#include <LiquidCrystal.h>

LiquidCrystal lcd(9, 10, 2, 3, 4, 5);

const int freqPotPin = A0;  
const int volPotPin = A1;
const int buzzerPin = 11;
const int nextButtonPin = 8;
const int menuButtonPin = 7;
const int saveButtonPin = 6;

const float minFreq = 87.0;
const float maxFreq = 108.0;
const int maxVolume = 255;
const int maxStations = 5;

struct Station {
  float frequency;
  char name[20];
  const char* rdsText;
};
Station stations[maxStations] = {
  {88, "Rock Lovers", "Rock Hits"},
  {90, "News 24/7", "Breaking News"},
  {95, "Electro Vibe", "EDM All Day"},
  {100, "Golden Era", "Hits of the 70s"},
  {105, "Relax FM", "Calm Music"}
};
int userStationIndex = 0;
int currentStationIndex = 0;
float selectedFrequency = 90.0;  

bool inMenu = false;
bool inManualFrequencyMode = false;  

enum EQSetting { NORMAL, BASS_BOOST, TREBLE_BOOST };
EQSetting currentEQ = NORMAL;

unsigned long lastDebounceTime = 0;
unsigned long debounceDelay = 300;
int lastButtonState = HIGH;

float lastDisplayedFrequency = -1;
int lastDisplayedVolume = -1;

void setup() {
  lcd.begin(20, 4);
  lcd.print("Custom Radio");
  delay(1000);
  lcd.clear();
  pinMode(buzzerPin, OUTPUT);
  pinMode(nextButtonPin, INPUT_PULLUP);
  pinMode(menuButtonPin, INPUT_PULLUP);
  pinMode(saveButtonPin, INPUT_PULLUP);
  Serial.begin(9600);
  Serial.println("Radio ready. Use buttons to switch stations and save new ones.");
}

void loop() {
  handleMenuButton();
  
  if (inMenu) {
    displayMenu();
    return;
  }

  handleNextStationButton();
  
  if (inManualFrequencyMode) {
    selectedFrequency = getSelectedFrequency();
  } else {
    selectedFrequency = stations[currentStationIndex].frequency;
  }

  int volume = applyEQ(getVolume());
  
  displayStationOrFrequencyInfo(selectedFrequency, volume);

  if (digitalRead(saveButtonPin) == LOW && userStationIndex < maxStations && inManualFrequencyMode) {
    saveUserStation(selectedFrequency);  
    delay(500);  
  }

  analogWrite(buzzerPin, volume);
  delay(500);
}

void handleMenuButton() {
  int buttonState = digitalRead(menuButtonPin);
  if (buttonState != lastButtonState) {
    lastDebounceTime = millis();
  }
  if ((millis() - lastDebounceTime) > debounceDelay) {
    if (buttonState == LOW) {
      inMenu = !inMenu; 
      if (inMenu) {
        lcd.clear();
        delay(300);
      } else {
        displayStationOrFrequencyInfo(selectedFrequency, applyEQ(getVolume())); // Обновить информацию при выходе
      }
    }
  }
  lastButtonState = buttonState;
}

void handleNextStationButton() {
  if (digitalRead(nextButtonPin) == LOW && !inManualFrequencyMode) {  
    delay(300);  
    currentStationIndex = (currentStationIndex + 1) % maxStations;
  }
}

float getSelectedFrequency() {
  int freqValue = analogRead(freqPotPin);
  return map(freqValue, 0, 1023, minFreq * 10, maxFreq * 10) / 10.0;
}

int getVolume() {
  int volValue = analogRead(volPotPin);
  return map(volValue, 0, 1023, 0, maxVolume);
}

void displayStationOrFrequencyInfo(float frequency, int volume) {
  if (lastDisplayedFrequency != frequency || lastDisplayedVolume != volume) {
    lcd.clear();
    bool isStationMatched = false;

    for (int i = 0; i < maxStations; i++) {
      if (abs(frequency - stations[i].frequency) < 0.1) {
        lcd.setCursor(0, 0);
        lcd.print("Station: ");
        lcd.print(stations[i].name);
        lcd.setCursor(0, 1);
        lcd.print("RDS: ");
        lcd.print(stations[i].rdsText);
        lcd.setCursor(0, 2);
        lcd.print("Volume: ");
        lcd.print(volume * 100 / maxVolume);
        isStationMatched = true;
        break;
      }
    }

    if (!isStationMatched) {
      lcd.setCursor(0, 0);
      lcd.print("Freq: ");
      lcd.print(frequency);
      lcd.print(" MHz");
      lcd.setCursor(0, 1);
      lcd.print("Volume: ");
      lcd.print(volume * 100 / maxVolume);
    }

    lastDisplayedFrequency = frequency;
    lastDisplayedVolume = volume;
  }
}

void saveUserStation(float frequency) {
  if (userStationIndex >= maxStations) {
    Serial.println("Max station limit reached.");
    return;
  }

  Serial.println("Enter name for saved station:");
  while (Serial.available() == 0) {}  
  String stationName = Serial.readStringUntil('\n');
  stationName.toCharArray(stations[userStationIndex].name, 20);
  stations[userStationIndex].frequency = frequency;
  stations[userStationIndex].rdsText = "User Defined";
  
  userStationIndex++;
  
  lcd.setCursor(0, 2);
  lcd.print("Station Saved!");
  Serial.print("Station Saved: ");
  Serial.println(frequency);
}

int applyEQ(int volume) {
  switch (currentEQ) {
    case BASS_BOOST:
      return min(volume + 50, maxVolume);
    case TREBLE_BOOST:
      return min(volume + 25, maxVolume);
    default:
      return volume;
  }
}

void displayMenu() {
  static bool lastMenuState = false;  

  if (inMenu != lastMenuState) { 
    lcd.clear();
    lastMenuState = inMenu;
  }

  lcd.setCursor(0, 0);
  lcd.print("Mode: ");
  lcd.print(inManualFrequencyMode ? "Manual Mode" : "Automatic Mode");  

  lcd.setCursor(0, 1);
  lcd.print("EQ: ");
  if (currentEQ == NORMAL) lcd.print("Normal");
  else if (currentEQ == BASS_BOOST) lcd.print("Bass Boost");
  else if (currentEQ == TREBLE_BOOST) lcd.print("Treble Boost");

  lcd.setCursor(0, 2);
  lcd.print("Change Mode: Save");
  lcd.setCursor(0, 3);
  lcd.print("Change EQ: Next");

  if (digitalRead(saveButtonPin) == LOW) {
    delay(300);  
    inManualFrequencyMode = !inManualFrequencyMode;  
  }

  if (digitalRead(nextButtonPin) == LOW) {
    delay(300);
    currentEQ = (EQSetting)((currentEQ + 1) % 3);
  }
}