#include <LiquidCrystal.h>

#define vol A1 // INPUT / Reads Voltage to determine Volumne.

#define r1 A2 // OUTPUT / mode 1 indicator light
#define r2 A3 // OUTPUT / mode 2 indicator light
#define r3 A4 // OUTPUT / mode 3 indicator light
#define r4 A5 // OUTPUT / mode 4 indicator light

const int delta = 4000; // change of range by mode.
const int delta_min = 100; // change of interval inside mode oscillation.

const int buzzer = 3; // OUTPUT / voltage to speaker and volumne determination.
const int SW_pin = 2; // INPUT / used for mute button

LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

enum keyPadButton{
RIGHT = 0,
LEFT = 505,
UP = 144,
DOWN = 329,
SELECT = 742,
NONE = 1023
};

enum joystick{
  BUTTON_DOWN,
  BUTTON_UP,
};

joystick state = BUTTON_UP;

void setup() {
  joySetup();
  keypadSetup();
}

int tempo = 1000 / 4; // 4 notes a second
int mode = 2; // starts in mode 2
int c = 0; // concurrent counter of change in delta min
int d = 1; // direction of counter
int muted = 1; // boolean if muted

void loop() {
  noTone(buzzer); // turns off the tone at buzzer

  processJoystick();
  processKeyPress(getKeyPressed());
  manageLights();

  int lroof = delta * (mode + 1); // calculates modes roof value
  int lfloor = delta * mode; // calculates modes floor value

 if (muted == 0) {
  tone(buzzer, lfloor + c); /

  if (d == 1) {
    c += delta_min;
    if (c > (lroof - lfloor)) {
      d = -1;
    }
  } else {
    c -= delta_min;
    if (c < 0) {
      d = 1;
    }
  }
 } else {
  lcd.setCursor(4, 0);
  lcd.print("[MUTED]");
 }

  lcd.setCursor(0, 1);
  lcd.print("FREQ=");
  lcd.print(lfloor + c);
  lcd.print(" HZ");

  delay(tempo);
  lcd.clear();
}

void manageLights() {
  analogWrite(r1, 0);
  analogWrite(r2, 0);
  analogWrite(r3, 0);
  analogWrite(r4, 0);

  if (muted == 0) {
  if (mode == 1) {
    analogWrite(r1, 255);
  } else if (mode == 2) {
    analogWrite(r2, 255);
  } else if (mode == 3) {
    analogWrite(r3, 255);
  } else if (mode == 4) {
    analogWrite(r4, 255);
  }
  }
}

void keypadSetup() {
  pinMode(r1, OUTPUT);
  pinMode(r2, OUTPUT);
  pinMode(r3, OUTPUT);
  pinMode(r4, OUTPUT);
  lcd.begin(16, 2);
}

int prevB = 0; // Previous Button State
joystick psw = BUTTON_UP; // Previous Stick State

void processKeyPress(int keyPressed) {

  digitalWrite(buzzer, HIGH);
  lcd.setCursor(0, 0);
  lcd.print("Vol=");
  int v = analogRead(vol);
  v = (v / 10.24);
  lcd.print(v);
  lcd.print("%");

  lcd.setCursor(0, 1);

  if (psw == BUTTON_UP && state == BUTTON_DOWN) {
      if (muted == 1) {
        muted = 0;
      } else {
        muted = 1;
      }
  }else if (keyPressed > NONE-2 && keyPressed < NONE+2 ){
  } else if (keyPressed > SELECT-2 && keyPressed < SELECT+2 ) {
  } else if (keyPressed > RIGHT-2 && keyPressed < RIGHT+2 ) {
    mode = 4;
  } else if (keyPressed > LEFT-2 && keyPressed < LEFT+2 ) {
    mode = 2;
  } else if (keyPressed > UP-2 && keyPressed < UP+2 ) {
    mode = 3;
  } else if (keyPressed > DOWN-2 && keyPressed < DOWN+2 ) {
    mode = 1;
  }

  prevB = keyPressed;
  psw = state;
}

int getKeyPressed() {
  return analogRead(0);
}

void joySetup() {
  pinMode(vol, INPUT);
  pinMode(SW_pin, INPUT);
  digitalWrite(SW_pin, HIGH);
}

int getJoystickState() {
  int s = digitalRead(SW_pin);
  return s;
}

void processJoystickState(int joyState) {
  if (joyState == 0) {
    state = BUTTON_DOWN;
  } else {
    state = BUTTON_UP;
  }
}

void processJoystick() {
  processJoystickState(getJoystickState());
}