#include <EEPROM.h>

const int addButtonPin = 15; // Define the "Add" button pin
const int lookupButtonPin = 2; // Define the "Lookup" button pin
const int deleteButtonPin = 4; // Define the "Delete" button pin
boolean addButtonState = false; // Variable to store the "Add" button state
boolean lookupButtonState = false; // Variable to store the "Lookup" button state
boolean deleteButtonState = false; // Variable to store the "Delete" button state
boolean addButtonPrevState = false; // Variable to store the previous "Add" button state
boolean lookupButtonPrevState = false; // Variable to store the previous "Lookup" button state
boolean deleteButtonPrevState = false; // Variable to store the previous "Delete" button state
boolean dataInputInProgress = false; // Flag to track data input
boolean deleteInProgress = false; // Flag to track delete process
int lastId = 0; // Variable to store the last used ID

struct Entry {
  int id;
  String name;
  String phoneNumber;
  boolean deleted;
};

const int maxEntries = 100; // Define the maximum number of entries
Entry entries[maxEntries]; // Array to store entries
const int entrySize = sizeof(Entry); // Calculate the size of one Entry structure

void setup() {
  Serial.begin(9600); // Set the baud rate to match the one in the serial monitor
  pinMode(addButtonPin, INPUT_PULLUP); // Set the "Add" button pin as input with pull-up resistor
  pinMode(lookupButtonPin, INPUT_PULLUP); // Set the "Lookup" button pin as input with pull-up resistor
  pinMode(deleteButtonPin, INPUT_PULLUP); // Set the "Delete" button pin as input with pull-up resistor

  EEPROM.begin(maxEntries * entrySize); // Initialize EEPROM with enough space for all entries
  loadEntriesFromEEPROM(); // Load existing data from EEPROM
}

void loop() {
  // Read the "Add" button state
  addButtonState = digitalRead(addButtonPin);

  // Check if the "Add" button is pressed and data input is not in progress
  if (addButtonState == LOW && addButtonPrevState == HIGH && !dataInputInProgress) {
    int newId = findNextAvailableId(); // Get the next available ID
    if (newId != -1) {
      Serial.println("ID: " + String(newId));
      Serial.println("Please enter your name:");
      while (Serial.available() == 0); // Wait for user input
      entries[newId - 1].name = Serial.readStringUntil('\n');
      Serial.println("Please enter your phone number:");
      while (Serial.available() == 0); // Wait for user input
      entries[newId - 1].phoneNumber = Serial.readStringUntil('\n');
      entries[newId - 1].deleted = false; // Entry is not deleted
      lastId = newId; // Update the last used ID
      Serial.println("Name: " + entries[newId - 1].name);
      Serial.println("Phone Number: " + entries[newId - 1].phoneNumber);
      Serial.println("Credentials saved!"); // Display "Credentials saved" message
      saveEntryToEEPROM(newId - 1, entries[newId - 1]); // Save the new entry to EEPROM
      dataInputInProgress = false; // Reset the flag to indicate data input is complete
    } else {
      Serial.println("No available IDs. Please delete an entry to free up an ID.");
    }
  }

  //with fingerprint
/*
  if (addButtonState == LOW && addButtonPrevState == HIGH && !dataInputInProgress) {
  int newId = findNextAvailableId(); // Get the next available ID
  if (newId != -1) {
    // Perform fingerprint verification here
    int fingerprintId = verifyFingerprint(); // Get the fingerprint ID
    if (fingerprintId != -1) { // Check if fingerprint is verified
      Serial.println("Fingerprint verified.");
      Serial.println("ID: " + String(newId));
      Serial.println("Fingerprint ID: " + String(fingerprintId)); // Display fingerprint ID
      Serial.println("Please enter your name:");
      while (Serial.available() == 0); // Wait for user input
      entries[newId - 1].name = Serial.readStringUntil('\n');
      Serial.println("Please enter your phone number:");
      while (Serial.available() == 0); // Wait for user input
      entries[newId - 1].phoneNumber = Serial.readStringUntil('\n');
      entries[newId - 1].deleted = false; // Entry is not deleted
      lastId = newId; // Update the last used ID
      Serial.println("Name: " + entries[newId - 1].name);
      Serial.println("Phone Number: " + entries[newId - 1].phoneNumber);
      Serial.println("Credentials saved!"); // Display "Credentials saved" message
      saveEntryToEEPROM(newId - 1, entries[newId - 1]); // Save the new entry to EEPROM
      dataInputInProgress = false; // Reset the flag to indicate data input is complete
    } else {
      Serial.println("Fingerprint not verified. Access denied.");
    }
  } else {
    Serial.println("No available IDs. Please delete an entry to free up an ID.");
  }
}
*/

  // Read the "Lookup" button state
  lookupButtonState = digitalRead(lookupButtonPin);

  // Check if the "Lookup" button is pressed
  if (lookupButtonState == LOW && lookupButtonPrevState == HIGH && !deleteInProgress) {
    Serial.println("Please enter the ID you want to lookup:");
    while (Serial.available() == 0); // Wait for user input
    int lookupId = Serial.parseInt();
    if (lookupId > 0 && lookupId <= maxEntries && !entries[lookupId - 1].deleted && entries[lookupId - 1].name != "" && entries[lookupId - 1].phoneNumber != "") {
      Serial.println("ID: " + String(lookupId));
      Serial.println("Name: " + entries[lookupId - 1].name);
      Serial.println("Phone Number: " + entries[lookupId - 1].phoneNumber);
    } else {
      Serial.println("No data found for the specified ID.");
    }
  }

  // Read the "Delete" button state
  deleteButtonState = digitalRead(deleteButtonPin);

  // Check if the "Delete" button is pressed
  if (deleteButtonState == LOW && deleteButtonPrevState == HIGH && !dataInputInProgress) {
    Serial.println("Please enter the ID you want to delete:");
    while (Serial.available() == 0); // Wait for user input
    int deleteId = Serial.parseInt();
    if (deleteId > 0 && deleteId <= maxEntries) {
      if (!entries[deleteId - 1].deleted && entries[deleteId - 1].name != "" && entries[deleteId - 1].phoneNumber != "") {
        Serial.println("ID: " + String(deleteId));
        Serial.println("Name: " + entries[deleteId - 1].name);
        Serial.println("Phone Number: " + entries[deleteId - 1].phoneNumber);
        Serial.println("Are you sure you want to delete this entry? (Y/N)");
        char confirm;
        do {
          while (Serial.available() == 0); // Wait for user input
          confirm = Serial.read();
        } while (confirm != 'Y' && confirm != 'y' && confirm != 'N' && confirm != 'n');
        if (confirm == 'Y' || confirm == 'y') {
          entries[deleteId - 1].deleted = true; // Mark entry as deleted
          Serial.println("Entry deleted.");
          saveEntryToEEPROM(deleteId - 1, entries[deleteId - 1]); // Save the updated entry to EEPROM
          dataInputInProgress = false; // Reset the flag to allow further data input
        } else {
          Serial.println("Deletion canceled.");
          dataInputInProgress = false; // Reset the flag to allow further data input
        }
      } else {
        Serial.println("Nothing to delete here.");
        dataInputInProgress = false; // Reset the flag to allow further data input
      }
    } else {
      Serial.println("ID not found.");
      dataInputInProgress = false; // Reset the flag to allow further data input
    }
  }

/*
if (deleteButtonState == LOW && deleteButtonPrevState == HIGH && !dataInputInProgress) {
  Serial.println("Please enter the ID you want to delete:");
  while (Serial.available() == 0); // Wait for user input
  int deleteId = Serial.parseInt();
  if (deleteId > 0 && deleteId <= maxEntries) {
    if (!entries[deleteId - 1].deleted && entries[deleteId - 1].name != "" && entries[deleteId - 1].phoneNumber != "") {
      Serial.println("ID: " + String(deleteId));
      Serial.println("Name: " + entries[deleteId - 1].name);
      Serial.println("Phone Number: " + entries[deleteId - 1].phoneNumber);
      Serial.println("Are you sure you want to delete this entry? (Y/N)");
      char confirm;
      do {
        while (Serial.available() == 0); // Wait for user input
        confirm = Serial.read();
      } while (confirm != 'Y' && confirm != 'y' && confirm != 'N' && confirm != 'n');
      if (confirm == 'Y' || confirm == 'y') {
        // Retrieve the associated fingerprint ID
        int fingerprintId = getFingerprintIdForEntry(deleteId);

        // Delete the entry data
        entries[deleteId - 1].deleted = true; // Mark entry as deleted
        Serial.println("Entry deleted.");
        saveEntryToEEPROM(deleteId - 1, entries[deleteId - 1]); // Save the updated entry to EEPROM

        // Delete the fingerprint template associated with the fingerprint ID
        deleteFingerprintTemplate(fingerprintId);

        dataInputInProgress = false; // Reset the flag to allow further data input
      } else {
        Serial.println("Deletion canceled.");
        dataInputInProgress = false; // Reset the flag to allow further data input
      }
    } else {
      Serial.println("Nothing to delete here.");
      dataInputInProgress = false; // Reset the flag to allow further data input
    }
  } else {
    Serial.println("ID not found.");
    dataInputInProgress = false; // Reset the flag to allow further data input
  }
}
*/

  addButtonPrevState = addButtonState; // Store the current "Add" button state for comparison
  lookupButtonPrevState = lookupButtonState; // Store the current "Lookup" button state for comparison
  deleteButtonPrevState = deleteButtonState; // Store the current "Delete" button state for comparison
}

// Function to find the next available ID
int findNextAvailableId() {
  for (int i = 0; i < maxEntries; i++) {
    if (entries[i].deleted || entries[i].name == "" || entries[i].phoneNumber == "") {
      return i + 1; // Return the first deleted or empty ID
    }
  }
  return -1; // No available IDs
}

// Function to save an entry to EEPROM
void saveEntryToEEPROM(int index, Entry entry) {
  int addr = index * entrySize;
  EEPROM.put(addr, entry);
  EEPROM.commit();
}

// Function to load entries from EEPROM
void loadEntriesFromEEPROM() {
  for (int i = 0; i < maxEntries; i++) {
    Entry entry;
    int addr = i * entrySize;
    EEPROM.get(addr, entry);
    entries[i] = entry;
  }
}