// === Airplane Seat Booking System ===
// Final version with cleaned structure, no ternary operators

int ledMat_first[2][2] = {
  {22, 23},
  {26, 27}
};

int ledMat_eco[4][3] = {
  {30, 31, 32},
  {34, 35, 36},
  {38, 39, 40},
  {42, 43, 44}
};

bool ledStat_first[2][2];
bool ledStat_eco[4][3];

const unsigned long BLINK_INTERVAL = 500;
unsigned long lastBlinkTime = 0;
bool blinkState = false;

String inputString = "";
bool classSelected = false;
bool rowSelected = false;
bool colSelected = false;
bool confirmed = false;

int selectedClass = -1;
int selectedRow = -1;
int selectedCol = -1;

bool classPromptPrinted = false;
bool rowPromptPrinted = false;
bool colPromptPrinted = false;
bool confirmPromptPrinted = false;

void setup() {
  Serial.begin(9600);

  for (int i = 0; i < 2; i++)
    for (int j = 0; j < 2; j++) {
      pinMode(ledMat_first[i][j], OUTPUT);
      ledStat_first[i][j] = false;
    }

  for (int i = 0; i < 4; i++)
    for (int j = 0; j < 3; j++) {
      pinMode(ledMat_eco[i][j], OUTPUT);
      ledStat_eco[i][j] = false;
    }

  Serial.println("Welcome to the seat booking system.");
}

void loop() {
  updateLEDs();

  if (!classSelected) {
    chooseClass();
  } else if (!rowSelected) {
    chooseRow();
  } else if (!colSelected) {
    chooseColumn();
  } else if (!confirmed) {
    confirmSeat();
  }
}

// === Blink logic without delay ===
void updateBlinkState() {
  unsigned long currentMillis = millis();
  if (currentMillis - lastBlinkTime >= BLINK_INTERVAL) {
    lastBlinkTime = currentMillis;
    blinkState = !blinkState;
  }
}

// === Update LED based on state ===
void updateLEDs() {
  updateBlinkState();

  for (int i = 0; i < 2; i++)
    for (int j = 0; j < 2; j++)
      digitalWrite(ledMat_first[i][j], LOW);

  for (int i = 0; i < 4; i++)
    for (int j = 0; j < 3; j++)
      digitalWrite(ledMat_eco[i][j], LOW);

  if (!classSelected) {
    for (int i = 0; i < 2; i++)
      for (int j = 0; j < 2; j++) {
        int pin = ledMat_first[i][j];
        if (ledStat_first[i][j]) digitalWrite(pin, HIGH);
        else digitalWrite(pin, blinkState ? HIGH : LOW);
      }
    for (int i = 0; i < 4; i++)
      for (int j = 0; j < 3; j++) {
        int pin = ledMat_eco[i][j];
        if (ledStat_eco[i][j]) digitalWrite(pin, HIGH);
        else digitalWrite(pin, blinkState ? HIGH : LOW);
      }
    return;
  }

  if (!rowSelected) {
    if (selectedClass == 0) {
      for (int i = 0; i < 2; i++)
        for (int j = 0; j < 2; j++) {
          int pin = ledMat_first[i][j];
          if (ledStat_first[i][j]) digitalWrite(pin, HIGH);
          else digitalWrite(pin, blinkState ? HIGH : LOW);
        }
    } else {
      for (int i = 0; i < 4; i++)
        for (int j = 0; j < 3; j++) {
          int pin = ledMat_eco[i][j];
          if (ledStat_eco[i][j]) digitalWrite(pin, HIGH);
          else digitalWrite(pin, blinkState ? HIGH : LOW);
        }
    }
    return;
  }

  if (selectedClass == 0) {
    for (int j = 0; j < 2; j++) {
      int pin = ledMat_first[selectedRow][j];
      if (ledStat_first[selectedRow][j]) digitalWrite(pin, HIGH);
      else digitalWrite(pin, blinkState ? HIGH : LOW);
    }
  } else {
    for (int j = 0; j < 3; j++) {
      int pin = ledMat_eco[selectedRow][j];
      if (ledStat_eco[selectedRow][j]) digitalWrite(pin, HIGH);
      else digitalWrite(pin, blinkState ? HIGH : LOW);
    }
  }
}

// === State Checks ===
bool isFirstClassFull() {
  for (int i = 0; i < 2; i++)
    for (int j = 0; j < 2; j++)
      if (!ledStat_first[i][j]) return false;
  return true;
}

bool isEconomyClassFull() {
  for (int i = 0; i < 4; i++)
    for (int j = 0; j < 3; j++)
      if (!ledStat_eco[i][j]) return false;
  return true;
}

bool isRowFull(int row) {
  if (selectedClass == 0) {
    for (int j = 0; j < 2; j++)
      if (!ledStat_first[row][j]) return false;
  } else {
    for (int j = 0; j < 3; j++)
      if (!ledStat_eco[row][j]) return false;
  }
  return true;
}

void resetAllSeats() {
  for (int i = 0; i < 2; i++)
    for (int j = 0; j < 2; j++)
      ledStat_first[i][j] = false;
  for (int i = 0; i < 4; i++)
    for (int j = 0; j < 3; j++)
      ledStat_eco[i][j] = false;

  Serial.println("All seats are now reset.");
  classSelected = rowSelected = colSelected = confirmed = false;
  selectedClass = selectedRow = selectedCol = -1;
  classPromptPrinted = rowPromptPrinted = colPromptPrinted = confirmPromptPrinted = false;
}

// === Class Selection ===
void chooseClass() {
  bool firstFull = isFirstClassFull();
  bool ecoFull = isEconomyClassFull();

  if (firstFull && ecoFull) {
    resetAllSeats();
    return;
  }

  if (!classPromptPrinted) {
    Serial.println("\nSelect seat class:");
    if (!firstFull) Serial.println("Enter 1 for First Class");
    if (!ecoFull) Serial.println("Enter 2 for Economy Class");
    Serial.print("Input: ");
    classPromptPrinted = true;
  }

  while (Serial.available()) {
    char inChar = (char)Serial.read();
    if (inChar == '\n' || inChar == '\r') {
      inputString.trim();
      if (inputString == "1" && !firstFull) {
        selectedClass = 0;
        classSelected = true;
        Serial.println("First Class selected.");
      } else if (inputString == "2" && !ecoFull) {
        selectedClass = 1;
        classSelected = true;
        Serial.println("Economy Class selected.");
      } else {
        Serial.println("Invalid input or class full. Try again.");
      }
      inputString = "";
      classPromptPrinted = false;
    } else {
      inputString += inChar;
    }
  }
}

// === Row Selection ===
void chooseRow() {
  int maxRow = (selectedClass == 0) ? 2 : 4;

  if (!rowPromptPrinted) {
    Serial.print("Enter row number (1 to ");
    Serial.print(maxRow);
    Serial.println("): ");
    rowPromptPrinted = true;
  }

  while (Serial.available()) {
    char inChar = (char)Serial.read();
    if (inChar == '\n' || inChar == '\r') {
      inputString.trim();
      int rowNum = inputString.toInt();
      if (rowNum >= 1 && rowNum <= maxRow) {
        if (!isRowFull(rowNum - 1)) {
          selectedRow = rowNum - 1;
          rowSelected = true;
          Serial.print("Row ");
          Serial.print(rowNum);
          Serial.println(" selected.");
        } else {
          Serial.println("Row is full. Please select another.");
        }
      } else {
        Serial.println("Invalid row number. Try again.");
      }
      inputString = "";
      rowPromptPrinted = false;
    } else {
      inputString += inChar;
    }
  }
}

// === Column Selection ===
void chooseColumn() {
  int maxCol = (selectedClass == 0) ? 2 : 3;

  if (!colPromptPrinted) {
    Serial.print("Enter seat number in row (1 to ");
    Serial.print(maxCol);
    Serial.println("): ");
    colPromptPrinted = true;
  }

  while (Serial.available()) {
    char inChar = (char)Serial.read();
    if (inChar == '\n' || inChar == '\r') {
      inputString.trim();
      int colNum = inputString.toInt();
      if (colNum >= 1 && colNum <= maxCol) {
        bool occupied = false;
        if (selectedClass == 0) occupied = ledStat_first[selectedRow][colNum - 1];
        else occupied = ledStat_eco[selectedRow][colNum - 1];

        if (!occupied) {
          selectedCol = colNum - 1;
          colSelected = true;
          Serial.print("Seat ");
          Serial.print(colNum);
          Serial.println(" selected.");
        } else {
          Serial.println("Seat is already occupied. Select another.");
        }
      } else {
        Serial.println("Invalid seat number. Try again.");
      }
      inputString = "";
      colPromptPrinted = false;
    } else {
      inputString += inChar;
    }
  }
}

// === Seat Confirmation ===
void confirmSeat() {
  if (!confirmPromptPrinted) {
    Serial.print("Confirm seat - Class: ");
    if (selectedClass == 0) Serial.print("First");
    else Serial.print("Economy");
    Serial.print(", Row: ");
    Serial.print(selectedRow + 1);
    Serial.print(", Seat: ");
    Serial.print(selectedCol + 1);
    Serial.println(" ? (Y/N): ");
    confirmPromptPrinted = true;
  }

  while (Serial.available()) {
    char inChar = (char)Serial.read();
    if (inChar == '\n' || inChar == '\r') {
      inputString.trim();
      if (inputString.equalsIgnoreCase("Y")) {
        if (selectedClass == 0)
          ledStat_first[selectedRow][selectedCol] = true;
        else
          ledStat_eco[selectedRow][selectedCol] = true;

        Serial.println("Seat confirmed. Thank you!");
        classSelected = rowSelected = colSelected = confirmed = false;
        selectedClass = selectedRow = selectedCol = -1;
        confirmPromptPrinted = false;
      } else {
        Serial.println("Seat cancelled. Restarting row selection.");
        rowSelected = colSelected = confirmed = false;
        confirmPromptPrinted = false;
      }
      inputString = "";
    } else {
      inputString += inChar;
    }
  }
}