#include <Adafruit_Fingerprint.h>
#include <Wire.h>

#define FINGERPRINT_SENSOR_PIN 2    // GPIO pin for fingerprint sensor
#define BUTTON1_PIN 12              // Push button 1: Candidate Registration
#define BUTTON2_PIN 13              // Push button 2: Voter Registration
#define BUTTON3_PIN 14              // Push button 3: Voter Login
#define BUTTON4_PIN 15              // Push button 4: Voting
#define LED_PIN 16                  // LED Pin to indicate status

#define MAX_CANDIDATES 5            // Maximum number of candidates
#define MAX_VOTERS 100              // Maximum number of voters

// Candidate class
class Candidate {
public:
  uint8_t id;
  String name;
  uint16_t votes;  // Vote count for each candidate

  Candidate() : id(0), name(""), votes(0) {}
};

// Voter class
class Voter {
public:
  uint8_t id;
  uint8_t fingerprintID;

  Voter() : id(0), fingerprintID(0) {}
};

// EVMBase class
class EVMBase {
public:
  // Constructor
  EVMBase() : fingerprintSensor(nullptr), candidateCount(0), voterCount(0), loggedIn(false) {}

  // Initialize the system
  void begin();
  // Main loop for handling button presses and user interaction
  void loop();

  // Candidate and voter arrays
  Candidate candidates[MAX_CANDIDATES];
  Voter voters[MAX_VOTERS];
  uint8_t candidateCount;
  uint8_t voterCount;

private:
  // Fingerprint sensor instance
  Adafruit_Fingerprint* fingerprintSensor;
  // Login status flag
  bool loggedIn;

  // Core functions
  void registerCandidate();
  void registerVoter();
  void voterLogin();
  void castVote();
  uint8_t captureFingerprint();
  void indicateSuccess();
  void indicateFailure();
};

// Create EVMBase object
EVMBase evm;

void setup() {
  evm.begin();  // Initialize the EVM system
}

void loop() {
  evm.loop();  // Main loop to handle operations
}

// Initialize the system
void EVMBase::begin() {
  Serial.begin(115200);  // Initialize Serial communication for debugging

  // Initialize fingerprint sensor
  fingerprintSensor = new Adafruit_Fingerprint(&Serial1);
  fingerprintSensor->begin(57600);

  if (fingerprintSensor->verifyPassword()) {
    Serial.println("Fingerprint sensor initialized successfully.");
  } else {
    Serial.println("Error: Fingerprint sensor not responding!");
    while (true); // Halt if the fingerprint sensor is not responding
  }

  // Initialize button pins
  pinMode(BUTTON1_PIN, INPUT_PULLUP);
  pinMode(BUTTON2_PIN, INPUT_PULLUP);
  pinMode(BUTTON3_PIN, INPUT_PULLUP);
  pinMode(BUTTON4_PIN, INPUT_PULLUP);

  // Initialize LED pin
  pinMode(LED_PIN, OUTPUT);
  digitalWrite(LED_PIN, LOW);
}

// Main loop for handling button presses
void EVMBase::loop() {
  if (digitalRead(BUTTON1_PIN) == LOW) {
    Serial.println("Candidate Registration:");
    registerCandidate();
    delay(1000); // Debounce
  }

  if (digitalRead(BUTTON2_PIN) == LOW) {
    Serial.println("Voter Registration:");
    registerVoter();
    delay(1000); // Debounce
  }

  if (digitalRead(BUTTON3_PIN) == LOW) {
    Serial.println("Voter Login:");
    voterLogin();
    delay(1000); // Debounce
  }

  if (digitalRead(BUTTON4_PIN) == LOW) {
    Serial.println("Cast Vote:");
    castVote();
    delay(1000); // Debounce
  }
}

// Register a candidate
void EVMBase::registerCandidate() {
  if (candidateCount >= MAX_CANDIDATES) {
    Serial.println("Maximum number of candidates registered.");
    indicateFailure();
    return;
  }

  Serial.println("Enter candidate name:");
  while (!Serial.available());  // Wait for user input
  String name = Serial.readStringUntil('\n');
  name.trim();

  if (name.isEmpty()) {
    Serial.println("Candidate name cannot be empty.");
    indicateFailure();
    return;
  }

  candidates[candidateCount].id = candidateCount + 1;
  candidates[candidateCount].name = name;
  candidateCount++;
  Serial.println("Candidate registered: " + name);
  indicateSuccess();
}

// Register a voter
void EVMBase::registerVoter() {
  if (voterCount >= MAX_VOTERS) {
    Serial.println("Maximum number of voters registered.");
    indicateFailure();
    return;
  }

  Serial.println("Place your finger for registration:");
  uint8_t fingerprintID = captureFingerprint();

  if (fingerprintID > 0) {
    for (uint8_t i = 0; i < voterCount; i++) {
      if (voters[i].fingerprintID == fingerprintID) {
        Serial.println("This fingerprint is already registered.");
        indicateFailure();
        return;
      }
    }

    voters[voterCount].id = voterCount + 1;
    voters[voterCount].fingerprintID = fingerprintID;
    voterCount++;
    Serial.println("Voter registered successfully.");
    indicateSuccess();
  } else {
    Serial.println("Fingerprint registration failed.");
    indicateFailure();
  }
}

// Authenticate voter login
void EVMBase::voterLogin() {
  Serial.println("Place your finger to log in:");
  uint8_t fingerprintID = captureFingerprint();

  if (fingerprintID > 0) {
    for (uint8_t i = 0; i < voterCount; i++) {
      if (voters[i].fingerprintID == fingerprintID) {
        loggedIn = true;
        Serial.println("Login successful. Welcome, voter ID: " + String(voters[i].id));
        indicateSuccess();
        return;
      }
    }
    Serial.println("Voter not registered.");
  } else {
    Serial.println("Fingerprint not recognized.");
  }
  loggedIn = false;
  indicateFailure();
}

// Cast a vote
void EVMBase::castVote() {
  if (!loggedIn) {
    Serial.println("You must be logged in to vote.");
    indicateFailure();
    return;
  }

  if (candidateCount == 0) {
    Serial.println("No candidates available for voting.");
    indicateFailure();
    return;
  }

  Serial.println("Select a candidate to vote for:");
  for (uint8_t i = 0; i < candidateCount; i++) {
    Serial.println(String(i + 1) + ". " + candidates[i].name);
  }

  while (!Serial.available());  // Wait for user input
  int choice = Serial.parseInt();
  if (choice > 0 && choice <= candidateCount) {
    candidates[choice - 1].votes++;
    Serial.println("You voted for: " + candidates[choice - 1].name);
    indicateSuccess();
  } else {
    Serial.println("Invalid choice. Vote not recorded.");
    indicateFailure();
  }
  loggedIn = false;  // Reset login status after voting
}

// Capture fingerprint
uint8_t EVMBase::captureFingerprint() {
  if (fingerprintSensor->getImage() != FINGERPRINT_OK) return 0;
  if (fingerprintSensor->image2Tz() != FINGERPRINT_OK) return 0;
  if (fingerprintSensor->fingerFastSearch() != FINGERPRINT_OK) return 0;
  return fingerprintSensor->fingerID;
}

// Indicate success
void EVMBase::indicateSuccess() {
  digitalWrite(LED_PIN, HIGH);
  delay(500);
  digitalWrite(LED_PIN, LOW);
}

// Indicate failure
void EVMBase::indicateFailure() {
  for (int i = 0; i < 3; i++) {
    digitalWrite(LED_PIN, HIGH);
    delay(200);
    digitalWrite(LED_PIN, LOW);
    delay(200);
  }
}