int speakerPin = 9;
int potPin = A2;
int buttonPin = 2;
int led1 = 3;
int led2 = 4;
int led3 = 5;
int led4 = 6;

int switchState = LOW;
boolean buttonClear = true;
int songChoice;
int ledPattern = true;

const int beatLength = 50; 


void playTone(int tone, int duration) {
for (long i = 0; i < duration * 1000L; i += tone * 2) {
digitalWrite(speakerPin, HIGH);
delayMicroseconds(tone);
digitalWrite(speakerPin, LOW);
delayMicroseconds(tone);
}
}

void playNote(char note, int duration, boolean sharp) {
char names[] = { 'c', 'd', 'e', 'f', 'g', 'a', 'b', 'C', 'D', 'E', 'F', 'G', 'A', 'B' };
int tones[] = { 1915, 1700, 1519, 1432, 1275, 1136, 1014, 956, 851, 758, 716, 636, 568, 506 };


char names_sharp[] = { 'c', 'd', 'f', 'g', 'a', 'C', 'D', 'F', 'G', 'A' };
int tones_sharp[] = { 1804, 1607, 1351, 1204, 1073, 902, 804, 676, 602, 536 };


if (sharp == false) {
for (int i = 0; i < 14; i++) {
if (names[i] == note) {
playTone(tones[i], duration);
}
}
} else {
for (int i = 0; i < 10; i++) {
if (names_sharp[i] == note) {
playTone(tones_sharp[i], duration);
}
}
}
}

//Introdurre un pulsante
void updateSwitchState() {
int val = digitalRead(buttonPin);
if (val == HIGH) {
buttonClear = true;
} else {
if (buttonClear == true) {
if (switchState == LOW) {
switchState = HIGH;
} else {
switchState = LOW;
}
buttonClear = false;
}
}
}

// Far ballare i led a ritmo di musica
void alternateLeds() {
if (ledPattern == true) {
digitalWrite(led1, LOW);
digitalWrite(led2, HIGH);
digitalWrite(led3, LOW);
digitalWrite(led4, HIGH);
ledPattern = false;
} else {
digitalWrite(led1, HIGH);
digitalWrite(led2, LOW);
digitalWrite(led3, HIGH);
digitalWrite(led4, LOW);
ledPattern = true;
}
}

void parseTune(char notes[], int beatLength, boolean loopSong) {
boolean play = true;


for (int i = 0; notes[i] != '.' && play == true; i++) { 
updateSwitchState();
if (switchState == LOW) { 
play = false;
} else {
if (notes[i] == ',') { 


char len[3];
int count = 0;
while (notes[i+1] >= '0' && notes[i+1] <= '9' && count < 2) {
len[count] = notes[i+1];
count++;
i++;
}
len[count] = '\0';
int duration = atoi(len);

delay(duration * beatLength); 
} else { 
alternateLeds(); 
char note = notes[i];
boolean sharp;


if (notes[i+1] == '#') {
i++;
sharp = true;
} else {
sharp = false;
}


char len[3];
int count = 0;
while (notes[i+1] >= '0' && notes[i+1] <= '9' && count < 2) {
len[count] = notes[i+1];
count++;
i++;
}
len[count] = '\0';
int duration = atoi(len);

playNote(note, duration * beatLength, sharp);
}

delay(beatLength / 2); 
}
}

if (loopSong == false) {
switchState = LOW;
}
}

void playTune (int tune) {
if (tune == 1) { // Jingle Bells
char notes[] = "b4b4b8b4b4b8b4D4g6a2b12,4C4C4C6C2C4b4b4b2b2b4a4a4b4a8D8b4b4b8b4b4b8b4D4g6a2b12,4,C4C4C6C2C4b4b4b2b2D4D4C4a4g12,8.";
parseTune(notes, beatLength, false);
} else if (tune == 2) { // The Holly and the Ivy
char notes[] = "g4g2g2g4E4D4b6g2g2g2g4E4D8D2C2b2a2g4b2b2e2e2d4g2a2b2C2b4a4g8,8.";
parseTune(notes, beatLength * 1.50, false);
} else if (tune == 3) { // we wish you a merry christmas
char notes[] = "d4g4g2a2g2f#2e4c4e4a4a2b2a2g2f#4d4f#4b4b2C2b2a2g4e4d2d2e4a4f#4g8,8.";
parseTune(notes, beatLength * 1.25, false);
} else if (tune == 4) { // Deck the Halls
char notes[] = "D6C2b4a4g4a4b4g4a2b2C2a2b6a2g4f#4g6,2D6C2b4a4g4a4b4g4a2b2C2a2b6a2g4f#4g6,2a6b2C4a4b6C2D4a4b2C#2D4E2F#2G4F#4E4D6,2D6C2b4a4g4a4b4g4E2E2E2E2D6C2b4a4g8,8.";
parseTune(notes, beatLength, false);
}
}

void setup() {
pinMode(speakerPin, OUTPUT);
pinMode(buttonPin, INPUT);
pinMode(led1, OUTPUT);
pinMode(led2, OUTPUT);
pinMode(led3, OUTPUT);
pinMode(led4, OUTPUT);
}

void loop() {

//Qui scegliamo gli intervalli dei valori che ci fornirà il potenziometro
int val = analogRead(potPin);
if (val < 388) {
songChoice = 1;
digitalWrite(led1, HIGH);
digitalWrite(led2, LOW);
digitalWrite(led3, LOW);
digitalWrite(led4, LOW);
} else if (val < 512) {
songChoice = 2;
digitalWrite(led1, LOW);
digitalWrite(led2, HIGH);
digitalWrite(led3, LOW);
digitalWrite(led4, LOW);
} else if (val < 645) {
songChoice = 3;
digitalWrite(led1, LOW);
digitalWrite(led2, LOW);
digitalWrite(led3, HIGH);
digitalWrite(led4, LOW);
} else {
songChoice = 4;
digitalWrite(led1, LOW);
digitalWrite(led2, LOW);
digitalWrite(led3, LOW);
digitalWrite(led4, HIGH);
}

updateSwitchState();
if (switchState == HIGH) {
playTune(songChoice);
}
}