3, HIGH);
  tone(33, 800, 250);
  mils_reaction = millis();

  state = st_reaction;
}

void waitingLoop() {
  if (readK1()) {
    lcd.clear();
    lcd.print("Press A on sound!");

    delay(250);    // let the user release the key
    mils_start = millis() + random(1000, 5000);  // pick the time 1s to 5s from current
    state = st_starting;
  }
}

void idleLoop() {
  lcd.clear();
  lcd.print("Push A to start");

  state = st_waiting;
}